FIELDIANA Geology NEW SERIES, NO. 21 Protoptychus hatcheri Scott, 1895 The Mammalian Faunas of the Washakie Formation, Eocene Age, of Southern Wyoming. Part II. The Adobetown Member, Middle Division (= Washakie B), Twka/2 (In Part) William D. Turnbull January 31, 1991 Publication 1421 PUBLISHED BY FIELD MUSEUM OF NATURAL HISTORY Information for Contributors to Fieldiana General: Fieldiana is primarily a journal for Field Museum staff members and research associates, although manuscripts from nonaffiliated authors may be considered as space permits. The Journal carries a page charge of $65.00 per printed page or fraction thereof. Payment of at least 50% of page charges qualifies a paper for expedited processing, which reduces the publication time. Contributions from staff, research associates, and invited authors will be considered for publication regardless of ability to pay page charges, however, the full charge is mandatory for nonaffiliated authors of unsolicited manuscripts. 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Author-generated changes in page proofs can only be made if the author agrees in advance to pay for them. THIS PUBLICATION IS PRINTED ON ACID-FREE PAPER. FIELDIANA Geology NEWSERIES.NO. 21 Protoptychus hatcheri Scott, 1895 The Mammalian Faunas of the Washakie Formation, Eocene Age, of Southern Wyoming, Part II. The Adobetown Member, Middle Division (= Washakie B), Twka/2 (In Part) William D. Turnbull Curator Emeritus, Fossil Mammals Department of Geology Field Museum of Natural History Chicago. Illinois 60605-2496 Accepted May 18, 1989 Published January 31, 1991 Publication 1421 PUBLISHED BY HELD MUSEUM OF NATURAL HISTORY © 1 99 1 Field Museum of Natural History ISSN 0096-2651 PRINTED IN THE UNITED STATES OF AMERICA Table of Contents List of Tables Abstract/Dedication 1 Introduction 1 Geology, Stratigraphy, and Localities . . 2 Materials 2 Descriptions 7 Skull and Bulla 7 Mandibles 14 Dentition 15 Postcranial Skeleton 18 Discussion 28 Conclusions 29 Acknowledgments 31 Literature Cited 31 Appenddc 32 6. Measurements of some features of the skull and jaws of various specimens of Protoptychus 12 Protoptychus upper cheektooth measure- ments 16 Protoptychus hatcheri lower cheektooth measurements 18 Cross-section measurements of incisors of Protoptychus hatcheri 20 Measurements of limb and girdle ele- ments of Protoptychus and some modern ricochetal rodents 24 Status of vertebrae and ribs of specimens of Protoptychus 27 List of Illustrations 1 . Eocene sediments of the Uinta and Washakie Basins, with Protoptychus lev- els noted 3 2. Views of Field Museum's Protoptychus locality that yielded most specimens ... 4 3. First Field Museum Protoptychus skele- ton 6 4. Second Field Museum Protoptychus skeleton 6 5. Carnegie Museum specimen of Protop- tychus 8 6. Type specimens of Protoptychus smithi Wilson and P. hatcheri Scott, with views of additional P. hatcheri 10 7. Protoptychus hatcheri, left lower jaw ... 15 8. Series of maxillary specimens of Protop- tychus hatcheri 21 9. Series of mandibles of Protoptychus hatcheri 22 10. Bivariate graphs of teeth of Protopty- chus hatcheri 23 1 1 . Limb and tail proportions in Protopty- chus and comparative species 29 1 2. Scheme of protrogomorphous condition for primitive rodents and phylogenetic scheme for Protoptychus 30 Protoptychus hatcheri Scott, 1895 The Mammalian Faunas of the Washakie Formation, Eocene Age, of Southern Wyoming. Part II. The Adobetown Member, Middle Division (= Washakie B), Twka/2 (In Part) Abstract /Dedication This report was originally intended for the fest- schrift honoring Philip Hershkovitz (Patterson & Timm, 1987). I was unable to complete it in time for inclusion in that volume and subsequent events have caused further delays. It deals with a highly specialized Eocene rodent that is of particular in- terest paleontologically, anatomically, and ecolog- ically. Intriguing, partially unresolved, phyloge- netic considerations concerning its relationships are discussed. These suggest broader implications for rodent systematics. I expand upon the prior descriptions of the skull and teeth, and describe for the first time details of skeletal morphology of this jerboa-like species, Protoptychus hatcheri Scott, 1895, with its en- larged elongated hind limbs and greatly expanded auditory bullae, features that so aptly characterize these ricochetal creatures. The descriptions are based upon specimens recovered, mostly from a single locality, within the Washakie Basin of southwestern Wyoming. Protoptychus lived in a subtropical environment during the late Middle Eocene in Wyoming and Utah. The associated faunal and floral elements included alligators; softshelled turtles; rhinocer- oses; a variety of insectivores, primates, and ro- dents; and palm trees. All have living members that usually are limited to the tropics or subtropics. Some other faunal associates such as gar fish, uin- tatheres, titanotheres, tillodonts, taeniodonts, achaenodonts, and hyopsodonts were probably similarly circumscribed, but the evidence for this is more tenuous; from wherever they are known, they are associated with the same or similar suites of tropically restricted forms. Stratigraphy, regional geology, and lithology give evidence of abundant stream channel and flood- plain deposits. Doubtless, the main drainages sup- ported some sort of riverine forests, and perhaps these extended along the borders of the intermit- tent ponds or central lake(s). But the presence of the jerboa-like Protoptychus suggests that the broad divides between the narrow, but lush, forested cen- tripetal drainages of the Basin were probably arid, because today all such highly specialized living creatures occupy arid or semiarid environments. Phil, with his wide appreciation of ecological and environmental relationships of the modern faunas and with his extensive works on rodents, will be as intrigued by this animal as anyone. I therefore dedicate this account to him, for he is an esteemed and helpful friend and colleague. We have shared many, often lengthy and always stim- ulating, discussions of dental morphology and evolution, and sometimes these strayed into far more wide-ranging topics. For all of this, I am pleased to honor him in this manner. Introduction This study reports on an extinct and until now poorly known rodent genus that is remarkably spe- cialized for hopping and turning with ricochetal movements in a manner very like that seen in TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 modern jerboas, if we may infer the habits of the fossil form from the known locomotion and anat- omy of its reasonable living analogues. In fact, in as much as the genus, Protoptychus, is the earliest form to attain such a specialization, all later ones must be considered as being convergent upon it, if not actually descendant from it. The two most striking specialized features correlated with this distinctive way of life are greatly lengthened hind limbs and tremendously enlarged auditory bullae. That great elongation of hind limbs should be cor- related with specialized hopping is intuitively rea- sonable, but that such extreme bullar specializa- tions, which are only partially understood, should be, is far less clear. Geology, Stratigraphy, and Localities Protoptychus is known only from Middle Eo- cene, Uintan deposits of the Uinta and Washakie Basins (Berggren et al., 1985) from stratigraphic units that on the basis of faunal and stratigraphic correlations appear to be nearly contemporaneous. Krishtalka et al. (1987) reviewed the earlier works that paved the way for the modern stratigraphic interpretations and gave details for both the cor- relations and the bases upon which they stand. A modified segment of their correlation chart is giv- en (fig. 1). It represents slightly more than the 15 my of Eocene time, and shows where within the late Middle Eocene the Protoptychus fossils occur. All but two of the recognized specimens of Pro- toptychus from the Washakie Formation are from a single locality, FM-8-57-WDT, located in W'/2, SE'/4, Sec. 13, T15N, R98W, Sweetwater County, Wyoming (USGS Kinney Spring, Wyoming Quad- rangle, 7.5 minute series). The locality is also shown on the map of the NW Quadrant of the Washakie Basin (Turnbull, 1978, pi. 2, p. 589), where it is designated as being in the Slfr of that section. It is within the Adobetown Member, in its middle di- vision, Twka/2, of Roehler (1973) and Turnbull (1978). This middle portion of the member cor- responds to the Upper Washakie (= Washakie B) of Granger (1909) and others. The bed itself is near to the level of Roehler's Bed 640, although there is some uncertainty about the precise cor- relations of the beds and levels in this portion of the section. The precise locality is one of several subdivi- sions of the above-designated general locality called the Protoptychus locality; it is shown in Figure 2. It lies near the base of the Protoptychus sandstone unit, which is more than 30 ft (9 m) thick, lightly indurated, and crossbedded throughout. Capping the unit is a more heavily indurated subdivision about 6 in. (15 cm) thick that forms the lip of the rim in the area and protrudes to the east out from under the dune cover at the track. All of the beds in this area have an E-SE dip (about E 1 20 degrees) of variable inclination near to but not exceeding 7.5 degrees. The Protoptychus locality itself, which includes several natural alcoves on each side of the one that produced the two partial skeletons, has produced several hundred identifiable fragments of various small mammals as well as some reptile and bird remains. The associated mammals include mar- supials, insectivores, primates, carnivores, con- dylarths, perissodactyls, and rodents (both Pro- toptychus and several other taxa). Most of the fossils consist of scattered and broken pieces that either had weathered out, or were removed, from thin lenticular stringers of pebbles, small bones, or bone chips and teeth that lay along certain of the bed- ding planes of the otherwise nearly barren sand- stone unit. The two nearly complete, articulated specimens of Protoptychus that constitute the heart of this discussion (figs. 3, 4) are exceptions in that they were not a part of any of the bonebearing lenses, but lay several centimeters below one of the more extensive of these stringers. The two an- imals may have died in their burrows, although we found no traces of burrow infillings to support this idea, or they may by chance have been buried and preserved before scavengers got to them. Most of the missing parts were lost to weathering during exposure, but some of the skeletal elements may have been scavenged shortly post mortem (left ma- nus of PM 8018, part of the rear quarters of PM 39371). Materials Order Rodentia Suborder Protrogomorpha Family Protoptychidae Protoptychus Scott, 1895 P. hatcher i Scott, 1895 (including P. smithi Wil- son, 1937). The prime specimens identified as P. hatcheri from locality FM-8-57-WDT are PM 8018 (fig. 3) FIELDIANA: GEOLOGY Il N.A.L.M.A UINTA BASIN WASHAKIE BASIN 40- DUCHESNEAN UINTAN 45 BRIDGERIAN 50- WASATCHIAN STARR FLAT MEM. LAPOINT MEM *•£ ^^MYTON MEM. GREEN RIVER FM. COLTON FM./ WASATCH FM./ DEBEQUE FM. TYPE PROTOPTYCHUS HATCHERI PM80I8-PM3937I AND ALL OTHER FMNH SPECIMENS TYPE P SMITH1 AND CM9386 CLARKFORKIAN Fio. 1. Correlation chart for the Eocene sediments of the Uinta and Washakie Basins, with approximate levels of all of the known Protoptychus specimens indicated. The type of P. hatcheri is from Kennedy's hole, Upper Uinta B. Most of the others (star) are from one locality at the base of the Protoptychus SS unit, Bed 640, of the middle division (Twka/2) of the Adobetown Member, i.e., within the Washakie B of other workers. and PM 39371 (fag. 4). Both are nearly complete skeletons. The first was discovered in 1959 (field number W-7-59) lying on its right side as shown in the figure. The then exposed portions (the few bleached white areas of bone) suggested that pos- sibly there were two animals present, to judge by the disproportionate sizes of the exposed limb bones. Preparation proved otherwise, and the large rear quarters proved to be connected to the small and delicate ribs, front limbs, and skull. Unknown to us at the time, there was another skeleton within three feet of the first and in a similar position, also on its right side, but more nearly on its back then the other; it lay unexposed and undetected. It be- came exposed through weathering a decade later and was collected (field number T-69-3). Repeated collecting at this locality has produced 69 specimens referred to this taxon; mostly these are maxillary or mandibular remains. All are listed in the Appendix. The sample is large enough to provide an assessment of dental detail, variation, and wear. TURNBULL: PROTOPTYCHUS HATCHER! SCOTT, 1895 *. " ' '*"*"- ' Fig. 2. Three views of the part of the Field Museum's Protoptychus locality (FM-8-57-WDT) that yielded most of the specimens. The fossils were found eroding out of the base of the exposed part of the Protoptychus sandstone where the man is seen prospecting. In all there are five natural alcoves eroded into the bluff; the three richest ones are numbered on the photo in A. The other less productive alcoves lie to the left and right of those shown. A, Overview, looking south over the intervening wash at the three main alcoves, seen from the top of an erosional remnant ridge that protrudes to the east into the erosional badlands from the edge of the Adobetown Rim (see Turnbull, 1978, pp. 589-590, 594). B, View looking southeast while standing on the productive level of the Protop- tychus sandstone within alcove #3, part of which is seen in the foreground and to the lower right. Alcove #2 (with figure) is in the middleground, and alcove #1 is hidden behind and to the left of the sandstone ridge immediately behind the prospector. C, View looking northeast from the deepest point of alcove #2. Both of the Field Museum skeletons came from the area just toward the viewer, to the left of where I am prospecting. Note the landmark feature on the horizon, an erosional remnant pillar about 45 ft above the microfaunal level. Of the two other specimens of Protoptychus known, or believed, to have come from the Wash- akie, the best is a Carnegie Museum specimen (CM 9386, fig. 5) which came from near the North- west flank of Haystack Mountain (i.e., western end of the Mammoth Buttes of Cope, 1884) from an area located about a mile east of Manuel Gap, along the Manuel Road across Adobetown. This would place it somewhere near the section line between sections 26 and 27 of T16N, R97W, (Manuel Gap Quadrangle, Sweetwater County, Wyoming) about halfway between my localities FM-2-56-WDT and FM-3-56-WDT, nearest FM- 1 -56-WDT. This is shown on the same NW Quad- rant map as the main Protoptychus locality (Turn- bull, 1978, pi. 2), and lies four miles NNE of it. Accordingly, this locality must be close to the Bed 640 level too, although it could be from a unit as low in the section as Bed 630, or as high as Bed 644. The specimen was found by Anne Zangerl in 1941, and she, Rainer Zangerl, and John Clark collected it, giving it Carnegie Museum field num- FIELDIANA: GEOLOGY ^ >,.-. »«i- B Fio. 2. Continued. ber 2-15/1941. As found, the specimen was artic- ulated, lying in a lightly indurated fine sandstone matrix very much like the Protoptychus SS, the unit that yielded the Field Museum specimens. It consisted of a partial skull and most of the skel- eton. Subsequent preparation has freed many of the bones, including the skull, unfortunately at the expense of certain limb and body proportion data. Figure 5 shows the specimen in its present state, consisting of the partial skull (lacking the braincase and lower jaws), the articulated distal portion of the right hind limb (tibia, fibula, astragalus, cal- caneum, and another tarsal), part of the left hind limb (proximal half femur and metatarsals II, III, and IV), four presacral vertebrae (three lumbar and one posterior thoracic or anteriormost lum- bar), most of the sacrum, and an articulated string of six of the proximal caudal vertebrae, two distal TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 '■ *;_*•' ->%., '•' FIELDIANA: GEOLOGY caudals. the right ulna, and some loose and/or broken foot bones and scraps. The other specimen purported to be from the Washakie is the type of Protoptychus? smithi Wil- son, 1937, Yale Peabody Museum specimen num- ber 13189. It consists of a fragment of a left max- illary with P*-M2 and is here referred to as P. hatcheri. Locality data for this specimen are poor and quite vague (35 mi. south of Black Buttes). Wilson (1937, pp. 447, 45 1-452) has reviewed the situation and discussed the problem at some length, and arrived at the conclusion that not seen, "a much damaged facial region, PU 1 1 230." (Albert Wood in his criticism of this manuscript says, "When I last saw 1 1230, it was an edentulous skull.") In the type, the dentition had reached a fairly advanced stage of wear and much detail of the original crown features of its teeth had been worn away in life. It was found in the Uinta Basin, Wagonhound Member of the Uinta Formation, and thus it and the Washakie specimens are of approximately the same age (fig. 1). It is illustrated in Figure 6B. ... it is most probable that Protoptychus? smithi is from beds of upper Bridger or lower Uinta age in the Washakie Basin. Geographic evidence points to the former age. Stage of evolution of the fragmentary rodent fauna indicates an upper Eocene assemblage. The author favors an Uinta age for the Yale species. We now know that there are Uintan aged beds on the Northwest flank of Haystack Mt. and the Adobetown Rim areas adjacent it, and that these outcrop areas lie even closer to Black Butte, albeit to the east-southeast not south, than does Hay- stack Mt. proper, which is even farther east and was the only upper Eocene stratum in the area known to Wilson in 1937. Hence, the geographic problem is lessened, and Wilson's conclusion is reinforced by the presence of Uintan outcrops closer to Black Butte. Furthermore, for the early workers the area of the northwest flank of Hay- stack would have been most easily worked from either Red Dog Buttes (now known to be most likely the old Tadpole stage station north of Hay- stack Mt. proper, fide P. Robinson, pers. comm.) or from the LaClede station. Both abandoned stagecoach stations on the old overland trail served as base camps for some of the early Yale collecting parties, and both were accessible from the Union Pacific railroad via Bitter Creek station. I show / ' smithi here for comparison in Figure 6A. Unfortunately, until now the type species of the genus Protoptychus, P. hatcheri, has been known only from its holotype, PU 11235, the well-pre- served skull of an aged animal, and according to Wahlert (1973) from another specimen that I have Descriptions (See Table 1 for measurements.) Skull and Bulla Wahlert (1973) has made the most recent schol- arly study of the type specimen. He updated and refined the description of the skull beyond that given by Scott (1895), and he revised the various earlier interpretations regarding its systematic po- sition such as those of Winge ( 1 94 1 ) and KJingener ( 1 964). For the cranium Wahlert noted a series of features, many of which had been noted by Scott, but he then commented on those deemed to be of significance in determining relationships of the ge- nus (Wahlert, 1973, pp. 6-8), and devoted the re- mainder of the study to an interpretative discus- sion of the possible and probable relationships. I have little to add to Wahlert's description and discussion, and rather than repeat it, I simply fol- low his format in the same order for the Field Museum specimens, adding comments where ap- propriate: 1) Posterior Extensions of the Nasals— Be- cause of the uniqueness of this feature among ro- dents, it is useful for characterizing the genus, but gives little insight into relationships. 2) Auditory Region— Here I have several comments and some descriptive additions. The bullae are indeed greatly inflated. They are so ex- panded dorsally and ventral ly that they come close Fio. 3. The first Field Museum Protoptychus skeleton, PM 8018. Note that the left bulla is damaged and the left manus, pelvis, and tail, as well as portions of both hind limbs, are missing. The huge right bulla can be seen to protrude and surround the parietal-occipital region and to reach up to the midline of the skull. The disproportionate size relationships between fore and hind limbs is evident even without the complete femur. Approximately x 1. Fig. 4. The second Field Museum Protoptychus skeleton, PM 39371. Approximately x l. TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 FIELDIANA: GEOLOGY to meeting at the midline both above and below the cranium. But the inflation, which involves temporal, mastoid, and occipital portions of the skull, is actually the result of inflation of tympanic, mastoid, and (?) exoccipital bones with the mas- toid expanded into the temporal region. Damage from exposure prior to its discovery has resulted in the left bulla of PM 80 1 8 being opened dor- solateral^ and dorsoposteriorly to reveal some- thing of the internal structure. Within the damaged bulla, one can discern that the major portion of the (dorsal) mastoid chamber was broadly open in its ventral portion, for the damage has opened it nearly to its base, a dividing septum that remains intact anteromedially. The opening extends well into the posterior, (?) occipital/mastoid chamber to reveal a small bit of its floor posteriorly. This floor is also a presumed septal partition separating the occipital chamber from the main ventral tym- panic chamber. The damaged area extends down to the meatal opening which either is totally oblit- erated, or if not is a broad hollow trough that immediately rolls ventrally into the main tym- panic chamber near its lateral wall. Medial to this, near the medial wall of the bulla, there is a con- vexly rounded structure that I take to be part of the petrosal (promontorium), but no clearly iden- tifiable features are exposed. 3) Parietal-Bullar Relationships— Here I find some degree of variation. Wahlert had noted that in the type the parietal overlapped the dorsal (mastoid) epitympanic sinus portion of the bulla, and I find this to be the case in PM 39371 also. However, in the right bulla of PM 8018, in which the bulla is more expanded dorsally (and perhaps also slightly distorted in that direction), it is the bulla that overlaps the parietal and even the in- terparietal. 4) Cranial Foramina— The incisive foramina are indeed elongate. I interpret this as a special- ization of unknown significance. It is quite com- parable to the condition in Jaculus j. flavillus in which the posterior margins have migrated back to the same level with respect to M' (P4 missing or vestigial in Jaculus), and the premaxillary- maxillary suture intersects the lateral margin of the foramen in a similar anterior position. 5) Infraorbital Foramen— The infraorbital foramen is, as Wahlert (1973) stated, "considerably larger dorsoventrally than that of any protrogo- morphous rodent." I measure it to be 0.66 cm in the type (0.49 to the dorsal step within the long axis of the oval opening) by -0.23 cm maximum in the shorter, lateral axis of the oval. For the Field Museum and Carnegie Museum specimens the comparable measures are: PM 8018, left = 0.65 cm x ~0.20 cm; PM 39371, left and right = 0.60 cm x ~0.21 cm; CM 9386, long axes of both left and right are estimated to be about 6 mm, but no short axis measure is possible. Wahlert thus concluded (1973, p. 7), "Protop- tychus was hystricomorphous." In the sense that the foramen is greatly enlarged over all protro- gomorphous forms, it does suggest the hystrico- Fio. 5. The Carnegie Museum specimen of Protoptychus, CM 9386, as it is today. A, Ventral, left lateral, dorsal, and front views of the skull. B, Approximately lateral and medial views of right ulna. C, Anterior and posterior views of proximal half, left femur. D, Posterolateral and anteromedial views of left tibia, fibula, astragalus, calcaneum, and one other tarsal in articulation as found. E, Nearly dorsal and ventral views of the left metatarsus. F, Articulated string of four complete and two partial proximal caudal vertebrae, about numbers 1 1 through 17 to judge by the reduction of processes and relative lengths. G, Dorsal (mostly hidden) and ventral views of the sacrum. Fio. 6. A, The Yale University specimen, the type of Protoptychus smithi Wilson, YPM 1 3 1 89, a left maxillary shown in ventral view. Note the faint trace of the filled alveolus of the P\ It can also be seen (in side view) in the x-ray (above). B, The Princeton University specimen, the type of Protoptychus hatcheri Scott, PU 1 1235, shown in ventral, left lateral, dorsal, right lateral, and posterior views. Outline drawings are labeled according to the following scheme: BO ■ basioccipital bone, Cond = condyle, EAM - external auditory meatus, EoB - exoccipital portion of bulla, FM - foramen magnum, Fr - frontal bone. Incisor - upper incisor on broken section and in "window" near the infraorbital foramen, IoF = infraorbital foramen, Ip - interparietal bone, M1 and M2 ■ upper molars 1 and 2, Max = maxillary bone, MB ■ mastoid portion of bulla, N - nasal bone, PJ and P4 = upper premolars 3 and 4, Pa = parietal bone, Pmx = premaxillary bone, Pt = pterygoid bone, So •= supraoccipital bone, St + JuF = location of stapedial and jugular foramina, TyB - true tympanic portion of bulla, v-Pop ■ vestigial paroccipital process. C, Protoptychus hatcheri, PM 80 1 8. Skull and jaws shown in left lateral and left anteroventral views, and skull in posterior view. D, Protoptychus hatcheri, PM 39371. Skull and jaws in left lateral view and in ventral view with the left jaw ramus removed to expose the left upper dentition. TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 Incsor Cond 10 FIELDIANA: GEOLOGY TURNBULL: PROTOPTYCHUS HATCH ERI SCOTT, 1895 11 Table 1 . Measurements (in mm) of some features of the skull and jaws of various specimens of Protoptychus. hatcheri Type PU 11235 smithi Type YPM 13189 hatcheri CM 9386 PM 8018 PM 39371 PM 2084 PM 2303 PM 2304 Skull Length Greatest breadth (zygoma) Greatest breadth (bullae) >32 >19 <20.5 - »14.2 33.8 * -21 -33 -20 -23.5 - - - Palate Length (midline suture) Width at P-M' Width at M2-M3 6.2 4.6 5.2 - 7.4 4.6 4.8 * • * « * * - - - Bulla Height Anterior-posterior diameter 13.9 13.5 — — * 15.4 13.3 14.1 — — — Cheektooth row Length P-M3 Length P-M2 Length P-M1 Length M'-M2 Length M'-M3 Length M2-M3 7.1 5.3 3.5 3.6 5.4 5.6 3.4+ 3.9 7.7 5.6 3.6 4.0 6.0 * * * * * * * • * * * -3.6 3.8 7.6+ 5.8- 3.8- 3.9+ 5.8 + 3.7 PM 8018 PM 39371 PM 2301 PM 2305 PM 2312 PM 2319 PM 2323 PM 2324 Jaws Ramus length (incisor alveolus to rear of condyle) Ramus depth beneath M, Height of ascending ramus (perpendicular to and above cheektooth row) -18 -6.3 -2.5 -19 -6 -3 — — — 5.2+ — 5.3+ Cheektooth row Length P4-M3 Length P4-M2 Length P4-M, Length M,-M3 Length M,-M2 Length M2-M3 * * * * * * * * * * * * 4.4 4.7- 4.1- 8.7 6.7 -4.3 6.5 4.3- 4.3 + 3.8+ 8.2+ 6.5 + 4.4+ 6.5 4.1 4.5 * Feature present but inadequately exposed for measuring morphous condition. But to me it also suggests the myomorphous condition, and in fact it fits that state closer than it does the hystricomorphous state in terms of the size and proportions of the opening. Whether hystricomorphous or myomorphous, it is the anterior portion of the zygomaticoman- dibularis that invades the surface of the snout via the foramen, thereby becoming the maxilloman- dibularis (deep masseter or masseter medialis of many authors). I have shown the condition for both a myomorph and a hystricomorph (Turnbull, 1970); I now suggest that, in as much as the my- omorphous state is intermediate between the (primitive) protrogomorphous and the (most spe- cialized) hystricomorphous states with regard to degree of invasion of the infraorbital foramen by muscle, we might do well to modify Wood's ( 1974) concepts slightly. I suggest that rather than con- sider the myomorphic condition to be "a combi- nation of the hystricomorphous and sciuromor- phous types" (Wood, 1974, p. 23) we consider it to be a structural intermediate between protro- gomorphous and hystricomorphous types, with little bearing on the sciuromorphous type, which constitutes a different sort of specialization that does not involve the infraorbital foramen. Here Klingener's 1 964 study of dipodoid myology is particularly informative, and although my inter- 12 FIELDIANA: GEOLOGY Table 1. Continued. katcktn f Range PM PM 2322 PM 8004 PM 8029 PM 37373 PM 37382 PM 37384 PM 37385 2306 Min. Max. N(N) >32 33.80 3 — — — — — — — — >19 -20 2(3) — — — — — — — — <20.5 -23.5 3 _ _ _ _ _ _ 6.2 7.4 2(4) — — — — — — — — 4.6 4.6 2(4) — — — — — — — — 4.8 5.2 2(4) ^ _ _ _ 13.3 13.9 2(3) — — — — — — — — 13.5 15.4 3 __ 6.8 + 7.3+ 7.3 ^ 7.9- 6.8 + 7.9- 7(9) -6.1 5.9 -5.4 -5.4 — 5.7- 5.6 5.9 + -5.4 -6.1 11(13) -4.1 -3.6 3.4+ 3.8 + — 3.8 3.6- 3.9- 3.4+ -4.1 12(14) 4.0 4.1 3.8 -3.9 — 4.0 3.9 + 4.2 3.6 4.2 11(13) — — -5.4 5.6 + — 5.9 — 6.2- 5.4 6.2- 7(9) — — 3.4+ -3.5 3.6 3.9- — — 3.4 + 3.9- 9(11) PM PM PM PM PM PM PM PM 8005 8006 8009 8010 8011 39830 39831 39832 1.8 1.9 2 — — — — — — — — 5.2+ -6.3 4 -2.5 -3.0 3.9 7.8 + 7.5 + — 5.7 + 5.1 + 6.1 3.7+ 3.5- 3.7 + 6.3 + 5.7 + — 3.9+ 3.6 4.2+ 4.3 + 4.1 — 4.1 6.4 4.3 3.7 - 4.4- - — 7.5 + 8.7 4(6) 5.9 5.1 + 6.7 7(9) 3.5 + 3.5- 4.7 + 13(15) — 5.7 + 6.5 4(6) 4.2 3.6 4.3- 7(9) — 3.9 4.5 5(7) (N), potential sample size if buried structures are ever exposed. pretation differs somewhat from his, I believe his work supports my position (see discussion on p. 14). I find that I differ from Wahlert in a minor way in my observations concerning the snout. The sides of the snout are indeed flattened, but the course of the root of the incisor does not make much of a swelling in the type. In it and in both fmnh skeletons the only such swelling is located forward near the alveolar margin. The Carnegie specimen, however, does show the sort of swelling that Wah- lert describes for the type, so that his description does fit one specimen of the species precisely. More posteriorly, the root lies deeper within the bone and enters the pit within the area just in front of the foramen, and for a short distance it appears within a "window" that opens to the surface (fig. 6D). In fact most of the medial wall of the foramen and the area in front of it, where the origin of the maxillomandibularis muscle is presumed to have been located, is multiply fenestrated. Best seen in PM 39371, this unusual muscle origin surface causes me to suspect that the muscle must have drawn offmainly from the unfenestrate peripheral parts of the area, or perhaps from a superficial aponeurosis that also was anchored peripherally. 6) Foramina of Orbital Region and 7) Sphenoidal Fissure, etc.— For these two cat- TURNBULL: PROTOPTYCHUS HATCHER1 SCOTT, 1895 13 egories of Wahlert's, I have no additions or further comments. For these foramina in particular and for many of the others as well, Wahlert (1974) is a most helpful reference. 8) POSTGLENOID, TEMPORAL, ETC. FORAMINA— I believe that the apparent absence of the post- glenoid foramen may be as much the result of reduction of the glenoid as it is due to bullar in- flation. As for the apparent absence of the tem- poral foramen, bullar inflation doubtless is the cause; it may not actually be absent, but just masked by the inflation and the pathway from it hidden. The exit could be almost anywhere along the slit between the dorsal bullar chamber and the parietal bone. With regard to a carotid canal, I cannot pinpoint it on either of the better preserved fmnh specimens, but the jugular foramen and the fissure medial the bulla could well provide access, so I see no compelling reason to assume its absence. The stapedial foramen (seen only in the type) opens laterally within the common pit for it and the jug- ular foramen, just lateral to the occipital condyles. It is located in the identical position as is that foramen in modern Jaculus. At this point it is worth while to look beyond Protoptychus at conditions in its living analogues. Klingener (1964) reported the masseter muscle of dipodoids to be hystricomorphous. He gave two criteria: 1) "M. masseter lateralis profundus does not extend anterodorsad on a zygomatic plate, as it does in myomorphous and sciuromorphous types," and 2) "Part of M. masseter medialis an- terior originates from the rostrum anterior to the infraorbital foramen and passes posteroventrad through the foramen to insert on the mandible, in contrast to the sciuromorphous and protrogo- morphous types." These two criteria are important and figure fre- quently in the remainder of this discussion, and in Figure 12. For ease in discussing them, I simply use "Zygomatic Plate" to carry the full meaning of Klingener' s first criterion, and "I.O.F." for his second. Most rodent specialists now agree that the protrogomorphous type is primitive and general- ized, and that the other three types represent spe- cialized advances, all providing enhanced incisor function through greater leverage advantage of the masseter. From here on, there is less uniformity of opinion. I believe that each of the three spe- cializations is distinctive. That of the sciuromor- phous type, involving as it does the superficial mas- seter and a Zygomatic Plate, goes off in one direction while that of the hystricomorphous type, involving the deep masseter and the I.O.F., goes in a distinctly different direction. Those rodents that 'discovered and used' both ways of enhancing masseter function, we have come to know as my- omorphous types. This specialization, while mak- ing use of both of the others, is in a sense inter- mediate, but I contend is just as distinctive. The degree of use of the I.O.F. is always limited— never reaching the maximum extent seen in advanced hystricomorphous types, and the extent of Zygo- matic Plate development varies between little and the full-blown degree of most myomorphous forms. Klingener (1964) concluded that the myomor- phous masseter of muroids could have evolved from any of the other three types. He believed that while all are possible ancestral types, only the hys- tricomorphous type is the most likely. To me, der- ivation from the protrogomorphous type appears to be most likely. For it to be derived from either of the other two specialized types would involve some degree of reversal of one or both sorts of specialization of the masseter. Hence, I see the myomorphous type as a distinct specialization in its own right, one in which both superficial and deep masseter adjustments were involved togeth- er. Thus from the protrogomorphous type all three specialized types evolved independently: sciuro- morphous by Zygomatic Plate development, hys- tricomorphous by I.O.F. invasion, and myomor- phous by both. This seems most parsimonious in that each specialized route is independent, and no reversing of a specialized trend is required. Mandibles (Figure 7) (See Table 1 for jaw measurements.) The jaws of Protoptychus are delicately built, more massive in the areas surrounding the dental region than elsewhere, and the horizontal ramus is relatively deep. The ascending ramus is thin, narrow, and elongated. The condyle is small and oval in its occlusal outline with its long axis aligned with the anteroposteriorly elongated glenoid. The coronoid process is a spikelike extension of the anterior edge of the ascending ramus. This re- markably elongate coronoid appears to be a mod- ification in response to raised posterior area of muscle origin resulting from the extreme bullar inflation. The angular process draws off from the lateral side of the jaw, lateral to the incisor, behind the last molar. This is best seen in PM 2319, which is broken across the region near the forming "root" end of the hypsodont incisor. Thus Protoptychus 14 FIELDIANA: GEOLOGY Fio. 7. Protoptychus hatcheri, PM 39371, left lower jaw. A, lingual view. B, dorsal view. C, posterior view. D, lateral view. In C, the arrow points to the condyle of the jaw. is weakly or incipiently hystricognathous, but I do not find this feature to be a very satisfactory char- acter because all sciurognathous-hystricognathous distinctions are blurred for the primitive hystri- cognathous condition. I therefore consider this feature to be at most a weak indication of the direction of evolution rather than accepting it as indicative of the full-blown shift from the sciurog- nathous state. The symphysis is short, relatively small, and far forward beneath the anterior half of the diastema. The mental foramen is located beneath the posterior half of the diastema. It is usually oval, but may have a slight constriction in its middle (PM 39371). The masseteric fossa is shallow but extensive and distinct. There is a no- ticeable boss just dorsal to its anterior, pointed end, lateral to the P«. I now believe that I misled Wahlert in 1973 with my statement about a pars reflexa of the masseter muscle. The ventral edge of the ramus does look as though there might have been one, but it could not have been very large and I can see no demarcation of an insertion field where it would be expected along the groove be- neath the root of the incisor or low on the medial side of the jaw. Dentition (See Table 1 for toothrow dimensions and Tables 2-4 for individual tooth measurements.) The dental formula is I1,, C°0, P2i, M3,. This is contrary to that originally stated for the species (and for P. smithi). Both Wilson (1937) and Wah- lert (1973) reported the presence of the minute P3 of P. hatcheri, and Wahlert shows it in his figure 1 . Scott had missed the little peglike P3, which is so reduced a tooth that it probably had no function beyond serving as a buttress for the P4. In the type TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 15 Table 2. Protoptychus upper cheektooth measurements (in mm). P3 P4 L W I. AW PW P. hatcheri type PU 11235 0.5- 0.5+ 1.6 1.7 1.8 + P. smithi type (alv.) (alv.) YPM 13189 -0.4 -0.4 1.6 -1.7 -1.8 P. hatcheri (alv) (alv) CM 9386 0.5 + 0.5 + 1.6+ 1.7- 2.0+ PM 8018 -0.5 -0.5 1.9+ * * PM 39371 0.6+ 0.5- 1.8 1.8 1.8 PM 2084 — — 1.4+ 1.7 1.9- PM 2302 0.8 (alv.) 0.7 — — — PM 2303 — — — — — PM 2304 0.6+ (alv.) 0.6 1.6- 2.0- 2.1 PM 2306 0.5+ (alv.) 0.5 + 1.9+ (alv.) 2.0- 1.8 PM 2307 PM 2321 -0.6 (alv.) 0.5 1.6- 1.8 + 2.0- PM 2322 0.5+ (alv.) 0.5 + 1.7- -2.0 -1.8 PM PM 8004 0.5+ (root) 0.3+ 1.2+ 1.9- -1.9 PM 8007 -0.7 (alv.) 0.7+ -1.5 -2.1 (alv.) -2.0 PM 8008 (all alv.) 0.7+ 0.5 + 1.4+ -2.0 -2.0 PM 8029 0.7+ (alv.) 0.7+ -1.8 -2.2 2.3 PM 37373 — — — — — PM 37381 -0.8 (alv.) -0.7 -1.8 -2.1 -2.4 PM 37382 0.4+ 0.4+ 1.6+ 2.1- 2.0 PM 37384 0.8- 0.7 1.5 + 2.0+ 2.0 PM 37385 -0.9 (alv.) -0.9 1.6 2.2- 2.3 PM 39824 0.5 (root) 0.4 - 2.0 (root) Obs. range Min. 0.4 0.3 1.2 1.7 1.8 Max. 0.9 0.9 1.9 2.2 2.4 N 18 18 17 17 16 Mean 0.54 0.56 1.61 1.95 2.01 L, length; W, width; AW, anterior width; PW, posterior width; b, broken. specimen it is present on the left side, missing on the right, but its root and alveolus are apparent (fig. 6B). It is indeed surprising that such a careful worker as Scott missed seeing it. In P. smithi no tooth is present in the P3 position, but there is, I believe, a trace of one, which Wilson might have seen had he had the evidence of an x-ray photo of the specimen. Only an indistinct vestige of a small alveolus gives evidence of its presence, to judge by the appearance of the bone surface just anterior to the P4. It was a small, single-rooted tooth that appears to have been shed in life (fig. 6A). Its alveolus was remodeled, partly filled, and nearly obliterated, as the x-ray confirms (fig. 6A). In my larger sample, in every case in which the appro- priate area is preserved, the tooth (or its root or alveolus) is present, but it does vary considerably in size from a diameter of about 0.4 mm to 0.9 mm (table 2). In as much as these measures were taken on whatever structure was available (tooth, root, or alveolus), the variation is doubtless ex- aggerated. The larger sample thus demonstrates the consistent presence of a P3 in the species, as well as its variable size and crown structure. I find Wahlert's description of the upper den- tition to be satisfactory in every detail. The suite of specimens now at hand shows the spectrum of wear stages for most teeth (fig. 8A-G); most no- table in this regard is the unerupted P4 of specimen PM 39371 (fig. 8G), which is in its pristine con- dition. The best preserved P3 has a crown divided into anterior and posterior moieties, the posterior being taller, and it has a worn tip. The upper den- tition is shown in a conventional diagram (fig. 8H) 16 FIELDIANA: GEOLOGY Table 2. Continued. M' M* M* L AW PW L AW PW L AW PW 1.8- 2.1 2.0 1.8- 1.9+ 1.8- 1.8 1.8 + 1.5 + 2.0- 2.3 2.0 1.8- 2.0+ 1.8 + - - - 2.0 2.1 2.2 2.0- 2.2+ 2.1 + 1.7+ 2.0- 1.7- • • • * • • * * • 1.9+ 2.1 + 2.2- 1.9- 2.0+ 2.0+ 1.7- 1.9+ 1.7 + -1.8 2.0 b — — — - - - 1.7 + 1.9 + 1.9 1.8 1.9 + 1.9 _ _ 2.1- 2.3 + 2.3 2.0- 2.1 2.0 1.7+ 1.9 1.5 + -2.0 2.3 2.2 -1.9 2.1- 1.9+ "™ "■" ~ -1.8 -2.5 2.5 2.1 2.2 + 2.1 + - — - 1.9- 2.0+ -2.1 1.9 2.2+ 2.2- _ ^ -1.6 -2.2 (alv.) -2.2 + — -2.3 (alv.) — — — — -1.9 -2.7 -2.3 -1.8 -2.2 -2.1 — -1.6 — 1.8+ -2.4 2.2 1.8 + 2.2- 2.0+ -1.5 2.0+ -1.7 (root) 2.0+ 2.0+ 1.8 2.2+ 2.1- 1.6 + 1.8 1.7+ — -2.7 — — — — — — — 2.0- 2.2- 2.2- 2.0- 2.1 + 2.0 1.8 + 1.8 1.7- 1.9+ 2.2- 2.3 2.0- 2.2- 2.2- — _ — 2.1- 2.5 2.6 2.0 2.4- 2.2 1.9+ 2.2- 2.0+ 1.6 1.9 1.9 1.8 1.9 1.8 1.5 1.6 1.5 2.1 2.7 2.6 2.1 2.4 2.2 1.9 2.2 2.0 16 16 16 14 15 14 7 8 7 1.89 2.24 2.20 1.91 2.15 2.03 1.71 1.89 1.69 • Feature present but insufficiently exposed for measurement. of crown features, labeled to follow closely the scheme used by Wood ( 1 962, p. 8). Bivariate plots i length by width or anterior width) for each of the upper teeth show all of the measurable specimens (collected prior to the 1986 field season) including the types of P. hatcheri and P. smithi (fig. 10). For the lower dentition a similar suite of wear stages is now available (figs. 8 J, 9), and a diagram comparable to that for the upper dentition is pre- sented (fig. 81). The lower incisor is enamel-cov- ered on its slightly wider, gently curved ventral surface. This form, and the oval cross section, cause the chisel-shaped worn anterior end to be beveled. The P4 is elongate with a complete but small tri- gonid. Its talonid is larger than the trigonid and the talonid basin has a small cuspule in its center. The hypolophid is bent with a posterior kink in its ridge between hypoconid and entoconid. The ridged hypoconulid connects with both hypoconid and entoconid, and there is a valley between it and the entoconid. The lower molars are lophate, but the lophs are interrupted in the early wear stages. The protolophid, connecting protoconid and metaconid, lies far forward at the anterior edge of the crown. The hypolophid is distinct and straight in both M, and M2, but M, lacks this feature in its reduced posterior region. The short, broad, and deep talonid basin enters from the labial side and divides each tooth into anterior and posterior moi- eties. As was done with the upper teeth, bivariate plots of the lower teeth have been made (fig. 10), and they all appear to be reasonably tight, as might be expected for samples from a single taxon. Because TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 17 Table 3. Protoptychus hatcheri lower cheektooth measurements (in mm). dP< P< L AW PW L AW PW PM 8018 * * * PM 39371 1.7+ 1.1 1.4 — — — PM2100 — — — — — — PM 2301 1.8 + 1.1 1.2 — — — PM 2312 — — — 1.7+ 1.1 + 1.6- PM 2319 — — alv. 2.1- 1.4- 1.8 PM 2323 — — — -1.6 1.4- 1.5 PM 2324 — — — -1.8 -1.3 -1.6 PM 2326 — — — 1.8 1.3 -1.5 PM8005 — — — — — — PM8006 — — — wl.3 — b>1.0 PM8009 — — — 1.5 1.3 1.4- PM 8010 -1.8 w>1.0 wl.3- — — — PM8011 — — — 1.7 1.5 1.6 PM 37375 — — — — — — PM 37376 — — — — — — PM 39829 — — — — — — PM 39830 — — — 1.9- 1.5 + 1.6+ PM 39831 — — — wl.9+ wl.0+ wl.3+ PM 39832 - - - b~1.8 b~1.2 1.4+ Obs. range Min. 1.7 1.0 1.2 1.3 1.0 1.0 Max. 1.8 1.1 1.4 1.9 1.5 1.8 N 3 3 3 10 10 9 Mean 1.77 1.07 1.30 1.70 1.30 1.50 ±SE - - - 0.19 0.16 0.11 L, length; AW, anterior width; PW, posterior width; b, broken; r, root; w, worn. all sample sizes are small, no statistical assess- ments were attempted. Postcranial Skeleton Table 5 presents a series of measurements of Protoptychus and some modern ricochetal ro- dents, Table 6 gives a schematic view of the ver- tebral column as preserved in the three partial skeletons, and Figure 1 1 compares limb and body proportions of Protoptychus and some compara- tive specimens. For comparative purposes three published studies provide a sound basis: Lyon (1901), Hatt (1932), and Howell (1932). Vertebral Column and Ribs— Description of the details of the vertebral column, in spite of the existence of three partial skeletons, must remain incomplete. For the two articulated skeletons, much remains buried in matrix, and I dare not risk fur- ther preparation of either for fear of causing un- acceptable damage. I have been unable to get suf- ficient x-ray penetration of the imbedding matrix to provide a clear picture adequate to give verte- bral counts, let alone details of form. Nor has a computerized CAT scan resolved these details. For the other "skeleton," the Carnegie specimen, many of the vertebrae which had been present originally, or represented by impressions, are now missing, probably destroyed by the preparation efforts made shortly after its discovery. The sandstone matrix is not the most ideal medium for preservation of such delicate remains. Once removed from their matrix they readily disintegrate, even when given great care. Unfortunately, use of penetrating hard- eners, which is essential in dealing with such del- icate materials, was not attempted in this case. In Table 6 the status of each vertebra and rib for each of the three specimens is shown. The cervicals are largely buried in matrix in both PM 8018 and PM 3937 1 . In the former, enough shows to reveal that the dorsal side of the neural arch of the atlas con- sists of a slender, arching, spineless strut of bone. Of the axis, only a bit of its apparently well-de- veloped dorsal spine can be seen. I cannot tell whether any cervical fusions exist. The bone is not 18 FIELDIANA: GEOLOGY Table 3. Continued. M, M, M, L AW PW L AW PW L AW PW • • • * • • • • • 1.9 1.8+ 1.9- 1.9 + 2.0- 2.0- 2.0+ 1.8- 1.7- 1.9 2.0 1.9- — — — — — — 2.0 1.8- 1.8- — — — — — _ 2.0 2.0+ 2.1 + — — — — — _ 2.1 1.7 + 1.9 2.1 1.9 1.9 2.2 1.8 1.7- 2.0 1.6 1.7- _ _ _ _ 2.1 1.9- 1.8 2.1 2.0+ 2.1 2.1 + 1.8 1.6+ r-2.0 rl.6- rl.6+ 1.9+ 1.8 + 1.8 + 1.9- 1.7- 1.3+ 1.9+ 1.6 1.7 1.9 1.7- 1.7- r2.0- b>1.4 1.5 + 1.8- 1.7 1.7 1.8- 1.6 1.7 1.8+ 1.4+ 1.4- 2.0 1.6 1.7 1.9+ 1.7- 1.7 + — — — 2.0+ 1.8- 1.9 — — — — — — 1.8+ 1.6 + 1.7 1.9+ 1.6+ 1.7 + — — — — — — 2.2- 1.9 2.0+ — — — — — 1.7- 1.9+ 1.8- 2.0- — 1.7- — 2.1 1.9- 1.9- 2.2- 2.0+ 2.2- — — — wl.9- wl.4+ wl.7 + — — — — — — 2.0 1.9 2.0 2.2+ 1.8+ 2.0- — — — 1.8 1.4 1.6 1.8 1.6 1.7 1.8 1.4 1.3 2.1 2.0 2.1 2.2 2.0 2.2 2.2 1.8 1.7 15 15 15 12 12 12 5 7 6 1.97 1.75 1.83 1.91 1.82 1.90 2.00 1.70 1.53 0.10 0.17 0.13 0.32 0.15 0.18 — - - * Structure present but insufficiently exposed for measurement. mineralized enough to show on the scan, which suggests to me that fusions are unlikely. The anterior thoracics are similarly buried in both specimens. There appear to be at least ten rib-bearing vertebrae, but as yet I cannot present any details of their structure or even be absolutely certain of their number. In PM 80 1 8, portions of the last four rib-bearers, T-7 through T-10, are exposed dorsally behind which there are three more reduced neural spines that I take to be those of T-ll through T- 13. The lumbars apparently number seven. In PM 8018, just above the flexed knee one can see the trace of the impression of the centrum of the miss- ing fifth lumbar. Anterior to this there is another impression with traces of bone that represent the fourth lumbar, and in series in front of it are most of lumbars #3, #2, and #1. In PM 39371 the pos- terior five lumbars are exposed, but the anterior two are buried. In the Carnegie specimen there are three certain lumbar vertebrae that I take to be #4, #6, and #7, and there is another vertebra that is probably lumbar #2 or #1. All of the lumbar vertebrae have expanded anterior transverse pro- cesses, least so in the anterior three, and progres- sively more prominent and forward-sweeping in the more posterior ones, best seen in CM 9386. The three (or possibly four) sacrals are best seen in CM 9386 (fig. 5G). They are subequal in length, but the first has the widest and longest transverse processes for articulation with the pelvis. The sec- ond and third have progressively narrower trans- verse processes. All are fused into a perforate, ar- row-shaped overall form with paired neurovascular perforations just lateral to the points of junction of adjacent centra. It is likely that with advanced age the fusion was increased, and the degree of articulation with the pelvis expanded posteriorly comparable to the condition seen in other mam- mals, including modern kangaroo rats and jerboas, but there is no direct evidence in support of this. Dorsally, there is a low neural arch and spine on each vertebra. The centra measure 0.44, 0.42, and 0.54 cm in length. The caudals, absent on PM 8018, and nearly so on PM 39371, are best known from CM 9386, TURNBULL: PROTOPTYCHUS HATCH ERI SCOTT, 1895 19 Table 4. Cross-section measurements of incisors of Protoptychus hatcheri. Upper incisors Lower incisors Specimen Length (long axis) Width (short axis) Length (long axis) Width (short axis) PU 11235 Type 2.0- 1.1- CM 9386 2.2- 1.5- — — PM 8018 2.2+ 1.2+ 2.0 1.3 PM 39371 2.2- 1.1 + 1.8 1.2- PM 2308 2.3 1.4- — — PM 2309 2.4- 1.4- — — PM 2310 2.4- 1.4- — — PM 2319 — — 2.0- 1.2+ PM8003 2.3- 1.1 + — — PM8009 — — (1.5) (1.0) PM 8010 — — 2.0+ 1.2 PM8011 — — 1.9 1.2+ PM8015A — — 2.0 1.2 PM8015B 2.4 1.4 — — PM 37377 1.9 1.1 — — PM 39827 2.5 + 1.5 — — PM 39828? 2.0- 0.9+ — — PM 39832 — — 1.9- 1.2+ PM 39836 2.3+ 1.4+ — — PM 39839 2.6 1.4+ — — N 14 14 7 7 Obs. range 1.9-2.6 0.9-1.5 1.8-2.0 1.2-1.3 Jc± SE 2.26 ± .20 1.28 ± .19 1.94 ± .08 1.21 ± .04 Including dubious specimen N — — 8 8 Obs. range — — 1.5-2.0 1.0-1.3 x± SE — - 1.89 ± .17 1.19 ± .08 which preserves parts of the midproximal five ver- tebrae, complete and in articulation with one an- other and with the proximal fragment of a sixth (fig. 5F). The first of these is short, and may be a sacral. It measures 0.8 1 cm, almost twice the length of each of the three usual centra of the sacrum, and possesses narrow but well-developed transverse processes. The second is elongate, measures 0.98 cm, and has traces of transverse processes ante- riorly. The third, fourth, and fifth are each slightly longer than the second, measuring 1.10, 1.10, and 1.08 cm. Clearly these elongated midproximal caudals indicate that the tail was an elongated, powerful balancing organ. They are proportion- ately as large as, if not larger than, those of living kangaroo rats or jerboas (see table 5), all of which exceed those of nonricochetal forms. Pectoral Girdle and Front Limb— The scap- ula is delicate, long and narrow throughout, and widest at its rounded vertebral margin (best seen in PM 8018, fig. 3). The spine is high and extends nearly to the margin. Supra- and infraspinatus fos- sae are deep and elongate, the latter bordered by a marginal axillary spine. Humerus, radius, and ulna are correspondingly delicate. The humeral head, neck, and greater and lesser tuberosities are all bunched together. The shaft of the humerus is slender, its distal articulation broad, and the ent- epicondylar foramen is relatively large with troch- lea, capitulum, and coronoid fossa well developed, as is the deltoid crest, which reaches nearly to midshaft. The shaft of the radius is straight with the usual tuberosity and neck beneath the cupped head. Distally the articulation is unremarkable ex- Fig. 8. A-G, A series of maxillary specimens of Protoptychus hatcheri demonstrate some of the variation seen in the population from the main locality. Specimens shown are: A, PM 8004. B, PM 2304. C, PM 2307. D, PM 2303. E, PM 2322. F, PM 8008. G, PM 39371. H, I, Upper and lower cheek tooth diagrams, respectively. J, The lower cheek dentition of PM 39371. A-F are shown approximately x6; G and J, approximately x 7.5. 20 FIELDIANA: GEOLOGY TURNBULL: PROTOPTYCHUS HATCH ERI SCOTT, 1895 21 22 FIELDIANA: GEOLOGY ~i 1 1 r- 1.5 17 19 2.1 hi 6 14 12 h 10 ■1.6 -1.4 -1.2 ■1.0 17 |.9 2.1 2.3 1.4 1.0 18 2 0 2.2 -1.9 -1.7 -1.5 -1.3 I.I 13 1.5 17 19 1.7 1.9 2.1 2.3 Fio. 10. Variation in tooth proportions is illustrated in these bivariate graphs (length by width or anterior width) of each tooth of Protoptychus hatcheri. All measurable specimens are included. O indicates FMNH skeleton; CM, Carnegie Museum specimen; H, P. hatcheri type; S, P. smithi type; X, mean; a, alveolar measure; r, root measure; b, broken; w, worn. cept for its small size. Preservation is poor in the area, so that I have not been able to determine anything about the styloid process. The ulna has a short olecranon and tight semilunar notch about equal to the length of the olecranon; its shaft is gently curved (figs. 3-5). To date no specimen pre- serves the manus, which presumably was corre- spondingly delicately proportioned. Pelvic Girdle and Hind Limb— Here we come to the remarkable enlargement of the girdle and especially the hind limb, which in comparison with most rodents is a noteworthy feature. Each of the three skeletons contributes to our understanding in a different way. PM 3937 1 is the most complete overall, PM 8018 has the most complete tarsus, and CM 9386 affords the best opportunity for ex- amination of the joints and medial aspect of var- ious elements. The ilia flare apart anteriorly and receive the transverse processes of the sacral ver- tebrae. Pubes are rather small with an elongate symphysis (well exposed in PM 39371, fig. 4). Ilia and ischia are stouter, and the acetabulum is also stout and well buttressed by all three elements. The femur is long and relatively slender; its head and greater and lesser trochanters are large. The third trochanter is narrow and elongate, and is situated about as far below the lesser as that tro- chanter is beneath the near-spherical head. The neck is short but distinct. The shaft is quite straight and the distal condyles are prominent. Tibia and and fibula are both very elongated as can be seen on CM 9386 (fig. 5D) and PM 39371 (fig. 4). The fibula is a straight slender strut with expanded proximal (complete only on PM 3937 1) and distal articular ends. Shafts of the two bones are sepa- rated from one another for about two-thirds of their length proximally, united distally. That of the tibia is stout, slightly sinuously curved so that in the proximal half the anterior edge is convex, in the distal half concave. The proximal articu- lation is triangular with facets for lateral and me- dial condyles. There is a prominent cnemial crest. Fio. 9. A-l, A series of mandibles of Protoptychus hatcheri showing variations in the population. Specimens shown are: A, PM 8009. B, PM 8010. C, PM 8006. D, PM 801 1. E, PM 2301. F, PM 2323. G, PM 2312. H, PM 2319. I, PM 2324. All are shown approximately *6. TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 23 Eg - X I I I I I I I I I I I I I I I I I I I I I t» ■» 00 00 — I no n© fl r-~ oo r- m ~ o d ~ ~ ci d I A A A l A A fNOOO — O O — • f*» in on ■^■td- I I I I O on i-~ n ^ d d •*' d — i d — ' — «-i ; a ■9 8 a 5 — 1 B u 2 2 4= « 5 43 ur ngth eatest proxi head to troc stal width i/fibula leng us, metatars troproc. call eta tarsals tTc > > | g E 43 00 3 2 U c gJ35"SSS<2S J hh >•» ' 3 E 43 ■3 i? 24 FIELDIANA: GEOLOGY n ! si »g»« » o> * oo w> — -o >» o in r- mm^ oonw - — — * © © — © d — ' ricid i o> in — — © © — — © d 8r--« t^ w% oo — in O O riddd -dd-ridd IN — — — IN IN IN — IN n ■* ^ ^ ^ oo oo 00 V » t iC d «ni W» — i 0> r- r» so o oo o dd»i«dw d — — — o o * >o o m A o o — o «« A ^ © r» «n « — in r- >o iw-ioo m r— *mMfto> oo * i i»i — in d d t t d - d— -~ "• r- w^ m *o "^ r- f> r"i <*> in 00 vO 00 -CO- — d n'dd dd» d — 1— — oo m m Ml — fl ON | *r o 1 1 ""! °° IN l-» odd < d — ' * O 00 IN l~ l~- * IN mgi vi — I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I *> I I I I I I I I I + I I I I I I 2 | | | | | | | | | 11 5 n -J 0 t/) & a -J a. C 5 B. Iff llil|l|if IN m W> TURNBULL: PROTOPTYCH US HATCHERI SCOTT, 1895 25 h*3 ll*8 ilia as * U. 00 s? _ _ O — — © O 1/1 fN in — Tf 00 VO © oooisn Tf © © VI w> © — | oo W © — ©' — I © — — ^ oo © — © v-> w> r-~ O © c> m O — © 1 -©' — ©do —'do I I I I I I I I I I I ro ^ ,i 1 oo — I I *1"1 I I I I I _• ©• vo 2 5 >n i — r~ © — © I I I II I I I I S3 vo _' _; o © — © © — • fN © © — i i i i o © vo Ov p 3~ vo I 1- 7 c> © © u"i vo e oo "aw a -a - U t. O c JS — — o -r J3 § 3 T3 13 J= C u ■S co 1 wid idth :ngth gth lecra farti ectoral gird Total artic Scapula Length Greatest Spine to Spine to i E 8 c Prcxima Distal wi Radius It Ulna len Length o Length o g £ "2 c ■a <* 60 — •S H s I i ! ab « ^ ■S eo - E O £: X! S 2 a2|«S u MS US* «• 3 C P fi to ^J 3 bSo sis M > > > s BUS oj 5'? .. E ^J- 3 E 26 FIELDIANA: GEOLOGY Table 6. Status of vertebrae and ribs of specimens of Protoptychus. PM 8013 PM8018 PM 39834 PM 39371 CM 9386 Vertebra rerte- Left Verte- Right verte- Left Verte- Right Left Verte- KiKht number bra rib bra rib bra rib bra rib rib bra rib Cervical 1 X X __ 2 X X 3 b b — 4 b b 5 b b — 6 b b — 7 b b - Thoracic 1 X b b b b X _ 2 X b b b b X _ _ 3 X b b b b X _ _ 4 X b X b b X _ — 5 X b X b b X _ — 6 X b X b b X _ _ 7 X X X b b X _ 8 X X X b b X _ _ 9 b X X b b X _ _ — 10 b X X b b — _ _ 11 X b _ 12 X b _ 13 X b - Lumbar 1 X b 2 X b X 3 X X — 4 X X X 5 ? X — 6 ? X X 77 ? X X Sacral 1 X — _ X X 2 X — X X X 3 X — — 7 X ?4 ? - - ? ? Caudal 1 — ? X 2 — ? X 3 — ? X 4 — — X 5 — _ X 6 — — X 7 to end — X — plus 2 posterior, uncertain position X, elements known to be preserved; x, those represented by an impression, or an unidentified bone in the expected position of the indicated element; b, buried but presumed to be present; — , missing element; ?, uncertainty as to whether or not a usual element is actually present in Protoptychus, or may be represented by a number larger than the usual number in rodents. The six caudal vertebrae of CM 9386 were originally thought to be 1-6 but arc now considered to be farther back in the tail, about 7-1 1 . TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 27 The distal articular surfaces of both tibia and fibula are hidden, partly buried, and in articulation with astragalus and calcaneum. The astragalus is small and compact, the calcaneum also except that its tuberosity is quite large. The other tarsals are pres- ent, mostly in articulation, in all three skeletons. The metatarsus is enlarged, with all of the main toes involved, not just that of digit 3, which is only slightly longer and more massive than those of digits 2, 4, and 5. The pollex is shorter than the others, best seen in PM 8018, being about a third the length of the others. In this regard it differs from the condition of the most specialized of the species ofJaculus, in which the central metatarsal has taken over completely to become a functional cannon bone. Discussion The many parallels of anatomical features be- tween jerboas, kangaroo rats, and Protoptychus combine to define a distinctive life niche charac- terized by bipedal hopping and by marked direc- tional changes. This ricochetal motion serves re- markably well as a means of escape from predators, and as far as we can tell the first rodent to develop these specializations was Protoptychus in late Mid- dle Eocene time, about 44 to 45 million years ago (Berggren et al., 1985). Scott (1895) clearly rec- ognized its hopping potentialities from the few, but significant, remains that he had: the skull with its enlarged and inflated bullae. Even lacking the postcranial skeleton he felt confident with his as- signment of it as an ancestral form of the Dipod- idae, possibly related to the ancestry of the Het- eromyidae as well. Had he known the postcranial skeleton as we do now, doubtless that opinion would have been reinforced, for like the bullae, the limb and body proportions correspond very closely to those of modern kangaroo rats and jer- boas. In them all the very greatly lengthened hind limb is the common feature. Differences among them result from which segment(s) of the limb are lengthened the most. Wahlert (1973) succinctly reviewed the taxo- nomic history of Protoptychus to that date and in his detailed discussion he systematically consid- ered possible relationships to a number of rodent groups, especially Mysops and others within the Paramyidae (sensu lato). He concluded that on cranial features and dental evidence Protoptychus could be ruled out of close relationship to any rodent except some paramyids and Mysops among the protrogomorphs, and caviomorphs. His ar- gument for caviomorph ancestry is complex, and I think possible but rather unlikely. The problem is that assignment to a primitive group does not tell us much about where a line is headed, and there are no strong indications for relationship to any more specialized groups. I wonder if it is not time to reconsider a rela- tionship of Protoptychus to the Dipodidae as a possibility. I find no real conflict with having the Dipodidae arise from the Ischyromyidae (or Par- amyidae) either directly or via the Sciuravidae (Wilson, 1949; Wood, 1959). It is easy to derive the dental morphology of Protoptychus from that of either family. The dental morphological gap came later. Clearly the dental evidence aligns Pro- toptychus with the Ischyromyoidea, the earliest and most generalized of the rodent groups (Wood, 1935, 1937, 1959), so why not bring the dipodid line from its protrogomorph ancestor through the Protoptychidae, as Scott (1895) originally suggest- ed? Wahlert (1973) dismissed any myomorph ro- dent relationship for Protoptychus, "because the cheek tooth cusp pattern is essentially different." Generally that is true, but in as much as the pattern in Protoptychus is only slightly evolved beyond that of the protrogomorphs, which has to have been the base for both Protoptychus and the my- omorphs, that dismissal is not convincing to me. From my comparisons of the cheek teeth, I believe it possible to derive the Jaculus form from that of Protoptychus. Furthermore, Wahlert (1973) con- sidered the stapedial artery to be absent, but I find its foramen precisely in the same position in Jacu- lus and Protoptychus. This evidence plus the fun- damental similarity of the infraorbital foramen in both taxa, in addition to the apparently closely similar, highly specialized bullae and the shared saltatorially specialized body proportions, leads me to think that Scott's conclusion was probably correct as far as a dipodid relationship of Protop- tychus is concerned. But his notion of a relation- ship to the Heteromyidae, or Schlosser's (1924) to the Geomyoidea have proven to be wrong: Wood (1935) discredited any close geomyoid relation- ship on dental evidence, and Wahlert (1973), by showing Protoptychus to be hystricomorphous to a degree, put to rest any notion of a sciuromorph relationship. From all of this I conclude that Pro- toptychus and its family belong within the My- omorpha in a position linking the portion of that group which contains the Dipodidae with its an- 28 FIELDIANA: GEOLOGY Fra. 1 1. Diagrammatic representation of limb and tail proportions in Protoptychus and some comparative spec- imens. An ancestral protrogomorph is shown in A, two modern highly specialized ricochetal forms in C and D. and two non-hopping, more generalized modern forms in E and F. A, Paramys delicatus. B, Protoptychus hatcheri. C, Dipodomys sp. D, Jaculus blanfordi. E, Mus musculus LAC gray strain. F, Sciurus vulgaris. Not to scale; instead adjusted so that all pelvic lengths are approximately equal. cestral protrogomorph stock, somewhere within the Ischyromyoidea. Figure 1 2 expresses the gen- eral set of relationships of this conceptual frame- work. In Figure 12A the primitive, generalized protrogomorphous condition is shown to give rise to the various specialized conditions: sciuromor- phous, hystricomorphous, and myomorphous. The degree to which the latter shares in developing the primary attributes (Zygomatic Plate and I.O.F.) is indicated by the overlapping patterns. In Figure 1 2B this is translated into a hypothetical phytog- eny, modified from that presented by Wood in 1959. Conclusions The anatomy, especially that of the jaws and most of the postcranial skeleton, is now known to a fair degree. Previously only the skull and upper dentition had been known. It suggests an agile an- imal with a ricochetal hopping gait. The skull with its enlarged infraorbital foramina is hystricomor- phous at a myomorph level of expansion of that foramen, and the jaws are weakly hystricogna- thous. The dentition is closest to the condition in protrogomorphs. The auditory bullae are greatly expanded with three chambers visible externally: a large open mastoid chamber anterodorsally, an- other large open chamber posterodorsally and pos- teriorly that probably is formed by the exoccipital or possibly also by the mastoid, and an enlarged tympanic chamber proper. Sutures are indistinct so that one cannot be certain on this point. Details of the interior of the bullae are few. Other than the generally open condition of the two upper chambers, we cannot tell whether there are any septa other than the major ones visible from the exterior. These structures are all too small and delicate to permit further preparation. Lumbar, sacral, and anterior caudal vertebrae TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 29 dipodoid rodents (genera Zapus, Napaeozapus, Sicista and Jaculus). Miscellaneous Publications Museum of Zoology, University of Michigan, 124: 1-100. Krishtalka, L., R. K. Stucky, R. M. West, M. C. McKenna, C. C. Black, T. M. Bown, M. R. Dawson, D. J. GOLZ, J. J. FLYNN, J. A. LlLLEGRAVEN, AND W. D. Turnbull. 1987. Eocene (Wasatchian through Duchesnean) biochronology of North America, pp. 77-1 17. In Woodburne, M. O., ed., Cenozoic Mam- mals of North America, Geochronology and Biostra- tigraphy. University of California Press, Berkeley, Los Angeles, London. Lyon, M. W., Jr. 1 90 1 . A comparison of the osteology of the jerboas and jumping mice. Proceedings of the U.S. National Museum, 23: 659-668. Patterson, B. D., and R. M. Timm, eds. 1 987. Studies in Neotropical Mammalogy: Essays in Honor of Philip Hershkovitz. Fieldiana: Zoology (New Series), 39: 1- 506. Roehler, H. 1973. Stratigraphy of the Washakie For- mation in the Washakie Basin, Wyoming. U.S. Geo- logical Survey Bulletin 1369: 1-40. Schlosser, M. 1924. In von Zittel, K. A., ed., Sau- getiere. Grundziige der Palaontologie, II Abt. Roden- tia. Mylagaulinae. Geomyoidea. Anomaluroidea etc. p. 511. R. Oldenbourg, Munich and Berlin. Scott, W. B. 1895. Protoptychus hatcheri, a new ro- dent from the Uinta Eocene. Proceedings of the Acad- emy of Natural Sciences of Philadelphia, pp. 269-286, 6 figs. Turnbull, W. D. 1970. Mammalian masticatory ap- paratus. Fieldiana: Geology 18(2): 147-356, figs. 1- 48. . 1978. The mammalian faunas of the Washakie and A. E. Woods, eds., The Mammalian Fauna of the White River Oligocene. Transactions of the American Philosophical Society (New Series), 28: 155-269. 1959. Eocene radiation and phylogeny of the Formation, Eocene Age, of southern Wyoming. Part I, Introduction: The geology, history and setting. Fieldiana: Geology 33(30): 569-601, figs. 1-3, pis. I-V. Wahlert, J. H. 1973. Protoptychus, a Hystricomor- phous Rodent from the Late Eocene of North Amer- ica. Breviora, 419: 1-14, 2 figs. . 1974. The cranial foramina of protrogomor- phus rodents; an anatomical and phylogenetic study. Bulletin of the Museum of Comparative Zoology, 146(8): 363-410, figs. 1-13. Wilson, R. W. 1937. Two new Eocene rodents from the Green River Basin, Wyoming. American Journal of Science Series 5, 34: 447-456, figs. 1,2. . 1949. Early Tertiary Rodents of North Amer- ica. Carnegie Institution of Washington Publication, Contributions to Paleontology, 584(Part IV): 67-164. Winge, H. 1 94 1 . The Interrelationships of the Mam- malian Genera, vol. II. Rodentia, Carnivora, Pri- mates. C. A. Reitzels Forlag, Kobenhavn. pp. 1-376. [From "Fossil and Living Rodents (Rodentia) from Lagoa Santa, Minas Gereas, Brazil, with a Review of the Interrelationships of the Rodents": E Museo Lund- ii, vol. 1, 1887 (1888), translated by E. Deichmann and G. M. Allen.] Wood, A. E. 1935. Evolution and relationships of the heteromyid rodents. Annals of the Carnegie Museum, 24: 73-262. . 1937. Rodentia. In Scott, W. B., G. L. Jepsen, rodents. Evolution, XIII(3): 354-361. 1962. The early Tertiary rodents of the family Paramyidae. Transactions of the American Philo- sophical Society (New Series), 52: 1-261, figs. 1-91. . 1974. The evolution of the Old World and New World Hystricomorphs. Symposia of the Zoological Society of London, 1974(34): 21-60. Appendix The following materials are referred to Protop- tychus: PM 8018 and 39371 are the two nearly complete skeletons; PM 2309, 2310, and 8003 are left premaxillae with I, (G82293); PM 39833 is a right premaxilla with broken I; PM 8015B, 37377, 39827, 39828, and 39839 are left upper incisors; PM 39836 and 39895 are right upper incisors; PM 8007 and 8008 are edentulous left maxillae with alveoli or roots of P3-M3; PM 3738 1 and 39824 are edentulous left maxillary fragments with roots of P3-4; PM 39893 is a left maxillary fragment with P4- M2, and the alveolus of P3; PM 2084 and 39894 are left maxillary fragments with P4-M1; PM 2303 consists of a left M1-2, (G82303); PM 2306 and 2322 are left maxillary fragments with P4-M2 and alveolus of P3, the last with alveolus of M3, (G82301); PM 2304, 2325, and 8029 are left maxillae with P^M3, root of P3, except the last which has alveolus of P3, (G81974, G82298); PM 37373 is a left maxillary fragment with M2~3, roots of M1; PM 2302 is an edentulous right maxilla with al- veoli of P3-M'; PM 2307 is a right maxillary fragment with P3- M1; PM 2321 and 39898 are right maxillary fragments with P4 and alveoli of P3 and M1, (G82274); PM 8004 is a right maxillary fragment with P4- M2, root of P3; PM 37382 is a right maxilla with P3-M3; PM 37384 is a right maxilla with broken P3, and with P4-M2; 32 FIELDIANA: GEOLOGY PM 37385 is a right maxilla with P-M3, alveolus ofP3; PM 2301 and 2324 are left ramus fragments with P4-M„ broken I, alveoli of M2, (G81967); PM 2305 and 2323 are left ramus fragments with P4-M„(G81991); PM 2319 is a left mandibular ramus with M,_3, broken I, (G81976-G81978); PM 8009 is a left mandibular ramus with I, P4- M3; PM 8010 is a left mandibular ramus with broken I, P4-M2; PM 39829 is a left ramus fragment with broken M, and M2_3; PM 37374 is an edentulous left ramus fragment with alveoli of I, P4-M,; PM 8015A is a partial lower I; PM 8016 is the anterior half of a left lower molar; PM 2312 is a right ramus fragment with P4-M,, (G81972); PM 8006 is a right ramus fragment with P4-M3; PM 801 1 is a right ramus fragment with I, P4-M,; PM 37375 is a right ramus fragment with M,_2, alveoli of M3; PM 39832 and 39896 are right mandibular rami with I, P4-M2, the latter with alveolus of M3; PM 8005 is a right ramus fragment with M2.3; PM 39830 is a right ramus fragment with P4-M2; PM 2326 is a right ramus fragment with P4; PM 39831 consists of a right P4-M,; PM 2100 is a right M,; PM 37376 is a right lower molar, probably M3; PM 2088 is the distal end of a humerus; PM 39835 is the proximal Vs of a radius; PM 209 1 is the proximal end of an ulna; PM 2092 and 2094 are proximal ends of femurs; PM 8017, 39825, and 39838 are distal ends of femurs; PM 39837 is a fragment of a femur; PM 8013 is a partial sacrum; PM 39834 is a sacral vertebra. TURNBULL: PROTOPTYCHUS HATCHERI SCOTT, 1895 33 Field Museum of Natural History Roosevelt Road at Lake Shore Drive Chicago, Illinois 60605-2496 Telephone: (312) 922-9410