pctali 3 cover _wiseues 0 Baie DESEADO ‘TION OF PATAGONTA FREDERIC B. LOOMIS THIS: BOOK TS PRESEN FEED WITH THE COMPLIMENTS OF 0 AE RUS aan Or AMOR BR: bh COA te PLEASE ACKNOWLEDGE TO LIBRARIAN, AMHERST COLLEGE AMHERST, MASS. As A Se As, re me wo. Weiyes erst eae ie ee ane reo Sei eee ce 4 Ve i as ‘ 7 ' i cok a ~ om ea eee ee oe. for, eae var Poa _ san as THE DESEADO FORMATION OF PATAGONIA Digitized by the Internet Archive in 2008 with funding from Microsoft Corporation http://www.archive.org/details/deseadoformation00loomuoft — i an —_ es i al “Clr a8ed 99¢ ‘azIs [eInjeu g/I ‘ourys a Dalle o _ auIy lopuosos uNtI9YyOIAY Jo [[Nys ayy The Deseado Formation of Patagonia Frederic Brewster Loomis, Ph.D. Professor of Comparative Anatomy Amherst College 1911 Be are ey) ae k as \ i | wv\ -\ PUBLISHED UNDER THE AUSPICES OF THE TRUSTEES OF AMHERST COLLEGE 1914. Copyright, 1914 By FRepeEric B. Loomis THE RUMFORD PRESS CONCORD? N! CONTENTS CHAPTER Ee) Organization of the expedition—history of the work done in the DERCAUGTORIMATION pt ae ditn ort ta Ne BR ee eee ees Ae ( Il. Description of the Amherst locality—age of the overlying beds— ~J age of underlying beds—age of Deseado.................... au. Table of the animals—study of the feeding habits—character of “>~ the habitat—the origin of the elements of the Deseado fauna IV. Systematic arrangement—the Litopterna, Eoproterotherium, Notodiaphorus, Deuterotherium, Protheosodon, Conioptero- theruns, [ricoelodus Proadianthus: 5.0.24 seacccatea 450 V. Typotheria, Archaeohyrax, Plagiarthrus, Prohegetotherium, Prosotherium, Propachyrucos, Phanophilus, Archaeophylus, Eutrachytherus, Argyrohyrax, Isoproedrium............. VI. Rhynchippidae, Toxodontia, Rhynchippus, Morphippus, Eu- WERNODE tat dA rts eon Peg iG nor ke eee ek en VII. Leontinirdae, Leontinia, Ancylocoelus....................... VIII. Nesodontidae, Proadinotherium, Pronesodon, Coresodon, Inter- NIPPUS INESONID DUG rs fon se fhe 2 he ME pate te mi ee ia IX. Isotemnidae, Trimerostephanus, Pleurocoelodon, Lophocoelus, Heénricofiiholia: anise BT e hone are itiaghs AAS ta Ac een X<..7. Homalodontotherta; Asmodenss 2.54435 8s Pate GE molt, - Astrapotheria; ‘Parastrapotheritim 2.32. 60.006 eee ea ACN Los EUS LNETIC, -b EOLNCRUNE (5 Mies 2 ree eg te ee Seti XIII. Rodents, Cephalomys, Scotamys, Litodontomys, Asteromys, PGRGCiR Slo 2 once at aa ee ee ae es nk a Wis A ce es XIV. Edentata, Proeutatus, Prozaedius, Stenotatus, Proeuphractus, Peltephilus, Palaeopeltis, Glyptatelus, Hapalops, Octodonto- Eheriuin JOronOdOi ee ae is a neti dais weet a ds cea XV. Marsupialia, Pharsophorus, Notogale, Proborhyaena, Palaeo- thentes, Pilchenia, Callomenus, Pseuhalmarhippus, Parabderi- Awe birds. Pnysorais: LOxOriiss.c: Sets ca.0 fica Gena bbe a PAGE 19 28 53 86 108 122 PREFACE The results of the Amherst Patagonian Expedition were divided into two parts, the general features, to- gether with the narrative, were reported in a separate volume entitled, “Hunting Extinct Animals in the Pata- gonian Pampas,” published in 1913. For this volume has been reserved the description of the material found and such conclusions as are directly derived from that ma- terial. The material on which this work is based has been prepared out and placed on exhibition at Amherst College. The material here described forms a unified body of data, which adds materially to our knowledge of the com- plete animals of the Tertiary period in Patagonia. There are beside this some small collections which offer some isolated new facts, but the working up of these has been reserved for the future for small articles, as the work may come to maturity. The field has only been touched and a vast amount of further work can be profitably done on the horizons im- mediately preceding and following the one described in this volume, after which an interesting study can be made on the evolution of a fauna which developed in a consid- erable degree of isolation. F. B. Loomis. March 18, 1914. THE DESEADO FORMATION OF PATAGONIA CHAPTER “I INTRODUCTION THE material described and the conclusions drawn in the following pages are the results of the Amherst Ex- pedition to Patagonia in I9II; an expedition organized and sent out by the Class of ’96 as a part of their fifteenth reunion. The party consisted of Frederic B. Loomis ’96, Phillip L. Turner ’11, Waldo Shumway ’12, and William Stein of St. Joe, Wyoming, and left Amherst July 1, rg1t, returning the first of February the ensuing year, having spent its time collecting in the early Tertiary beds of Patagonia, as exposed in the Territories of Chubut and Santa Cruz, the aim being to secure from the earlier periods a fuller knowledge of the vertebrate animals, such as the Princeton Expeditions obtained for the Patagonian and Santa Cruz formations. The narrative of the expedition has been told in “Hunting Extinct Animals in the Pata- gonian Pampas.” Material was found in various beds, from the Creta- ceous up to the Lower Miocene; but the major part of the fossils, and most of the facts new to science came from the work in the Deseado Formation. The collections from the horizon were so complete and interesting that this report of the expedition has assumed the form of a monograph of the Deseado Formation, otherwise known as the Pyrotherium beds. The first work in this formation was done by Carlos Ameghino who at various times between 1889 and 1894 collected for his brother, Florentino Ameghino, the latter studying and describing the collections of Carlos, whose 2 THE DESEADO FORMATION OF PATAGONIA trips covered the country from Chubut down to the Straits of Magellan, and the various formations from the Lower Cretaceous to the Pampean or Pleistocene. Carlos Ameghino and his brother, Florentino, for years explored in Patagonia, going summer after summer at their own expense, and in the meantime maintaining a small book and stationery store in La Plata, the profits of which gave the two brothers a living and furnished the funds for the continual expeditions. In the back of the store was the workshop from which came the continuous stream of knowledge in regard to these strange faunas. One of the best pieces of work done by the brothers was the collect- ing and describing of the fauna of the Pyrotherium beds the bulk of which is contained in two papers entitled, Premiére Contribution a la Connaissance de la Fauna mamimalogique des Couches a Pyrotherium, and Mammi- féres Crétacés de l’Argentine, Deuxiéme Contribution, etc., both published in the Boletin del Instituto Geografico Ar- gentino, tomes 15 and 18 respectively. These two papers give names to most of the forms which we found, but the genera and species are based on very fragmentary and in- complete material. It has been a pleasure to find the accu- racy with which these descriptions were made; and our part has been chiefly to supplement and increase the knowledge of the various forms, and to determine from the more complete material the relationships of these strange forms. In some cases we have been able to assemble all the parts of the animals, and in the others to add more or less to the completion of the knowledge of the forms. There is one perculiarity of Ameghino’s descriptions, namely the ab- sence of data as to the localities where the forms were found. About 1900 Tournier, in the interests of the Paris Mu- scum, made a series of expeditions (5) to Patagonia, on some of which he found a Pyrotherium, or as he has termed it Deseado, locality just south of the Deseado River, LOCALITIES 3 from which he gathered a considerable collection which has been described by Albert Gaudry in various papers mostly in the Annales de Paléontologie. These two collections and their collaborations represent all the work thus far done on the Deseado beds and fauna. Our collection is the first one of any considerable size to be brought to North America, and it seems to be by far the most complete, the various animals being represented by more complete skeletons than in any of the previous col- lections. ; The beds were first designated as the Pyrotherium beds, and are always so referred to by F. Ameghino. Tournier and Gaudry, feeling the prejudice which is fairly general among Palaeontologists against names based on any con- tained animal (which may or may not be present at other localities, which may extend through more than one period, and whose name may be changed as a result of further knowledge) used the term Deseado formation, as his collections came from the neighborhood of this river. This is a geographical name and avoids the chance for confusion; so I have adopted it throughout this paper, it being understood as an equivalent of the term Pyrotherium beds. Ameghino never gave the exact, or anywhere near the exact, localities from which his Deseado specimens came. It was not until 1906, when his Formations Sedimentaires* appeared, that any localities were designated, and there on a sketch map he indicates as Deseado exposures, about a dozen points, scattered between the upper part of the Chubut River to some 25 miles south of the Deseado River. These are included in an oval area some 500 miles long by 150 miles wide. Ameghino also suggests on this occasion that the Deseado formation originally extended over at least the whole of this area. As will be seen in the next chapter, I believe that the deposits of this age * Anal. Mus. Nac. Buenos Aires, ser. 3, t. 8, p. 99. 4 THE DESEADO FORMATION OF PATAGONIA and character have always been local and isolated. We sought for several of these localities and failed to locate them, especially those near Mazaredo, and the northern one on the Gulf of St. George. The point where we did find our material I believe was one of Ameghino’s localities, though the settlers of that region had never heard of any- one hunting for fossils there; but the settlement had been practically all within the previous six years, which was much later than the time when Carlos Ameghino worked in the region. Beside the foregoing, an exposure of this age is reported by A. A. Romero, just above the fork of the two branches of the Rio Negro, which is some 500 miles north of the first group of localities mentioned. Ameghino also refers to another locality in the Province of Misiones which would be 1,500 miles north of the typical localities. The collections made by Tournier for Gaudry came chiefly from an exposure south of the Deseado River, some 15 miles above the mouth of the river.* Our collection came from the Chico Branch of the Chubut River, about three miles east of the river, and almost due west of Puerto Visser. As mentioned above on account of the close coincidence of the various species and because Ameghino indicates a locality in the neigh- borhood, I think that our locality is the same as one of his, I should judge it the one from which he obtained a considerable part of his types. This is of importance; for, if in Ameghino’s type locality, the determination of the species, as the same as those of Ameghino’s, is much more certain. In the accompanying map I have indicated the _locali- ties given by Ameghino, those of Tournier, and our own. * Bul. Soc. Geol. France, ser. 4, t. 3, 1903, p. 468. i ares Ags > Bee Ee White Sand +4, een x E el . ei OO ewe See Sa ee Sik ae oe Oma TS “ai Btls Sees : 3? © E NNabis we AN SS S11 SS REN Dae ~ PINON a ! \ NN a “SN Se. \ AANA SNAN € f, Poe Fs Paes 4] LOT OG Ge De Vay Gg by Od PET ES PE MLE Oo OE | Celt Ce ee TAG MALS LG TF LRA Bch See \ FGrey Clay Shales 3 awe L par hirer: ' ones :7 ee hs oa rse “and st SEES Ve tteng Red, Grey oo ee Sis te . Green Shales ALLA YU sis TT y ellow [Saw wee se cess! = SS SS Seren Shales Si Se ee eee Sost § andy Sha les S35 111,04 440606, 941 "7 TT r 3 s/f 14.116, 1G OEE EL LG ESS ARCHER A 4 y Tf nGe Ait le ult th ig lett L Ul T ha Ugg t gts CLA 7/ ft. SS 70 he) 3 70 $0 Fig. 4. Section B on map, page 5, showing strata from sea level up to the Patagonian. SSI EFF Veh THE DESEADO FORMATION OF PATAGONIA being typically developed opposite Pico Salamanca. In this in the neighborhood of Pico Salamanca we found the fauna typical of this horizon. Ostrea rostigera v. Th. Ostrea riongrensis v. Th. Ostrea ameghinoi v. Th. Chlamys salamanca v. Ih. Rostellaria striatissima v. Th. Rostellaria sp. Cytherea calcedonica H. Discinia sp. Diplodon sp. This Salamanca formation is considered by Wilckens as the equivalent of the Roca as exposed on the Rio Negro, and to the Luisa as exposed on the Rio Coyle. ° All agree that the Salamanca is Upper Cretaceous and a period when Patagonia was covered by the ocean. In section B we found the above fauna in layer 1 which is just above sea level here. In layer 2 we found casts of delicate marine shells (30 to 40 in number), representing four or five species and as yet undescribed. They seem to represent a deeper water facies of the Salamanca. In fact all the shales represented by layers I to 5 evidently belong to the Salamanca. Layer 5 was distinguished by having in it at a point some 200 yards north of the section line a quantity of turtle shell fragments. Layer 7, consisting of coarser sandstones, was at the point of the section, simply filled with a vast quantity of fossil wood, most of it agatized, though some was carbon- ized, and representing some eight species, mostly pines and palms, the latter much scarcer. The tree trunks, hundreds in number, lay scattered in all directions; but all were lying horizontal, and there was no indication of stumps in place; so I consider that the wood was driftwood. It is common in the series of beds of this general horizon along the Gulf of St. George. In the other layers up to the Patagonian THE SALAMANCA FORMATION 15 we found no fossils. The contact with the Patagonian was unconformable, in some places being 50 feet higher than in others near by. In section A the typical Salamanca is below sea level, and the lower parts of the section are made up of the white sandy clay shales, so typical all along the Gulf of St. George. In the midst of these clays at the level indicated as 2 oc- curred a layer of concretions. On breaking these we found two specimens of Nautilus valencienni H., clear evidence that they were of marine origin. Layer 5 was filled with hundreds of the very characteristic oyster, described as Ostrea (Gryphaea) pyrotheriorum. Though in. earlier papers suggesting that O. pyrotheriorum represented a horizon of marine sediments corresponding in age to the Deseado (=Pyrotherium) formation, in his Formations Sedimentaires, Ameghino places this fossil in the Sala- manca fauna, though it here occurs at least 275 feet above the typical Salamanca fauna. I believe the layer should be distinguished. It is later than the typical Salamanca, though belonging to the same transgression of the sea over Patagonia. In layer 7 we found still another marine fauna consisting of Ostrea guarantica H. Venericardia sp. Corbula sp. Aporrhais. Patomides. Oxyrhinca. Milobates. Fragments of the limbs of a crab in abundance. This seems to be the same fauna as that described by Ameghino as the Sehuen developed on the Rio Seheun. In layer 8 we found large quantities of gypsum, occur- ring mostly in balls of radiate structure. Layer II was a coarse green sand, and in it we found some fragments of some sort of a bone. I think this layer is what Ameghino 16 THE DESEADO FORMATION OF PATAGONIA designated as a Deseado exposure; and it has the same general appearance and color which is found in the green sands of the Deseado pocket on the Rio Chico. However it is conformable interbedded with the underlying and over- lying marine beds and I consider it a part of the marine series. Above it come more white sandy clays that are characteristic of the most of the section. Wilckens takes all of this series, from the base of the Salamanca, up to the unconformity below the Patagonian, and makes of it his St. George Period, a transgression epoch, lasting to the end of the Upper Cretaceous. I be- lieve it is all marine, and is all a part of the Upper Creta- ceous transgression of the sea over Patagonia. However the Salamanca is a clear cut deposit and I feel it should be retained as a distinct horizon. The overlying light colored (white, grey, brown, yellow, or green) sandy clay shales represent a deeper water and later facies, which is characteristically developed on the Gulf of St. George, and may well be distinguished as the St. George epoch or series, but I should use the term only in this more limited way. It is the same series which Ameghino has plotted as the Notostylops beds on his section of the coast of Patago- nia. This last it certainly is not. The unconformity between these white (or light) sandy clays and the Patagonian represents a regression period, during which Patagonia was not only above water, but extended an unknown distance further to the East. It was during this interval of time between the Upper Cretaceous and the Lower Miocene (Patagonian) that the limited and local land deposits known as Casamayor (=Notostylops), the Astraponotus, and the Deseado (= Pyrotherium) and probably other beds were laid down. In each case the age must be determined for the individual bed by its contents mostly; for as far as I know none of them overlap anywhere. DINOSAUR QUESTION Ff In regard to the discussion as to whether Dinosaurs were contemporaneous in South America with the fauna of the Deseado, I can only say, we found no trace of a din- osaur or any other Cretaceous animal in the Deseado beds which we worked. As the Cretaceous beds lie as high as the Deseado and are also practically horizontally striated, dinosaur remains might be found on the same level. I think the assigning of any such material to these beds was due to failing to recognize the unconformity under the Deseado beds. As to the Notostylops fauna and dinosaurs being contemporaneous, I only worked the Notostylops beds at Mazaredo, but there I found nothing to indicate the contemporaneousness of these two groups. As I have shown above, Ameghino’s idea of the extent of the Noto- stylops or Casamayor beds was mostly at fault, and very much of that which he has designated as of Notostylops age is Upper Cretaceous. It is in these Upper Cretaceous beds that dinosaurs do occur and this seems to me to be the basis of the confusion. This Upper Cretaceous series is a field where consider- able work may profitably be done, in straightening out the relationships of the various layers to each other, their extent, and their relationship to the Salamanca and other Upper Cretaceous formations in other parts of Argentine. As to the age of the Deseado deposit which we worked. It is under the Patagonian, and therefore must be as old as the Oligocene. On the other hand it must be as young as the Eocene, lying as it does above the Upper Cretaceous. Of the three general faunas described it is clearly more ad- vanced than either the Casamayor, or the Astraponotus; so should be put as the youngest of these three. The Colpodon, the Astrapothericulus and the Notohippus, faunas are said to be interstratified with the Patagonian and therefore of the same age. The amount of advance- ment from the Casamayor to the Deseado is considerable and the relationships of the Deseado are fairly close with a: 18 THE DESEADO FORMATION OF PATAGONIA the various genera of the Santa Cruz; so that I should put the Deseado as far up as possible toward the Santa Cruz. The Santa Cruz is above the Patagonian, and I think that the Deseado should be put just before the Patagonian; that is in the Oligocene, but just what part of the Oligo- cene can only be determined when the other faunas have been further studied. CHAT EER Tl THE DESEADO FAUNA THE exposure of the Deseado, which the Amherst party worked, yielded 293 specimens, each presumably repre- senting an individual. (There were besides these a few that were indeterminate and are not therefore included.) The consideration of the fauna as a whole suggests certain ideas as to the country in which the animals lived, and also certain comparisons with the fauna of the preceding and later faunas. The first striking feature is the presence of so many excessively large animals, as Asmodeus, Parastrapotherium, and Pyrotherium, in each case forms larger than a rhinoce- ros. Further than that they are in each case the largest members of their family, even larger than the representa- tives in the later Santa Cruz. This would indicate a period in which living conditions were at a high grade, sug- gesting both abundance of food and a moderate climate. The following table will give a good idea as to the range of species, and their relative abundance in the fauna, also a suggestion as to the class of food they used; and from that an idea as to what sort of country they occupied: Per Nus- SPECIES Foop COUNTRY CENT BER Hegetotherium shumwayi Prosotherium garzoni Prosotherium triangulidens Eutrachytherus grandis ; Eutrachytherus spegazzinius f ies and } Plains Isoproedrium solitarium \ 2 Phanophilus dorsatus Argyrohyrax proavus Plagiarthrus clivus 14% 40 TYPOTHERIA ee Sd Se Oe THE DESEADO FORMATION OF PATAGONIA SPECIES Protheosodon coniferus Notodiaphorus crassus LITOPTERNA Rhynchippus equinus RHYNCHIPPIDAE Leontinia gaudryi LEONTINIDAE Proadinotherium leptognathus Coresodon scalpridens NESODONTIDAE Asmodeus osborni HOMOLADONTIDAE Parastrapotherium holmbergi ASTRAPOTHERIDAE Pyrotherium sorondoi PyROTHERIA Cephalomys arcidens Cephalomys plexus Cephalomys prorsus Asteromys prospicuus Scotamys antiquus Eosteiromys medianus Litodontomys chubutensis RODENTS Proeutatus lageniformis Prozaedius planus Prozaedius depressus Proeuphractus setiger Peltephilus undulatus Palaeopeltis inornatus Indeterminate [EDENTATA Plichenia lucina Epanorthus chubutensis Callimenus praecursor Pharsophorus tenax Pharsophorus mitis MARSUPILAIA 20 PER Num- CENT BER I 15 OO TG 19 RO ee 44 15% 44 2 2 | if 2oat Sas 6 206. “6 II 4% 1 55) 22 19 3 I I I 35% 102 9 I 2 3 I 5 8% 23 I I 5 2 Boor elo cesta iad BirDSs Foop COUNTRY Grass Plains Grass Plains Browse Brush plains Grass or Browse Plains Browse ? Browse ? Browse ? Hard vegetation Open country Insects and leaves Open country Insects and flesh ? Open country THE. EDENTATES at In our collection, all from one point, there are thirty- nine different species. Beside these Ameghino has de- scribed a considerable number of species, some of which in time will probably turn up at our locality; but others and I think the majority will be found to be representative of other localities which he worked. It is to be expected that a difference of locality will make a little difference in the fauna. Further I expect that no two localities represent exactly the same period of time, though they may do so approximately; but some of these local deposits must have been begun earlier, and others probably lasted to a later period. Thirty-nine species of mammals and land birds is a fairly varied fauna for one spot; and the time element involved in laying down the 50 feet which separated the bottom from the top of the Deseado deposit is not probably very long; for the material of which the deposit is com- posed is of a character which would have been laid down fairly rapidly. Of this fauna only 8 per cent belongs to the edentates; and if any element were disproportionately represented it would be this one, for the armadilloes have in addition to the skeleton the hundreds of tiny plates of the carapace, and several of the forms are ‘represented by one or two plates only. When compared with the condition in the Santa Cruz this 8 per cent is strikingly small, for in that later bed, fully 50 per cent of the finds represent edentates. Are the Edentata just originating? Or, was the country less favorable to their habitation? The edentates which we did find are only slightly less advanced in their develop- ment than those of the Santa Cruz. Also, though in- frequent, all of the families of the Santa Cruz are repre- sented. It would seem therefore that the origin of the edentates was much earlier than the Deseado; and this relative paucity of edentates is also characteristic of the Casamayor and Astraponotus beds; but they are there, and in considerable variety, though small numbers. It 22 THE DESEADO FORMATION OF PATAGONIA would seem then that the country for some reason was less adapted to edentates, and that in some other part of South America they were flourishing and evolving. In the Deseado the rodents appear for the first time in South America. ‘They are all //ystricomorpha and in a relatively primitive stage of development, but they are typically developed already. Did they migrate in from some other locality, or were they evolved on the spot? Ameghino believed that they were developed from some such form as Promysops or Propolymastodon of the Casa- mayor, and that these forms were ancestral to rodents all over the world. If my interpretation of the age of these beds is anywhere near correct, this last at least is impos- sible, for in North America and Europe typical rodents are present in the Eocene. Then as to even the hystri- comorphs being developed in Patagonia, | am very skep- tical, for the material offered in evidence of this is very insufficient, especially in the region of the incisors; and may be interpreted in other more probable ways. I am confident that either just before the beginning of the Des- eado, or at the beginning, the rodents of these beds mi- erated, either from some other continent, or at least from some other section of South America into this Patagonian region. Some idea of the type of country and the climate of the Deseado period in Patagonia may be obtained by ana- lyzing the fauna as to the character of its teeth as indicative of the food; and by studying the feet as indicative of the ground on which they were used. The 7ypotheria with their chisel-like front teeth, lack of canines, and their permanently growing grinders evi- dently ate a hard typeof vegetation. Deepand permanently growing molars are characteristic of the eaters of grass, a form of vegetation which is especially hard on the grinding teeth, on account of the silica in the stems and leaves. This however would scarcely necessitate the development THE TOXODONTS 23 of permanently growing incisors. They are typical of gnawing animals, eaters of bark, twigs, and possibly also leaves, the wood and bark being also a hard type of vegeta- tion togrind. In the case of these forms I believe they were feeders on grass and bark. Their feet are developed either for running or hopping and would suggest hard ground for their habitat. The Litopterna are typically plains animals, paralleling in their development the horses. The cropping teeth and the grinding molars become progressively longer. The limbs are progressively elongated, the animals walking more and more on the tips of the toes. With this, the metapodials especially and the other limb bones to a less degree, are progressively lengthened. At the same time the side toes are progressively reduced. The teeth indi- cate grass eating; the limbs life on the plains. The Rhynchippidae, while not as advanced as the Litop- terna, show cropping front teeth, and the molars develop- ing in depth. The locomotion is semidigitigrade, the feet small, and the number of toes reduced to three. They too must be interpreted as grazing or grazing and browsing animals, living on hard ground. The Leontinidae are heavier forms, but with much the same features as Rynchippidae, though less specialized. On account of the broad upper molars and the less special- ization of the dentition, I should feel that these forms were browsers and lived among bushes, but the feet were three toed and semidigitigrade and they seem to have walked on hard ground. The Nesodontidae belong to the same type of adaptation as the foregoing family, but have the grinding teeth more complicated, indicative of a more advanced adaptation to hard vegetation. The feet were also adapted to hard ground. The Homalodontotheria, the Astrapotheria, and _ the Pyrotheria were all very large animals, known mostly by 24 THE DESEADO FORMATION OF PATAGONIA their dentition, which is adapted to browse. Whether they lived on soft or hard ground is not known, as the feet are not known in any case but the Homalodontotheridae, where they are five toed and adapted to soft ground. Such large animals were probably inhabitants of some river bank. The rodents do not contribute much in the determina- tion as to the type of the country, for they could have lived in the open or in the wooded country, but their relative abundance is rather typical of open country. The birds are all running birds, and indicative of the country having been an open one. Of our fauna I1 per cent were flesh or insect eating, and for the purpose of determining the type of country may best be omitted. The rodents could have been either forest or open country forms. Of the remaining 54 per cent, the typotheres, the litopternas, the Rhynchippidae, the Leon- tinidae, the nesodonts and the birds (46 per cent) were distinctly adapted to live on hard ground; the other 8 per cent being evidently suited to living near a river. All 54 per cent ate either grass or browse. The litopternas are grass eaters; the typotheres were specialized to eat grass or bark; nesodonts, Leontiniidae, and Rhynchippidae are grass and browse eaters. Even the Pyrotherium has a pair of gnawing tushes. The picture arising from these con- siderations is a bush covered prairie, a country not unlike the upland bush pampas of Patagonia today. There is not an aquatic form (fish or turtle) in the whole list, so it is evident that the stream which deposited these Deseado beds was not abundantly inhabited. To me it looks like so many of the streams in an arid country, dry through a considerable part of the year, and so uninhabited. In the whole list I see nothing to indicate forests or swamps. The arid bush covered plain alone seems to suit the re- quirements, As I see this fauna it is composed of several distinct elements, representing different invasions and an ele- VARIOUS INVASIONS 2 mn ment which arose in situ. The reasons for the affinities expressed in the different groups will be found in the intro- ductory paragraphs of the systematic discussion of each group. : The Notungulata, including the Typotheria, the Toxo- dontia, the Litopterna, the Homalodontotheria, and the Astrapotheria are a group with apparently a common an- cestry. In Patagonia they have specialized into the various subdivisions as we find them in the Deseado. This group was in Patagonia as early or earlier than the Casamayor. Their relationships appear to me to be with the //yracoidea which are generally credited with originating in Africa. The Pyrotheria are related to the early elephants which also arose in Africa, but it seems to me that this form came to Patagonia at least at a later period, making its first appearance in the upper part of the Astraponotus period. Ultimately the elephants and Hyracoidea had a common origin in Africa. The Rodentia are all hystricomorphs and appear in South America for the first time in the Deseado. They also occur in the Oligocene of Europe and the Fayum of north Africa. They never reached North America so must have come to South America by some southern route. The Edentata are an element of the Casamayor fauna and as there is no evidence of their originating anywhere else it would seem that they were indigenous to South America, where they later flourished and developed the greatest variety and profusion of numbers. The group of marsupials is an element the origin of which presents a most difficult problem. Some belong to the oppossum series which could well have been developed from some remnant of the Mesozoic marsupial fauna that had a world wide distribution; but the presence of dipro- todonts, which are characteristic of Australia, and of the Borhyaenidae which are closely related to the Thylacinidae of Australia, suggests a migration from that continent as 26 THE DESEADO FORMATION OF PATAGONIA late as Tertiary times; but to my mind this involves a connection which is most too difficult to postulate. There is no evidence that they came to South America in com- pany with other faunas, for they have not been found associated with any other fauna outside of Southern Pata- gonia. ‘The explanation of the affinities of the Patagonian marsupials with the Australian marsupials is a problem which is not yet in position to be settled. The birds probably came from Africa with the invasion of the ancestors of the Notungulates. The idea of an invasion from Africa in Upper Cretaceous times, and possibly another at a later time is correlated with the other evidence of a land bridge between these two continents, as deduced by students of other groups. Kigenmann, working on the freshwater fishes,* LL.ydekker, studying the hystricomorphs, t Von Ihering, studying the freshwater mussels, { Ortmann, studying the freshwater crabs,$ not to mention several others studying mullocks, insects, plants, etc., have all postulated a land connection from Brazil to northern Africa during Cretaceous time to ex- plain the distribution of their various groups. ‘The diver- gence is in the time when this land bridge sank, some be- lieving it to have lasted into Tertiary times, most feeling that it sank in Upper Cretaceous times. Another body of evidence is presented to show that a land bridge con- nected the West Indies with the Mediterranean regions.|! There was presumably but one such transatlantic connec- tion. Its position further to the south would seem to me to explain the distributional facts found in the West Indies, but the striking resemblances between the faunas of Africa * Princeton Expeditions to Patagonia, vol. 3, p. 310, 1905-11. } History of Mammals, p. 127, 1896. t Archhelenis and Archinotis, p. 125-145, 1907. § Proc. Amer. Philos. Soc. Philadelphia, vol. 41, p. 350, 1902. || See Scharff, Distribution and Origin of Life in America, Ch. 11, 1912. SOUTH AMERICAN—AFRICAN BRIDGE aay and South America require a connection from the South Upper American Continent and Africa. It was along this land bridge which the ancestors of the Notungulata traveled, and when in South America, due to their isolation, developed all the peculiarities of the group. This must have been not later than the latter part of the Cretaceous. Either this bridge remained until into the early Ter- tiary; so the Pyrotheria and Hystricomorpha made their migration later, or these two groups did not reach the isolated Patagonian section until later than the first inva- sion. I am inclined to believe in the migration being at a later period. This bridge does not explain the presence of the edentates, for which there is every reason to believe that they developed in situ. The Marsupial invasion must have been from some other direction, or their presence in Africa has not yet been discovered. GEAPTERSTV UNGULATA The systematic arrangement of the South American ungulates is of such a nature that scarcely two students of these forms have agreed. I feel that the Pyrotheridae are proboscideans as did Ameghino, but there my agreement ends. The other varied groups I believe have a common ancestry, their great divergencies being due to adaptations to the greatly varied characters of the country they occu- pied. In spite of the great variation they have certain features in common so that I agree with those who have developed the term Notungulata to include them all. From what source they originally came is not clear, but it seems to me that these notungulates have more in com- mon with what we know of the African fauna of the Fayam than with any other fauna; so that my feeling would be that these two faunas had a common ancestry at least, and possibly the South American ungulates are derived from the African. The lophiodont upper dentition, the bicres- centric lower molars with a “pillar’’ in the posterior crescent, the development of the tympanic bulla with the extension of the inflated cavity up into the squamosal bone, the development of the post-tympanic portion of the squa- mosum, and the general arrangement of the basi-cranial foramena indicate in my mind that these notungulates have all risen from the same stock, and that that stock had much in common with the hyracoids. I should therefore arrange the various groups as follows.* * The following references discuss in detail the arrangement of these forms. Ameghino, 1906, Formations Sedimentaires, Anal. Museo Nac. de Buenos Aires, ser. 3, t. 8, p. 287-498: Roth, Los Ungulados Sudamericanos, Anal. Mus. La Plata, t. 5, 1903, p. I-36: Scott, Princeton Patagonian Expeditions, vol. 6, p. 287-299, 1912: Gregory, Bul. Amer. Mus. Nat. Hist., vol. 27, p. 2IB=285;, LOLO. SYSTEMATIC ARRANGEMENT 29 NOTUNGULATA Order 1. Upper molars composed of an external longi- tudinal crest and two transverse crests, the posterior the less developed; lower molars composed of two joining cres- cents with a “‘pillar’’ in the posterior crescent; structure of the feet and limbs varying. Suborder 1. Litopterna: teeth brachydont to hypsodont; lower molars with the anterior and posterior cres- cents subequal; squamoso-periotic region not in- flated; limbs elongated; pes unguligrade; digits 3-3 or I—I. Suborder 2. Typotheria: teeth hypsodont lower molars with the anterior crescent shorter than the poste- rior; squamoso-periotic region inflated; limbs elongated in varying degrees; pes plantigrade to semi-plantigrade; digits 5—4 or 4-4. Suborder 3. Toxodontia: teeth brachydont to hypso- dont; lower molars with the anterior crescent shorter than the posterior; squamoso-periotic region in- flated; limbs short; pes semidigitigrade to digiti- grade; digits 3-3. Suborder 4. Homolodontotheria: teeth brachydont; lower molars similar to those of Toxodontia; limbs moderately eclongate; pes semidigitigrade; digits with large curved claws, 5-5. Suborder 5. Astrapotheria: teeth brachydont to mod- erately hypsodont; canines enlarged into tushes; molars similar to those of Toxodontia; limbs greatly elongated; feet unknown. PROBOSCIDEA Order II. (see page 68) Suborder 1. Pyrotheria: incisors developed into tushes; molars bilophodont; limbs short, especially the lower element; feet digitigrade. 30 THE DESEADO FORMATION OF PATAGONIA LITOPTERNA This order of South American ungulates is less abun- dantly represented in the Deseado formation than in the Santa Cruz, but most of the genera of this latter formation have representatives in the Deseado so that they seem to have diverged still earlier. By Scott the order is divided into two families, the Proterothertidae and the Macrauchenidae, the less known Adiantidae being placed under the latter family until better known. I feel that I should prefer to retain the Adiantidae for the present, until they can be shown to be subordinate to another family, so that in this paper the three families are retained. The striking features of the two larger families may be best brought out by a compari- son of their chief features as follows. Proterotheriidae 1043 2).0. 403 Formula Upper inc. 2 and lower inc. 3 enlarged and tush-like, growing from per- sistent pulps. Nasals normal Neck short. Feet with median digit enlarged, lat- eral digits reduced. Macrauchenidae EAS BNt4s3 Incisors, canine, and premolar 1 simple, compressed, subequal in size, and rooted. Nasals shortened indicating a pro- boscis. Neck long. Feet with all three digits subequal in size. Proterotheriidae Ameghino In the Deseado, this family is scantily represented as compared with the rich fauna, both as to species and num- hers of individuals in the Santa Cruz, but of the four chief ecnera of the Santa Cruz, three have been found, though the remains are very fragmentary. They are the genera Koprototherium, belonging to the Prototherium scries, Deuterotherium belonging to the Thaotherium series, and Notodia phorus representing the Diadiaphorus series. EOPROTEROTHERIUM 31 The following table will give what is known in comparing the two series. PERIOD Upper MOoLarRs NASALS PEs Proterotherium Santa Cruz metaconule present normal _ tridactyl protoconule and protocone separate Eoproterotherium Deseado metaconule present protoconule and protocone separate Licaphrium Santa Cruz metaconule present normal tridactyl Diadiaphorus Santa Cruz metaconule present short tridactyl protoconule and protocone fused Notodiaphorus Deseado tridactyl Thaotherium Santa Cruz metaconule lacking normal monodactyl protoconule and protocone separate Deuterotherium Deseado metaconule lacking protoconule and protocone separate Eoproterotherium Ameghino Eoproterotherium Amegh., g04, Anal. Mus. Nac. B. A., ser. 3, t. 3, p. 441. The genus is founded on single teeth of the upper molar series, which, except for size, are very like those of Proterotherium. Limbs, etc., are unknown, so. that this genus is simply a carrying back of the Proterotherium line into the Deseado. We found no teeth of _ Fig. 5. A, Eoproterotherium this’ form, but one species ‘has’ been Bewieces. Bint uppes mo ; ; Aes 3 , bee Garo described, E. inaequifacies, of which (t™ momen, ‘ad . ’ aft Ameghino. I reproduce Ameghino’s figure com- “ “™**"" pared with Proterotherium, which shows this species to have the metaconule better developed. Notodiaphorus gen. nov. The basis of this genus is particularly a hind limb found associated which is much less developed than the Santa Cruz genus Diadiaphorus to which it is most nearly related. These two genera are unique in having the ectal facet on Bz THE DESEADO FORMATION OF PATAGONIA the astragulus developed in two planes so that it appears as a deep notch. In the case of the new genus the toes are almost equal in size, giving us a stage in the develop- ment of this three-toed form which is much more primitive than the well-known Santa Cruz genus. Notodiaphorus crassus sp. nov. The specimen selected as type is number 3287 of the Amherst Collection, consisting of a complete pes, tarsus, lower end of the tibia, and the femur, from the Deseado on the Chico del Chubut River, west of Puerto Visser. Beside this, there are seven other speci- mens, mostly parts of hind limbs, but others having also the lower end of the humerus, the radius and ulna, metacar- pals, and some phalanges. The species is distinguished by its large size, being larger than the species of the Santa ee z Cruz, and, at the same time, the three Fig. 6. Distal end of right toes of both the pes and the manus are numens ieee eibequal im size. The distal end of the humerus associated indirectly with this species is moderately heavy, with fair-sized epi- condyles, and no entepicondylar foramen. The supratro- chlear fossa is moderately deep, the anconeal very deep, the two being connected by a small foramen, as is typical for this family. The trochlearis, slightly oblique to the long axis of the shaft, has a simple pulley-like articular end without ridges of division, the internal border being narrower and higher than the external. MEASUREMENTS, SPECIMEN 3201 Humerus, greatest diameter of the distal end 58 mm. width of trochlea on the anterior side 37 mm. width of trochlea on the posterior side 28 mm. NOTODIAPHORUS CRASSUS 33 Fig. 7. Right radius and ulna, distal Fig. 8 Left femur posterior side—1/2 natural size end of ulna from specimen No. 3275 1/2 natural size. 3 34 THE DESEADO FORMATION OF PATAGONIA The radius and ulna were from another specimen which, however, was associated with a typical astragulus. The two bones are long, slender, strongly curved, and in con- tact with each other throughout their entire length, so that there could have been no rotary movement of the fore- arm. The radius is a slender bone with the proximal articular facet relatively small, the facet being slightly concave, of ovoid outline and with the transverse diameter the greater. There is but a tiny band-like facet for the ulna situated on the posterior side near the inner margin. Distally, the radius widens into a heavy end with a rugose area on the outer side for contact with the ulna, and with two distal facets, a larger for the scaphoid, and a smaller for the lunar, the two being separated by a low ridge. The ulna is heavier above, with a strong backwardly directed olecranon process. The sigmoid notch makes almost a semicircle, the articular surface being broad and extending well onto either side of the bone. The facets for the radius are tiny. The distal end of this bone is wanting. MEASUREMENTS, SPECIMEN NO. 3275 Radius, length 251 mm. greatest width at proximal end 28 mm. greatest width at distal end 36 mm. least diameter of shaft 16 mm, The femur belongs to the type specimen which is about 5% larger than the other specimens. This bone is long and rather slender, with the greater trochanter rising well above the head, which is rounded, on a short neck, and has the ligamentary pit on the posterior margin. The thick, rugose, greater trochanter bends in over the head at its upper end. The lesser trochanter is relatively small, and prolonged into a ridge. Unfortunately the third tro- chanter is broken off in my specimen. The digital fossa is extremely large and deep. Proximally the shaft is flattened, but becomes rounded distally. Just above the NOTODIAPHORUS CRASSUS 35 condyles there is a deep rugose pit for the plantaris muscle, and on the anterior side the suprapatellar fossa is well marked. The condyles are placed a trifle obliquely; the internal one being shorter and with a rounded articular face, the external condyle being longer, and with a flat- tened articular face which slopes obliquely inward. Of the tibia, only the distal end is preserved. This in- dicates a rather slender bone, with a shal- low, fairly wide concavity for the external astragular trochlea, and a narrower and deeper concavity for the internal astragu- lar trochlea. On the internal side of the tibia there is a rugose surface for the fibula. An isolated lower end of a fibula indi- cates a slender bone, enlarged distally where it comes in contact with the tibia. The fibula carries on its inner face a mod- erately large facet for the external side of the astragulus, and on the distal end a wider one for contact with the calcaneum. The tarsus is compactly built, wider than that of Diadiaphorus, because the external digits are not as much reduced. This especially shows in the greater de- Fig o. Distalendof left velopment of the cuboid and the meso- ary eee rece cuneiform, but in other features it is similar to that of its descendant. The astragulus is a very characteristic bone. The trochlea is asymetrical, the external condyle rising higher than the internal, and the median groove being wide and shallow. On the nearly vertical outer face of the astragulus, there is asemicircular band-like facet for the fibula. The trochea extends well around the top of the bone, allowing a wide movement of the foot. The neck of the astragulus is long and wide, carrying a broad flattened head, with its con- vex facet for the navicular, covering the entire end. On 36 THE DESEADO FORMATION OF PATAGONIA Fig. 10. Left pes, dorsal side, ungual phalanx from specimen No. 3275—1/2 natural size. NOTODIAPHORUS CRASSUS oF the plantar side are the most marked features. The ectal facet is in two planes, the anterior portion being bent down to nearly right angles with the posterior, which seems to be characteristic of this Diadiaphorus series. ‘The susten- tacular facet also is characteristic, being gently rounded and extending clear to the navicular facet on the head, in Diadia- phorus becoming actually confluent with Ge aac the navicular facet, jut at the edge Of: planisraie: 4: kejaliau this-sustentacular facetis a) diny sutiace teptacular facet, cufacet where the astragulus rubs on the cuboid, the only case, as far as I am aware, where this occurs in any Litopterna. The calcaneum is long and slender, the tuber being but slightly enlarged, its sustentacular facet being a broad oval surface, while the ectal facet is in two planes to cor- respond to that on the astragulus. The facet for the cuboid is at the distal end, but is unusually oblique, its inner margin sloping up almost to the sustentacular facet. It is this slope which brings the cuboid in contact with the astragulus. The navicular is broad and-low, with a prominent hook behind. On its upper face there is only the broad facet for the astragulus head; on the lower face are three facets, externally, a large, more or less triangular area, for the ectocuneiform; medianly a smaller similar facet for the mesocuneiform; and on the internal side, sloping up onto the internal face, a small facet for the reduced endocunei- form. On the external face of this bone there is a tiny beveled facet for the cuboid. The endocuneiform is a large scale-like ossicle articulating on the lateral internal face of the navicular, and over- lapping markedly the inner surface of Metatarsus IT. The mesocuneiform is considerably reduced in_ size, carrying a broad flat facet on the upper surface for the 38 THE DESEADO FORMATION OF PATAGONIA navicular, and a shallow saddle-like one below for Mt. II, which is entirely carried by this bone. The ectocuneiform is considerably larger than the meso- cuneiform, resting above on the navicular, and carrying below the whole of Mt. III. On its inner side are two facets which rub against the upper end of Mt. II. The cuboid is a nodular bone, its upper surface occupied by the facet for the calcaneum, the lower face occupied by the facet for Mt. IV, while on the external side * there is a tiny beveled facet for the vestige of Mt. V, and with a small boss on the inner surface which carries two tiny facets, the upper Fig. 12. Cuboid One for the ectocuneiform and the lower for the internal side to show: a, facet navicular. On this same inner side, near the for astragulus ; b, upper facet toy there is a second small boss, which carries for navicular; c, facet for calcav- ii i lever a: tiny -dacet tO rub, wom the. astragulus,. and lar; efacetfor below that a second tiny facet for the navicular. mes natural The pes consists of three digits, with a vestige nae of Mt. V. Of the developed digits, the median one is the largest, but the two lateral digits are only a little smaller and were functional, so that this form was truly three-toed, comparable in the digital reduction to Meso- hippus. Mt. Il is flattened above but soon broadens into a rounded shaft of considerable length, on the end of which is the articular trochlea, with the carina extending onto both the upper and lower surface, being, however, higher on the lower surface. Proximally this bone is overlapped by the endocuneiform, is carried by the small mesocunei- form, and also articulates on the inner side of the ecto- cuneiform. Mt. III is also compressed at the upper end, broadens below, and carries an articular trochlea similar to that of Mt. II, except that the carina does not extend so far onto the upper surface. Like Mt. II, Mt. IV is carried high on the tarsus, and therefore, though nearly as long as Mt. ITI, it does not have the same effective length. NOTODIAPHORUS CRASSUS 39 Proximally it articulates entirely on the cuboid; distally it has a trochlea similar to that of Mt. II, the carina extend- ing onto the dorsal surface. While Mt. V is lacking, it is clearly indicated that a vestige of it should have been present, as there is a tiny articular surface for it on the cuboid, and a rugose surface on the outside of Mt. IV. The phalanges are long and have the articular ends swollen somewhat as in camels. The phalanges of the first row are nearly equal in size, each with the proximal trochlea deeply notched for the carina of the metatarsus; and with the distal trochlea simple, though slightly concave from side to side, and reflexed well onto the dorsal surface. The phalanges of the second row are shorter and simpler, and somewhat depressed distally. The ungual phalanges are flattened from top to bottom, of moderate size, some- what longer than wide, and without any indications of a cleft. MEASUREMENTS, SPECIMEN INO! 3287 00NO: 3275 Femur, length 289 mm, diameter across gr. trochanter 80 mm. diameter of middle of shaft 32 mm. diameter of distal end 70 mm, Tibia, diameter of shaft 28 mm., 24mm. diameter at distal end 38 mm., 36 mm. Calcaneum, length : 103 mm., 96 mm. width 36 mm., 35 mm. Astragulus, length 48 mm., 44 mm. width 38 mm., 35 mm. Metatarsus I], length 114 mm., 105 mm. Metatarsus III, length 122 mm., 114 mm. Metatarsus IV, length 110 mm., IOI mm. Phalanx 1 of digit III, length 49 mm. Phalanx 2 of digit III, length 27 mm, Phalanx 3 of digit IIT, length 29 mm. Deuterotherium Ameghino Deuterotherium Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 633. Deutorotherium Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 452. This genus was first founded on a clacaneum and a bit of the mandibular symphysis, to which were added, later, 40 THE DESEADO FORMATION OF PATAGONIA both the upper and lower premolar and molar teeth. As far as it is known, it is distinguished by the upper molars lacking the metaconule entirely, and being approximately like those of Thaotherium. The dental formula is given 043 by Ameghino as 734, the same as Thaotherium. But one species has been described. Deuterotherium distichum Ameghino We did not find this species, but the teeth assigned to it are very characteristic, and so I reproduce Amegh- ino’s hgure of them. The species is distinguished by Fig. 13. Upper pm. 3-m. 3 of the left side— natural size, after Ameghino. its size primarily. The fol- lowing are the chief measurements given Upper dentition, pm. 3 to m. 3, length 50 mm. Lower dentition, inc, 1 to m. 3, length 80 mm. Macrauchenidae (= Mesorhinidae Amegh.) This family is distinguished, first, by the complete dental series in which none of the anterior teeth are devel- oped into tushes; by the nasals being shortened, apparently in connection with the development of a proboscis; by its long neck; and by its feet being permanently tridactyl, all the three toes being equally developed. In the Deseado it is infrequent, but toit Ameghino has assigned two genera; Protheosodon, which he describes as similar to 7Theosodon, but which I find much nearer to the Casamayor repre- sentatives of this family, such as Lambdaconus, though it doubtless belongs to the series which is represented in the Santa Cruz by Theosodon. He has also made a second genus, Conioptotherium, which represents a large Macrau- chenid, equal in size to Theosodon. This genus is based on the calcaleum and astragulus and seems to be rare. PRIMITIVE MACRAUCHENID 41 Protheosodon Ameghino Protheosodon, Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 453. Protheosodon, Amegh., 1904, Anal. Mus. Nac. B.A., ser. 3, t. 3, p. 421. This genus was founded on an upper second molar and the fourth premolar. I figure m. 2, and it will be seen that they represent a form little specialized, resembling in the low crowns, plump cusps, and presence of both protoconule and metaconule, the Casamayor types, such as Lambdaconus or Didolodus, rather than the advanced type like the Santa Cruz genus, Theosodon. We found a specimen with the lower jaws complete and with the hind limb complete, which, I am confident, is the same form, though I can not duplicate any tooth, for we found no upper teeth; but in size they agree with Protheosodon, also in the primitive character; and, were one from the lower teeth to postulate the upper, they would be just such as Ameghino has de- scribed under the name Protheosodon. Therefore I have assigned my material to this genus and species. It adds to the genus characters the fact that this form had a shorter back, relatively as well as actually, than 7Theosodon; that the hind limb, at least, was much heavier and also shorter than that of Theosodon, especially in the metatarsal region where relatively the elements are only about half as long. The pes is of the same character as in Theosodon, but again relatively much shorter. I believe in Prothesodon we have to do with a form intermediate between Lambdaconus and Theosodon, and nearer to the former. Protheosodon coniferus Ameghino. P. coniferus Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 453. Ameghino has described two upper teeth. Specimen No. 3001 of the Amherst Collection from the Chico del Chubut River, west of Puerto Visser, adds to this the knowledge of twelve vertebrae (seven dorsal and five lum- bar), the lower dentition complete, the left hind limb 42 THE DESEADO FORMATION OF PATAGONIA complete, and the right hind limb complete except for the femur. In general, the animal is about % the size of Theosodon garrettorum, but in parts varies from this as follows. The lower jaw is 2, the vertebrae are = in length, the hind leg a. Shee Bye z is 5 in length but { in diameter of bones, : while the metatarsus is only 4 in length. Fig. 14. Upper mo- Lhis makes an almost plantigrade form of lar. 2 of the right . side—natural _ size, heavy, clumsy proportions. after Ameghino. oene Of the upper dentition we know only what Ameghino has given us. The molar is distinguished by the presence of both the protoconule and metaconule, by the development of the posterior cingulum and by the presence of three external styles. MEASUREMENTS Upper premolar 4, length 12 mm., width 15 mm. Upper molar 2, length 14 mm., width 17 mm. In the lower dentition, none of the teeth are reduced, and all are in a continuous series, except that there is a Fig. 15. Right lower dentition—natural size. small diastema either side of pm. 1. The incisors are simple, compressed teeth, with but a trace of a cingulum. The canine is incisiform and a trifle larger than the incisors. Premolar 1 is also incisiform, and is isolated by a small diastema on either side. The second premolar is longer and wider than the first, and begins to show molariform characters, the anterior portion being composed of a high compressed cusp, the posterior portion by a low crescent on which but one cusp is fully developed. The third pre- molar is composed of two complete crescents, and has the PROTHEOSODON CONIFERUS 43 “pillar” already developed opposite the posterior end of the back crescent. In fact, the tooth is molariform, except as to the tiny extra cusp found on the molars. Premolar 4 is more completely molariform consisting of the same parts as the preceding tooth. The molars may be distinguished by the presence of a tiny median cusp on the rear of the tooth, behind the cres- cent, which, when the tooth is worn, makes a median spur to the rear. In both the premolars and molars, the teeth are characterized by their plumpness, and the isolation and lowness of the cusps. The two halves of the lower jaw are completely fused at the symphysis. The horizontal ramus is thick, but low dorso-ventrally, giving the appearance of a slender jaw. The posterior angle is prolonged backward and bent in- ward. The fossa for the masseter muscle, while large, is but faintly outlined. The ascending ramus hardly rises above the level of the teeth, except as the slender coronoid projects to a good height above the articular condyle and curves backward over it. 44 THE DESEADO FORMATION OF PATAGONIA MEASUREMENTS Lower dentition, total length . 114 mm. incisors, length 20 mm. canine, length 8 mm. premolar 2 to 4 35 mm. molar I to 3 42 mm. Mandible, total length 188 mm. height under molar 1 24 mm. height to top of coronoid 95 mm. The dorsal vertebrae have short, wide, and somewhat depressed centra (in this individual the epiphyses are free, though this is the only indication of youth). The lower rib facets are small, that on the posterior margin of the centrum being a mere streak, while the one on the anterior margin is narrow. The upper rib facet is a rounded convex surface on the end of a short stout transverse proc- ess. The prezygapophyses are convex surfaces, wide transversely, but narrow in the anteroposterior direction, while the postzygapophyses are correspondingly narrow concave facets under the rear of the spines. The spines are thin and high, and the neural canal is nearly circular in section. The lumbar vertebrae have laterally compressed, deep centra, with very long transverse processes, shorting spines, and zygapophyses of the subcylindrical interlocking type. In all their features the vertebrae resemble those of Theo- sodon, being nearly as highly specialized and in the same manner. MEASUREMENTS OF TYPICAL VERTEBRAE Dorsal vertebra No. 7, length 23 mm. width of centrum 22 mm. Dorsal vertebra No. 9, length 28 mm. Lumbar vertebra No. 2, length 29 mm, Lumbar vertebra No, 2, width of centrum 24 mm. Lumbar vertebra No, 2, width across transverse processes 160 mm. The femur is short and very stocky. ‘The rounded head is carried on a short neck, and does not rise nearly as high as the greater trochanter, the sulcus for the round liga- PROTHEOSODON CONIFERUS 45 ment being a broad, deep notch on the posterior margin. The greater trochanter is rugose, heavy, and high, but not incurved at the top. The lesser trochanter is a small, thin ridge well below the head. The third trochanter is a large, thin process, projecting almost directly backward, though curved inward at the end, and is situated well below the a eats Oh a ehO lanai eee middle of the bone. The shaft of the femur is flattened above, but thick, and changes in the lower part to subcy- lindrical. The condyles are small, subequal in size, and widely separated, while the rotular trochlea is relatively wide and shallow. The tibia is about three-fourths the length of the femur, very stocky and heavily built. On the proximal end, the 46 THE DESEADO FORMATION OF PATAGONIA convex cxternal condyle is much narrower anteroposte- niorly than the larger and slightly concave internal condyle. The low spine is bifid. A cnemidial crest extends to the middle of the bone. On the distal end, the broad and shal- low external articular facet is separated from the narrow and deeper internal facet by a low intercondylar ridge. The fibula is fused to the tibia at the upper end, but is free below, being approximated to the tibia along a rugose surface nearly an inch long. This bone is rather slender and strongly bowed outward. Distally, there is a large facet for the outside of the astragulus, the back part of which rests on the calcaneum. This is peculiarly devel- oped so that the articulation represents what is two separate facets, the one for the outside of the astragulus the other for the caleaneum. Here, however, they are blended. While in general the tarsus is similar to that of Theosodon, there are some marked contrasts. The astragulus has phalanges in outline from the left foot—1/z2 natural ae an asymetrical tro- chlea with a_ shallow groove, the external condyle being higher Oe and narrower than the internal. The P 4 head is depressed in the dorso-plantar = “This'troch- 42075. Gaiescewn: lear surface is far from: being symmetrical, #sttaeulus_and cuboid: the inner ridge being much flatter and lower “*'** than the outer. The head of the astragulus is rounded, on a long neck, and directed obliquely inward. The fibular facet for the fibula is crescent-shaped and vertical Fig.38. Astragulusfrom EXCept that the small below—natural size. - proximal end of the cres- cent flares out. The outline of the sus- tentacular facet is that of an acute ovoid, and is situated mostly on the neck of this bone. The ectal facet is roughly rectan- gular in outline, strongly concave, and is separated from the sustentacular facet by a deep groove. The calcaneum is of moderate size, has a narrow fibular facet,a broad ectal facet, and a moderately large sustentacular one. The facet for the cuboid is slightly concave, and occupies the whole of the distal and of the calcaneum. The metatarsals are moderately long and rather heavy, not quite as long Fig.30. Right foot—natural and slender as those of Pachyrukhos. es The phalanges are also shorter and slightly heavier than those of Pachyrukhos. We found four proximal and four of 70 THE DESEADO FORMATION OF PATAGONIA the second series, all associated, which probably indicates the full number of the toes. The ungual phalanges are proximally narrow and high, then expand toward the tip, developing into marginal expansions. ‘There is but a trace of a cleft in the end of these ungual phalanges. MEASUREMENTS Skull, greatest length 99 mm. Upper dentition, length inc. I to m. 3 55 mm. Upper dentition, length pm. 1 to m. 3 3 amm: Upper dentition, incisor 1, width 6} mm. Upper dentition, molar 1, length 6 mm. Upper dentition, molar, width 4; mm. Mandible, greatest length 82 mm. Lower dentition, length inc. I to m. 3 53. mm. Lower dentition, length pm. 1 to m. 3 32. nin; Lower dentition, molar 1, length 6} mm. Lower dentition, molar, width 3 mm. Third metacarpus, greatest length 28 mm. Pelvis, length front to back 83. mm. Femur, greatest length (computed) 93 mm. Femur, diameter of middle of shaft Qg mm. Tibia, greatest length go mm. Astragulus, length 14 mm. Astragulus, width It anm,; Calcaneum, length 253 mm, Metatarsus III, length 22. ommM. First phalanx of digit III, length I2 mm. Ungual palanx of digit III, length Qg mm. To make the similarity of Prosotherium with Pachy- rukhos clearer, I have restored Prosotherium, figure 40, from which it will be seen that this genus is also a hopping form with a plantigrade hind foot and a semidigitigrade front foot. In general it compares very closely with Pachy- rukhos, but the limbs are shorter and the grade of speciali- zation is not quite as high. It is, however, very evidently the ancestor of Pachyrukhos. ee —s PROSOTHERIUM GARZONI (‘9u0} JrePT) *9zZ]S peanqeu €/I—yuozie3 wnypray,OsoIg JO uows0jsIy ‘Ov “BLT .. data * » “yy 57 72 THE DESEADO FORMATION OF PATAGONIA Prosotherium triangulidens Ameghino P. triangulidens Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 427. P, robustum, Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 427. P, quartum Amegh., 1901, Bol. Acad. Nac. Cienc. Cordoba, t. 16, p. 371. This species is similar to P. garzoni except for size, the forms running about 12% larger, and being heavier built. In this same line the upper and lower molars are relatively wider and heavier. The top of the skull also is wider. | have drawn carefully the skull and dentition so that the detail can be seen from the figures. Beside triangulidens, Ameghino described P. robustum, which, as far as I can see, differs only in being about 5% larger, which is well within individual variation, so I have considered it as a synonym. ‘The same is the case with P. quartum, which Ameghino distinguishes as being about the size of P. robustum, and having lower pm. I present. The latter character we found also characteristic of P. garzoni, so only size remains and I do not consider less than 10% enough by itself to make a species. MEASUREMENTS Skull, length 110 mm. Upper dentition, length inc. I to m. 3 57. mm. Upper dentition, length pm. I to m. 3 25) mm: Upper dentition, incisor 1, width 8 mm. Upper dentition, molar 1, width 43 mm. Six specimens from Chico del Chubut Propachyrucos Ameghino Propachyrucos Amegh., 1897, Bol. Inst. Geog. Argen. t. 18, p. 425. The genus is based on lower jaws, in which the characters of the premolars, the molars and the first two incisors, resemble those of Pachyrukhos; but in this genus the third incisor, the canine, and the first premolar are retained and but little reduced. Ameghino has described two species, P. smithwoodwardi, and P. aequilatus. PROSOTHERIUM TRIANGULIDENS 73 Fig. 41. Top view of the skull, palatal view—natural size 74 THE DESEADO FORMATION OF PATAGONIA Propachyrucos smithwoodwardi Ameghino P. smithwoodwardi, Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 425. We did not find this species, but I reproduce Ameghino’s figure of it, natural size. The length Fig. 42. P. smithwoodwardi after Ameghino, right of the dentition from inc. mandible—natural size. A 5 I tom. 3 is 41 mm., height of mandible under m. 1 is T2 mm. Propachyrucos aequilatus Ameghino P. aequilatus, Amegh., 1901, Bol. Acad. Nac. Cienc. Cordoba, t. 16, p. 371. This species 1s based on the anterior lobe of each lower molar, being longer than the posterior. In size, molars 1 to 3 measure 24 mm.* Phanophilus Ameghino Panophilus, Amegh., 1903, Anal. Soc. Cienc., Argen., t. 56, p. 202. This genus is based on isolated upper molars, charac- terized as similar to Protypotherium, but having a pro- nounced median vertical column, instead of a groove on the external face of the upper molars, a character unique among typotheres. The position of the genus with this scant information is uncertain. One species is described, P., dorsatus. Phanophilus dorsatus Ameghino P. dorsatus, Amegh., loc. cit. p. 202. In our collection, two isolated upper molars of this un- usual form occur, corresponding in size and pattern to the one described by Ameghino. The external column, as *P. crassus has been described, (loc. cit., p. 425,) based on pm. 2 and 3, of larger size than either of the foregoing but I do not think that the genus can be determined on so small a fragment. — SS PHANOPHILUS 75 seen by fig. 42, is narrow and high. A single tooth measures 53 mm. from front to back, aay and 32 mm. in width. Specimen 3142 gen. and sp. ? This specimen is the mandible with the yer of miner milk dentition. The molars present suggest ee Prosotherium triangulidens, but inc. 3 and the canine are present, and the first two incisors are not enlarged, so it would seem to represent a genus which I have not been able to identify. Molar 1 is bilobed and similar to that of Prosotherium. Vhe deciduous premolars are all present, all ee ~ a) Fig. 44. Milk dentition, genus and species?—natural size. rooted, and all remarkable for their great antero-posterior elongation. Roots of the incisors and canine are present, that of the canine being the largest, and those of the incisors being about equal in size. This would suggest such a form as Protypotherium, were this genus represented in the Deseado beds. Interatheriidae The family is characterized by the incisors not being enlarged, by upper and lower premolars and molars being inflexed on both the inner and out sides, and by the inflated mastoid bulla being filled with cancellous tissue. The only genus referable to this family, from the Deseado beds, is Archaeophylus. Archaeophylus Ameghino Archaeophylus Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 423. The genus is based on a skull which preserved most of the upper dentition except the incisors, and which shows the characteristics of the family in their inception. 6 THE DESEADO FORMATION OF PATAGONIA SST Archaeophylus patrius Ameghino A. patrius Amegh., loc. cit. CA We found no specimen of this inter- ><. esting type, but I give a diagram of true after Ameghing, right Ameghino’s type, which shows the char- upper dentition—naturalsz*- acteristics of the species and genus. The length of the premolar-molar series is 27 mm. Eutrachytheridae Ameghino The family consists of larger forms than the other fami- lies, and is characterized by the upper molars having the inflexion bifurcated, so that the teeth are at least incipiently three-lobed. I would place in the family the genera, Eutrachytherus, Argyrohyrax, and Isopoedrium. Eutrachytherus Ameghino Trachytherus Amegh., 1889, Act. Acad. Nac. Cienc. Cordoba, t. VI, p. 918. Trachytherus Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 623. Eutrachytherus Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 429. This genus was first called Trachytherus, and when this was found to be preoccupied, changed to Eutrachytherus. Ameghino gives the dental formula as }>7>, but in my specimen which is a comparatively young individual, I find a small alveolus for the upper canine, which modifies the formula to 3743}. In the first upper dentition found, incisors 2 and 3 were represented by alveoli only, but our specimen shows these teeth, and we find that they have enamel only on the outer face, making this genus more specialized in this respect than any of the other typotheres. The upper molars have the deep inner inflexion bifurcated, which makes the tooth three-lobed, a character which grows more marked the older the individual is. The pre- maxillae are high and bring the snout well forward. The nasals are lacking, but the bounding bones show them to EUTRACHYTHERUS 77 have been unusually broad and flat. The maxilla extends up to the nasals, and bounds the lower border of the orbit, and projects backward in a heavy overhanging zygomatic process. The lachrymal bone is large externally, with a large but low lachrymal tubercle just below which is found the lachrymal duct, opening just in front of the margin of the orbit. The frontals are short and wide, extending outward over the orbit in a strong postorbital process which bounds half of the rear of the orbit. The parietals, meeting medianly, rise in a strong sagittal crest. Unfortunately the back part of the cranium is lacking. Fig. 46. E. spegazzinianus—1/2 natural size. From another specimen, which contained the brain cast, it is clear that the bulla was much inflated and hollow, and that there was an inflation in the upper part of the squa- mosum, as in Prosotherium, etc. One specimen with the facial portion badly weathered, but retaining enough to identify the species as E. spegas- zinianus, preserved the brain case, so that it could be prepared out. The most striking feature of this brain is its relatively large size, E. spegazzinianus being an animal about the size of a sheep, and the brain is as large as that of the sheep, which is in strong contrast to what would be ex- pected of an Oligocene form. Compared with the herbiv- 78 THE DESEADO FORMATION OF PATAGONIA orous Oligocene oreodont, Eucrotaphus, an animal of approximately the same size, this brain is half again as large in every way. 46-mm. 943) un, Premolar 4, width 63 mm. 64 mm. 58 mm. = 57 mm. Molar 1, length 55 mm. 55 mm. 57 mm. 55 mm. Molar 1, width 68 mm. 69 mm. 61 mm. 61 mm. Molar 2, length 685mm; -77mm?) “707mm. | 57-4nm- Molar 2, width 85 >mm. 93 mm, 75 mim, 68mm: Molar 3, length 75mm. 68 mm. 83 mm. 64 mm. Molar 3, width 86 mm. 87 mm. 82 mm. 88 mm. For the lower dentition, I give the figures which Ame- ghino records for his P. sorondoi, those given by Gaudry for his P. romeri, and the measurements of specimen No. 3207. The tushes in the lower jaw I would designate as incisors 2; because when the jaws are closed these diverge and their tips bite against the tips of the upper incisors 2. The first incisor seems to have been gradually lost and ¢ ea — ane Mh PYROTHERIUM SORONDOI 181 no space left for it in the front of the mandible, just as it was reduced and lost in the development from Moerithertum to Polymastodon or equivalent types. Fig. 114. Lower dentition—1/5 natural size; edges of teeth broken off in my specimen are indicated in outline. Lower DENTITION SPECIMEN AMEGHINO’S GAUDRY'S No. 3207 TYPE SPECIMEN Incisor 2 to molar 3, length 510 mm. 540 mm.* 415 mm.* Premolar 2 to molar 3, length 325 mm. 280 mm. 272 mm. Inc. 2, length above alveolus 133 mm. 188 mm.* 168 mm.* Inc. 2, antero-posterior diam. 55 mm. 60mm. 66 mm. Inc, 2, transverse diam. 40 mm. 36mm. 44 mm. Premolar 3, length 46 mm. 50 mm. 54 mm. Premolar 3, width 265mm. 3mm. 35) mm. Premolar 4, length 55 mm. 45 mm. 50 mm. Premolar 4, width 406 mm. 45 mm. 47 mm. Molar 1, length 65 mm. 50 mm. 51 mm. Molar 1, width 59 mm. 2mm. 7/5 mm. Molar 2, length 73 mm. 56 mm. 66 mm. Molar 2, width 73 mm. 63 mm. 66 mm. Molar 3, length : 69 mm. 67 mm. 71 mm. Molar 3, width 74mm. 66mm. 69 mm. Four cervical vertebrae were preserved with the skull number 3207, of which only about a third of the atlas is represented, but fortunately we found a complete atlas isolated and of the same size. The measurements for the atlas are taken from this separate specimen. While my skull, especially the teeth, seems to have been larger than the skull Gaudry described, the cervicals are a little smaller. I give the measurements of the cervicals which we found, comparing them with the figures given by Gaudry. * Figures taken from illustrations. 182 THE DESEADO FORMATION OF PATAGONIA SPECIMEN 3344 Atlas, antero-posterior length (without hypophysis) 120 mm. Atlas, greatest width 304 mm. Atlas, height 129 mm. SPECIMEN 3207 Axis, antero-posterior length 116 mm. Axis, greatest width 223 mm. Axis, width of odontoid process g6 mm. Axis, length of odontoid process 48 mm. Cervical 3, length of centrum antero-posterior 47 mm. Cervical 3, width of centrum 125 mm. Cervical 3, height of centrum 105 mim, Cervical 3, width of neural canal 75 mm. Cervical 3, height of neural canal 22 mm. Cervical 4, length of centrum antero-posterior 45 mm. Cervical 4, width of centrum 132 mm. Cervical 4, height of centrum 105 mm. GAUDRY’S SPECIMENS 140 365 140 124 248 88 44 45 145 100 mm. mm. mm, mm. mim. mm. nm. mm. nm. mm. The humerus is flattened from front to back in a striking manner, so that, seen from the side, it looks most slender; while in reality it is a very broad bone, nearly straight, and with marked rugosities for the attachment of the muscles. We found but one specimen of the humerus, an isolated bone a little smaller than that described by Gaudry. SPECIMEN GAUDRY’S No. 3218 SPECIMEN Humerus, total length 470 mm. Humerus, width at proximal end 232 mm. Humerus, width at middle of shaft 165 mm. Humerus, antero-posterior diam. of shaft 61 mm. Humerus, width across epicondyles 230 mm. We found neither the radius nor the ulna, but figures both, giving the following measurements. Radius, length 245 mm. Radius, proximal diam. 127 mm. UIna, length (calculated) 280 mm. Ulna, width of olecranon 140 mm. 500 232 mm. Inm., 170 mm. 240 mm. Gaudry See ee ee Ce eS we te i il i itd a a i tN tlh Ie me ee me PYROTHERIUM SORONDOI Fig. 115. Al., atlas; Ax., axis; C.3, third cervical; C.4, fourth cervical—1/5 natural size; apophysis of atlas is restored after Gaudry and the neural arch of cervical 4 is restored from the opposite side. Fig. 117. Anterior face of the humerus—1/5 nat- ural size. view. Fig. 116. Axis—1/5 natural size, front 184 THE DESEADO FORMATION OF PATAGONIA For the hind limb I give some of the figures which Gaudry gives accompanying his illustrations of the hind limb. Femur, length 630 mm, Femur, greatest proximal diameter 240 mm. Femur, distal diameter 170 mm. Tibia, length 370 mm. Tibia, greatest proximal diameter 164 mm. Tibia, greatest distal diameter 114 mm. Astragulus, antero-posterior diam. 123 mm. Astragulus, transverse diam. 114 mm. Astragulus, height 65 mm. 7 Cs - 2 e 5 # CHAPTER’ XIII RODENTIA WHILE all of small size, numerically the rodents make about a third of our collection, the number of genera and species being, however, relatively small. All are hystricomorphs with the pattern on the crowns of the teeth relatively simple. While the incisors are typically rodent-like, permanently growing teeth, the molars are all rooted, some being entirely brachydont, others begin- ning to show hypsodont features. So far as yet known, the rodents make their first appear- ance in South America, in this Deseado formation. Were they, as Ameghino thought, developed there from such a form as Propolymastodon or Promysops of the Casamayor formation? Or did they migrate into Patagonia from some other section? For the former proposition to be convincing to me, it would require more complete material of the forms suggested than now exists.* Other groups of hystricomorphs occur in the Theridomyidae of the European Oligocene, and from the Oligocene of the Fayum. fT Either the old world forms are descended from the South American forms, or vice-versa. The two African lower jaws are very much like those of Cephalomys, and my feeling is that the Patagonian forms are derived from some immigrant reaching that section before Deseado times. The Deseado genera are not widely different from each other, but it is evident that they are the representatives of at least two families, and my expectation is that other families will be found eventually to be already represented. * I have a lower jaw of Propolymastodon which, though not complete in front, gives me no suggestion that the incisor was rodent-like, and I am inclined to think that the incisor associated with the type of P. carlo-zitelli is a mistake. tOsborn, Bul. Amer. Mus. Nat. Hist., Vol. 24, p. 265. 186 THE DESEADO FORMATION OF PATAGONIA Our material does not permit the discussion of the skeleton or even of the skull as a whole, for the specimens occur only as isolated jaws, palates, or even as isolated teeth. In a few cases, the upper and lower dentitions are associated, but in no case was skeleton material clearly associated with the teeth. The remains look very much like such as are often found today in the western United States under a hawk’s nest or below the roosting place of owls. I think most of our specimens passed, before burial, through the stomach of birds or carnivors. Ameghino puts most of the forms in the family Cepha- lomidae, which he considers ancestral to I1ystricomorpha in general. I feel, however, that it is better to assign the Deseado genera to the families which have persisted until recent times, as Scott and Ameghino, in another place, have done. There are six living families, four of which Scott found already represented in the Santa Cruz. Two of these clearly may be continued back into the Deseado, the Erethizontidae, and the Chinchillidae, nothing as yet having been found to represent the Santa Cruz families Cavidae and Octodontidae. Chinchillidae In the Deseado, this family is represented by the genera Cephalomys, Scotamys, and possibly Litodontomys. Cepha- lomys is very abundant and seems to be ancestral to Pert- mys of the Santa Cruz; Scotamys is relatively rare but seems to be ancestral to Scotaeumys; while Litodontomys is also rare and as far as I can see without a successor. Cephalomys Ameghino Cephalomys Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p.-494. This is the common genus of the Deseado, over three- fourths of the specimens of rodents found belonging to one of its three species, Its dental characters mark it CEPHALOMYS 187 clearly. All the premolars and molars are rooted, though the crown is incipiently hypsodont, as much so as in any rodent of this period. The incisors are moderately large with the anterior face slightly convex, and the antero- posterior diameter comparing with the transverse diameter as 3 does to 2. The interval between the incisor and premolar 4 is moderate, indicating a short snout. Each lower molar consists of two transverse laminae separated from each other by an internal and an external infolding, both of which approach the median line but do not meet, a narrow, longitudinal bar separating the folds and connecting the anterior and posterior laminae. On the inner side, the posterior lamina has a furrow extending to the middle of the tooth, but only sinking into the crown about a fourth of its height, so that, with wear, it appears first as a bay, later as a pit, and finally disappears. In general it will be found only on molar 3, and may be wanting there on old individuals. On an unworn tooth, there occurs, on the inner side of the anterior lamina, a rudimentary pit corresponding to the one on the posterior lamina, but of much less depth, so that it is only occasion- ally seen, and that only on a very slightly worn tooth. The premolar differs from the foregoing in having a small median column on the anterior face of the anterior lamina. In three cases we found the deciduous fourth premolar (see fig. 119A), a complicated tooth, consisting primarily of three laminae in which furrows have developed until there are four folds or furrows on the internal side, sépa- rating five crests; while on the external side there are three furrows and four crests. Ameghino’s figure of this tooth in C. prosus has four laminae running clear across the tooth. I think the difference is due to his having an unworn decid- uous premolar whereas mine are all worn considerably. At first glance, the upper teeth appear strikingly differ- ent, resembling those of Perimys to which genus they are 188 THE DESEADO FORMATION OF PATAGONIA probably ancestral. Each molar consists of two laminae, separated by a deep internal fold which extends almost to the external margin. On little worn teeth each lamina shows, on the external side, a shallow furrow extending to about the middle of the tooth, but these furrows early become pits and then disappear with further wear, being preserved on not over a fourth of our specimens. The fourth upper premolar consists of two laminae, but in this case, the separating fold is on the external side and extends nearly to the internal margin, so that this tooth appears to be reversed in its position in the jaw. As in the molars, there is, on the external side of either lamina, a furrow, the one in the anterior lamina shallow and seldom seen, that in the posterior lamina deep and present in all but the most worn teeth. While the upper and lower molars appear so different they may be readily derived from such a tooth as the lower molar, as both have the two laminae and separating furrows in common. In the upper molars, however, the internal fold is prolonged until the external fold is merely indicated or lacking. On upper premolar 4, on the con- trary, it is the external fold which is prolonged. The fur- rows in the external portions of the laminae of the upper molars correspond to those on the internal portions of the same laminae of the lower teeth, reversed, as is typical of all teeth. Ameghino distinguished three species of Cephalomys, which are based primarily on size, the other characters which he gave being inconstant. We found these three and no others. UPPER PM.4 LOWER PM. 4 TO M. 3 TO M. 3 C. arcidens 13-14 mm. 14-15 mm. C. plexus 9.5 mm, 10.5 mm. C. prosus 8.5 mm. 9.5 mm, Seema ai gaa ne ner i, Sg a UR i ea! ath al aa ay At aI EO Se CEPHALOMYS ARCIDENS 189 Cephalomys arcidens Ameghino C. arcidens Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 494. This, the type species, is by far the commonest of the rodents, in fact of all the species in the Deseado, and we found forty-seven specimens on the Chico del Chubut River, west of Puerto Visser. In the species there is con- siderable variation in size for a rodent, but as there are intermediate specimens all the way porees the extremes, and as the variation is mostly in the sizeof the fourth premolar, it does not seem proper to separ- ate the material into more than one species. In general, the form has relatively plump teeth, relatively heav- ier and thicker than in the other species. Usually the fourth premolar is but little larger than the molars, Fig. 119. Left lower premolar, molar series; 4, decodu- Coline . ous premolar 4; B, a little worn mola 1; C, series about but, In this character, half worn down; a.l., anterior lamins; ).l., posterior A nS lamina; i.f., internal fold; ets eel fold; p.g., fur- there 1S considerable row in posterior lamina; x 4,/ : : - variation. The fol- lowing measurements give the range of size on the upper Fig. 118. Right upper premolar, molar series x 4/1. jaws: SPECIMEN SPECIMEN AMEGHINO'S 3109 3099 TYPE A SMALL A LARGE INDIVIDUAL INDIVIDUAL Upper premolar 4 to m. 3 12.5 mm. L5. mm: L355 walt. Upper premolar 4, length 3.5 mm. 4.5 mm. Each molar, length Be anim: 39 4.1m’ Each molar, width 2.75mm. 3. mm. 190 THE DESEADO FORMATION OF PATAGONIA The lower jaw is low, heavy and rather short, the posterior part of the ramus being very thin, while the portion carrying the teeth is thick and heavy. A strong ridge extends along the inner side from just behind molar 3 to the base of the symphysis. As in the upper dentition, there are smaller and larger forms. SPECIMEN SPECIMEN AMEGHINO’S 3089 3058 TYPE A SMALL A LARGE INDIVIDUAL INDIVIDUAL Lower premolar 4 to m. 3 14 mm, 15 mm, 14.5 mm. Lower incisor I to pm. 4 7 Imm, 9g mm. 7.8 mm. Height of mandible under pm. 4 rete Bilt y 8 mm. 7. nim, Length of deciduous pm. 4 5.5 mm. Cephalomys plexus Ameghino C. plexus Amegh., 1897, Bol Inst. Geog. Argen., t. 18, p. 494. In general, this species is similar to the foregoing, but is smaller in size and slenderer in proportions. Both the upper and lower fourth premolar tend to be considerably larger than the molars. The species was not nearly as abundant as C. Hies7p Rene palinte dione Toe ens, Occurring but sixteen UE ater ead aie ACUTIES: Ul OU GOHec tons Fig. 121. Left mandible, external side, x 4/t. MEASUREMENTS Upper dentition, pm. 4 to m. 3 Upper dentition, pm. 4, length Upper dentition, each molar length Upper dentition, each molar width CEPHALOMYS. PLEXUS I9I SPECIMEN AMEGHINO'S 3091 TYPE Q. mm. 9.5 mm. 2.75 mm. Zot amin: 2.25 mm: The lower jaw is slender, the incisor being relatively both smaller and slenderer than in C. arcidens; the back part of the ramus light and thin, the coronoid process being a tiny spur, and the articular condyle of small size, and on a level with the teeth. MEASUREMENTS Lower dentition, pm. 4 to m. 3 Lower dentition, in. I to pm. 4 Lower dentition, pm. 4, length Lower dentition, each molar, length Lower dentition, each molar, width Height of mandible under pm. 4 ext. Fig. 122. C. plexus, left lower premolar, molar series; A, of young individual; B, of old individual; int., internal side; ext., external side, x4/I. SPECIMEN AMEGHINO’S 3005 TYPE 10 mm. 10.5 mm. 6). mm 6.5 mm. 3- Be 2 5 Fig. 123. C. prosus, left upper premolar, molar series, x 4/1. tee Fig. 124. C. prosus, premolar 4 and molar 2, x 4/1. Cephalomys prosus Ameghino C. prosus Amegh., 1902, Bol. Acad. Nac. Cienc. Cordoba, t. 17, p. 37. This is the tiniest species of the genus, and least fre- quently found, probably because on account of the small size it was more frequently destroyed before burial, and also because it is hard to find such tiny specimens; so that 192 THE DESEADO FORMATION OF PATAGONIA the sixteen which we found would hardly represent the real proportion of the species in the fauna. The jaws are not only small, but also slender and deli- cately built, with the premolar about the same size or slightly larger than the molars. The drawings represent the proportions accurately so I will give but a few measure- ments. SPECIMEN AMEGHINO’S 3009 TYPE Upper premolar 4 to molar 3 8.5 mm. Lower premolar 4 to molar 3 9.5 mm. Scotamys gen. nov. A lower jaw, with premolar 4 and molars 1 and 2, from the Deseado beds on the Chico del Chubut River, west of Puerto Visser, indicates a genus of hystricomorph rodents not previously reported. The lower molars suggest those of Perimys, but premolar 4 is similar to that of Scotaeumys from the Santa Cruz. Scotamys differs, however, from Scotaeumys, in that its molars do not have the third lobe found in the Santa Cruz genus. I have, therefore, made a new genus which appears to be ancestral to Scotaeumys. Scotamys antiquus sp. nov. This, the type species of the above genus, is based on specimen 3063, a lower jaw with the incisor, premolar 4 and the first two molars. The incisor is fairly large and heavy, the anterior face slightly convex, and the anterio- posterior diameter greater than the transverse diameter. Premolar 4 has a deep external fold, dividing the crown into an anterior and posterior lamina, the former being then subdivided by another external fold, making the tooth three-lobed. Just internal to the median fold is a tiny pit, apparently the last vestige of an internal fold. Each molar consists Fig. 125. Lower premolar 4 —molar 2, x 4/1. SCOTAMYS 193 of two laminae separated by a deep external fold, around the inner end of which the laminae are connected by a narrow bar. In the present condition of wear there is no indication of secondary furrows. The premolar is smaller than the molars. MEASUREMENTS SPECIMEN 3063 Lower dentition, in. I to pm. 4 8 mm, Lower dentition, premolar 4 length x mm., width 2.5 mm Lower dentition, molar 1 length 2.5 mm., width 2.5 mm Lower dentition, molar 2, length 2.75 mm., width 3 mm Height of mandible under pm. 4 acwew itis Fig. 126. Left mandible external side, x 4/1. Litodontomys gen. nov. One set of lower teeth found by the Amherst party shows a simplicity of pattern found in no other genus of South America; and this is, therefore, named Litodontomys. The teeth are brachydont, the premolar and the molars each being divided into two laminae by an external and an internal fold, the distinctive generic feature being in that this fold is narrowest at the margin of the tooth and expands internally. In connection with the expanded folds, the ends of the laminae are curved toward each other, so that in a worn specimen they would meet on the margins of the tooth, and leave the folds to appear as pits. No indication of a furrow is evident on either lamina. 13 194 THE DESEADO FORMATION OF PATAGONIA Litodontomys chubutensis sp. nov. The type is number 3086 of the Amherst collection, from the Deseado beds on the Chico del Chubut River, west of Puerto Visser, and consists of the lower premolar-molar series. Premolar 4 is elongated, the Sata Ceh ee crea a eeeran tenon laminae veingecOnsider- ably longer than it is wide, whereas the laminae of the other teeth are wider than they are long. The following measurements with the figure give the specific details. Lower dentition, premolar 4, to molar 3 10.5 mm. Lower dentition, premolar 4, length Gees cine Lower dentition, molar 1, length me tri. Lower dentition, molar 2, length 2.5 mm. Lower dentition, molar 3, length 2.5 mm. Lower dentition, width of molars Pie nin iaale ERETHIZONTIDAE Asteromys Ameghino Asteromys Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 495. The genus contains small forms, with brachydont teeth. The upper molars consist of two laminae, separated by an internal and an external fold, and each lamina having, on the internal half, a deep furrow, which is but little shallower than the median fold; so that the outer side shows three furrows, folds, or pits, more or less completely separating four lobes; while on the inner side of the tooth there are but two lobes. On the lower teeth the external median fold is deep, while the internal median fold is shallower, usually appearing as a pit. Both the anterior and posterior laminae are subdivided by wide internal furrows which extend to the median line. These characters associate the genus with Acaremys of the Santa Cruz, from which genus it is not easy to separate ASTEROMYS 195 Asteromys; but as we know only the teeth from the Deseado beds, it is probable that, when the skull is found, larger differences will be recognized. Asteromys appears to be the direct ancestor to Acaremys. The species are all tiny, the following three being dis- tinguished by Ameghino. LENGTH OF LOWER MoLAR SERIES A. punctus (Bol. Inst. Geog. Argen., 1897, t. 18, p. 495) I2 mm. A. annectens (Bol. Acad. Nac. Cienc. Cordoba, 1902, t. 17, p. 37) II mm. A. prospicuus (Bol. Inst. Geog. Argen., 1897, t. 18, p. 495) each molar 1.6 to 1.8 mm. Of these three we found only the last. Asteromys prospicuus Ameghino A. prospicuus Amegh. loc. cit. above. The species is rare, only three specimens turning up in our collections. The upper molars are as described in Fig. 128. Right upper premolar 4— : Fig. 129. Left lower molar 3, x 4/1. molar 2, x 4/1. the generic discussion, but premolar 4 is simpler than the molars, the posterior lamina being small and without any sort of furrow. In the upper molars the anterior lamina is larger than the posterior, and the anterior furrow wider than the posterior. The following measurements, with the figures, indicate the character of the species. “I nn =| = Upper dentition, premolar 4 to molar 3 Upper dentition, premolar 4, length Upper dentition, each molar, length Upper dentition, each molar, width Lower dentition, molar 2, length Lower dentition, molar 2, width m WwW tO NH W CO ios) 3 3 ~1 os an nN 3 B 196 THE DESEADO FORMATION OF PATAGONIA Eosteiromys Ameghino Eosteiromys Amegh., 1902, Bol. Acad. Nac. Cienc., Cordoba, t. 17, p. 110. The genus was established by Ameghino for forms similar to Steiromys of the Santa Cruz, but antedating that time. I confess I can see but little difference between Stezromys and LEosteironys, but the latter is as yet known only from isolated teeth and as in general it would be expected that there should be a generic difference, we may let this genus stand representing rather a prophecy than the facts as yet known. The upper teeth are brachydont, the crown being on the same general plan as in the foregoing genus, 7. e., it is divided into an anterior and posterior lamina by a deep external median fold and by a shorter oblique internal me- dian fold. The anterior lamina is subdivided by two ex- ternal furrows, a lesser anterior and a larger posterior; while the posterior lamna is subdivided by a single external furrow; so that this tooth has four folds, furrows, or pits on the external side separating five lobes; while on the inner side there is but the one oblique fold separating two lobes. Eosteiromys medianus Ameghino ? E. medianus Amegh., 1902, Anal. Mus. Nac. Buenos Aires, ser. 3, t. 2, p. 129. The genus is based on a single, though entirely characteristic, upper molar. We found just one tooth of the species, also an upper molar. It is described above, under the genus. The measurements are: Upper Hig. 130, Went veer inolar2)\-lenethea. mur, width: 5 im CHAPTER XIV EDENTATA THE scarcity of edentates in the Deseado beds is in striking contrast to their abundance in the Santa Cruz formation. Whereas in this latter horizon over half of the finds are edentates, in the Deseado only eight per cent. of the total collection belong to this group, and this is doubt- less a larger proportion than these animals represented in the fauna; for the hundreds of small plates in a carapace, when scattered greatly, increase the chance that some part of an individual will be found, and most of the eight per cent. of finds are single plates. Most of the plates found represent armadilloes, our collection containing but one plate of a glyptodont, and no gravigrades. Ameghino’s collections present about the same relations, but in the repeated trips he found a few more traces of glyptodons and a very few gravigrades. This scarcity of edentates can not be taken to mean that they were not developed, for they are a peculiarly South American group, and as they were developing somewhere into their great complexity, | take it to mean that the climatic conditions were unfavorable in this particular section. As noted above, all previous finds have been isolated plates. We were fortunate enough to find one specimen consisting of a carapace with ten rows of movable plates in place, and parts of four rows of the pelvic buckler to- gether with over fifty isolated plates. A second specimen had some fifty associated plates which were mostly from the pelvic buckler. Dasypoda The representatives of this group are so poorly known in the Deseado beds that Ameghino has, in general, used 198 THE DESEADO FORMATION OF PATAGONIA the generic names of the Santa Cruz for their description, and, so far as known, they are little differentiated from those genera. There is as yet no material which shows the association of skeletal parts with the carapaces. ‘There- fore, in this paper, comparisons are made wholly on the carapace, with the expectation that the skeleton, when found, will correspond. The Deseado species are but little less specialized than the Santa Cruz, the carapace consisting of movable over- lapping bands of plates both in the anterior and body portions, while over the pelvic region the plates are fixed, do not overlap, and form a pelvic buckler. Ameghino has described a considerable number of genera based on isolated plates, to which I refer later. The chief genera which occur in these beds are also found in the Santa Cruz, and the distinguishing features are as follows: CEPHALIC SHIELD | MOVABLE PLATES | PELVIC BUCKLER | ORNAMENTATION Proeutatus |Plates thin, coarsely|Plates thick, } over-|8 + probably 10) ‘‘Flask”’ figure | pitted lapped rows | | Prozaedius (Plates thin, finely'14 bands, thin, 1/8 rows 3. long ridges, | pitted overlapped | median ridge nar- | | row Stenotatus Plates thick,coarsely| Plates thick and|11i rows ‘3 long ridges, all pitted | wide | subequal rae jee —| eae pl Proeuphractus i overlapped No buckler | Peltephilus 19 or 21 Plates 2 or 4;Wide and thin 2~4! Buckler Large shallow pits horns | wide pits Proeutatus Ameghino Eutatus Amegh., in part, 1887, Bol. Mus. La Plata, t. I, p. 25. Proeutatus Amegh., 1891, Revista Argén, d. Hist. Nat., t. 1, p. 327. Thoracotherium Mercetat, 1891, Revista Mus. La Plata, t. 2, p. 42. FEutatus Lydekker, in part, 1894, Anal. Mus. La Plata, t. 3, p. 62. Proeutatus Scott, 1903-5, Reports Princeton Patagonian Exp., vol. 5, p. 40. This is the most frequently occurring genus in the Deseado, but is as yet represented only by isolated plates. PROEUTATUS 199 The genus is distinguished by thick, relatively long and narrow, movable plates, cach overlapped by about a third of its length. The plates of the pelvic buckler are shorter and thicker, the exposed surface of each being ornamented by a figure compared by Ameghino to a flask {see fig. 131), which figure is more distinct on the rear, fading away toward the front. On the plates of the pelvic buckler this figure is more accentuated, and from it, on either side, radiate two furrows dividing the surface into several (4 to 5) areas. The entire surface of each plate is irregularly punctate. ‘ Proeutatus lagenaformis Ameghino P. sp? Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 660. P. lagenaformis Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 507. On the Chico del Chubut River, west of Puerto Visser, we found nine specimens of this species, all fragmentary, though one consists of over fifty more or less broken plates, mostly from the pelvic buckler. This is the only species of the genus from the Deseado, and corresponds to the description above. A movable + plate generally measures abaut 28 Fig. 131. 4, movable plate; B and mm. long by 10 mm. wide, and has tfaldee 7™ Pe Puckler—nate four large piliferous pits on the posterior margin. A plate of the pelvic buckler varies greatly in size, but is always thick and has two to eight piliferous holes on the posterior margin. i Fig. 149. Right femur, back view— 228 THE DESEADO FORMATION OF PATAGONIA the contour of the shaft. Between these ridges there is a wide shallow furrow which also loses itself above in the con- vex surface of the shaft. MEASUREMENTS Femur, least diam. of the shaft 58 mm. Femur, diameter across the condules 148 mm. Physornis sp.? Two phalanges of a size too small to belong to the above species represent a second smaller bird of this type, about equal in size to Phororhacus infiatus. I give a figure of one toe but would wait for more typical material before establishing a species. . Fig; 151. Loxornis Fig. 150. Proximal clivus, lower end = of phalanx of Physornis tibio-tarsus, after Ame- sp?-——natural size. vhino—-natural size. Loxornis Ameghino Loxornis Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 595. Another group of bones, which we found with consider- able frequency, have the same features as Pelecyornis of the Santa Cruz. Ameghino has described but the lower end of a tibio-tarsus which can be associated with these bones and to it gave the name Loxornis. 1 can not find iA SW, te Se oa hal 3 Pe : : | ; . et = & + . 3 * é = # v4 LOXORNIS 229 much variation from Pelecyornis except that the coracoid is considerably shorter and wider, and there is a slight variation in the lower end of the tibio-tarsus. “These then are the bases of the generic name. Loxornis clivus Ameghino L. clivus Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 595. Under this name Ameghino has described the lower end of a tibio-tarsus, a figure of which I reproduce here. This is of a size to complete the tibio-tarsus which we found, lacking the lower end, and agrees in size with the other Fig. 152. Humerus— Fig. 153. Sternum, thin parts lack- Fig. 154. Coracoid— 1/2 natural size. ing—1/2 natural size. 1/2 natural size. bones which we found, so that I shall describe my material under this name. The species is in size comparable to Pelecyornis tubulatus with which it agrees closely. We found the upper four-fifths of a tibio-tarsus, associa- ted with part of the fibula, the sternum, the humerus, and the coracoid; a second specimen consisting of a complete tarso-metatarsus, and fragments of the pelvis, vertebrae and wing bones; a third specimen consisting of part of the tibio-tarsus, and various fragments; a fourth consisting of a femur, and lastly two toes; all evidently representing one species, which in most respects is almost identical with Pelecyornis tubulatus. These all came from the Chico del Chubut, west of Puerto Visser. 230 THE DESEADO FORMATION OF PATAGONIA The humerus has a large head but is considerably flat- tened at the proximal end. ‘The internal side is deeply excavated, the shaft is slender and light as though the wing were quite reduced, though not so much as in Pelecyornis and not nearly as much as in Phorerhacus. The sternum had a moderate keel but both this and body of the bone are very thin, so much so, that in my specimen, much is broken away, giving the figure the appearance of the bone being fenestrated, which was not the case. In general the sternum is similar to Pelecyornis. The coracoid is a decidedly stout bone, with a’ wide dis- tal end for articulation of the sternum. The proximal end has a long articular facet for the scapula. This bone is heavier than the corresponding one in Pelecyornis. The femur has a small rounded head on a short neck, the articular surface spreading over the entire proximal end of the bone. Thus the trochanter is abbreviated and does not rise above the top of the head. The shaft is of considerable length and fairly heavy. The tibio-tarsus has a wide flaring end to receive the articulation of the femur. The bone is very long as in Pelecyornis. On the external side is a long ridge along which the fibula was attached by cartilage or by ligaments, but was not fused to the tibio-tarsus. The shaft is approxt- mately cylindrical in section and fairly heavy. ‘The distal end is missing, but if I have associated correctly the speci- men figured by Ameghino, the condyles are flattened, the inner being the flatter, and the outer rising in a narrow margin. Figure 157 shows a fibula which would have occupied the position indicated along the side of the tibio-tarsus and corresponds entirely with the same bone in Pelecyornis. The tarso-metatarsus is long and slender, almost exactly the counterpart of the same bone in Pelecyornis. ‘The bone has a triangular upper end, with two shallow articular ey Re spieieae cen 4 LOXORNIS CLIVUS 231 | concavities, separated by a median spine. The shaft is | rectangular in cross section, has a shallow depression on : the anterior face extending from the upper end to below | the middle of the shaft; while on the posterior surface is a | | | eee 4 : Fig. 157. Fibula—1/2 natural size; outline from impression in ma- trix. Fig. 155. Femur—1/2 natural size. Fig. 156. Tibio-tarsus —t/2 natural size; fib- Fig. 158. Tarso-met- ula indicated in out- atarsus, front view— ine. 1/2 natural size. similar furrow, which is however bounded by a higher ridge on the external margin. The distal articular condyles are almost bilaterally symmetrical, the middle one being about half again as large as the two lateral ones. Just above the cleft between the condyles for digits III and IV there is a moderate sized perforation. 232 THE DESEADO FORMATION OF PATAGONIA Of the phalanges, [ have two unguals which are narrow curved claws. These were not found in association with any of the foregoing bones, but correspond in size and general character to those of Pelecyornis, and so I consider them as belonging to this genus and species. Fig. 160. Femur of unknown bird—natural ee . 1 ms 2 ” Fig. 159. Ungual pha size; special No. 3217. lanx—1/2 natural size. Ameghino has suggested that the genus was related to ducks, but with the more complete material it seems, in general build, much closer to the aberrant land birds of the Tertiary of South America, Pelecyornis and Phororhacus; and I am not in position to say what their derivation may have been. Beside the above species there are several more or less complete but isolated bones indicating the presence of other and much smaller birds. I figure such a femur natural size. i ee ey ee ee a ia tie ait Se ee ee ye en ee wT se eee) eee he ig ee oe set aM a eg | — Sg ee ee we tc Same ¥ F. FP — eee Se — * 7 : oy : i BS ot ¥ aa .. x at ; F : : a ; x ; ; = “2 A = Ber p - 7 : z . ; : : ¥ ? x i Ge : 7 ar : : “ 7 4 7 * 7 4 » . } , : : : 4 - ‘ : : t u > - : 4 : ; ce ed, Feehan | so 2 gow, Sry Hay een . 3 g a a: ; 4 QE Loomis, Frederic Brewster 752 The Deseado formation of P3L6 Patagonia PLEASE DO NOT REMOVE CARDS OR SLIPS FROM THIS POCKET UNIVERSITY OF TORONTO LIBRARY PGicH asta tees ae 7 oe fete fet Eras canister este ivecatin at tee Serer ast ti iat 4 ast os ists Tate abi