| VOLUME ( QH DECEMBER 1975 ISSN 0303-2515 INSTRUCTIONS TO AUTHORS 1. MATERIAL should be original and not published elsewhere, in whole or in part. When accepted, copyright becomes the property of the Trustees of the South African Museum. 2. LAYOUT should be as follows: (a) Masthead to consist of he Title: informative but concise, without abbreviations and not includingthe names of new genera or species Author’s (s’) name(s) ; Address(es) of author(s) (institution where work was carried out) Number of illustrations (figures, enumerated maps and tables, in this order) (b) Abstract of not more than 200 words, intelligible to the reader without reference to the text (c) Table of contents giving hierarchy of headings and subheadings (d) Introduction (e) Subject-matter of the paper, divided into sections to correspond with those given in table of contents (f) Summary, if paper is lengthy (g) Acknowledgements (h) References (i) Abbreviations, where these are numerous 3. 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For books give title in italics, edition, volume number, place of publication, publisher. For journal article give title of article, title of journal in italics (abbreviated according to the World list of Scientific periodicals. 4th ed. London: Butterworths, 1963), series in parentheses, volume number, part number (only if independently paged) in parentheses, pagination (first and last pages of article). Examples (note capitalization and punctuation) BULLOuGH, W. S. 1960. Practical invertebrate anatomy. 2nd ed. London: Macmillan. FISCHER, P.-H. 1948. Données sur la résistance et de le vitalité des mollusques.—J. Conch., Paris 88: 100-140. FISCHER, P.-H., DuvAL, M. & Rarry, A. 1933. Etudes sur les échanges respiratoires des littorines.—Archs Zool. exp. gén. 74: 627-634. Koun, A. J. 1960a. Ecological notes on Conus (Mollusca: Gastropoda) in the Trincomalee region of Ceylon.— Ann. Mag. nat. Hist. (13) 2: 309-320. Koun, A. J. 1960b. Spawning behaviour, egg masses and larval development in Conus from the Indian Ocean.— Bull. Bingham oceanogr. Coll. 17 (4): 1-51. THIELE, J. 1910. Mollusca: B. Polyplacophora, Gastropoda marina, Bivalvia. In: SCHULTZE, L. Zoologische und anthropologische Ergebnisse einer Forschungsreise im westlichen und zentralen Siid-Afrika 4: 269-270. Jena: Fischer.—Denkschr. med.-naturw. Ges. Jena 16: 269-270. (continued inside back cover) ANNALS OF THE SOUTH AFRICAN MUSEUM ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM Volume 69 Band December 1975 Desember Part 4 Deel CSS © UTUS vy M Le \ S Aly ony Quip NOVI Nas NOTES ON VARIATION IN PENGUINS AND ON FOSSIL PENGUINS FROM THE PLIOCENE OF LANGEBAANWEG, CAPE PROVINCE, SOUTH AFRICA By GEORGE GAYLORD SIMPSON Cape Town Kaapstad The ANNALS OF THE SOUTH AFRICAN MUSEUM are issued in parts at irregular intervals as material becomes available Obtainable from the South African Museum, P.O. Box 61, Cape Town Die ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM word uitgegee in dele op ongereelde tye na beskikbaarheid van stof Verkrygbaar van die Suid-Afrikaanse Museum, Posbus 61, Kaapstad OUT OF PRINT/UIT DRUK 1, 2(1, 3, 5, 7-8), 3(1-2, 5, t.-p.1.), 51-2, 5, 7-9), 6(1, t.-p.i.), 7-3), 8, 911-2), 10(1), 11(1-2, 5, 7, t.-p.i.), 24(2), 27, 31(1-3), 33 Price of this part/Prys van hierdie deel R2,00 Trustees of the South African Museum © Trustees van die Suid-Afrikaanse Museum 1975 ISBN 0 949940 79 8 Printed in South Africa by In Suid-Afrika gedruk deur The Rustica Press, Pty., Ltd., Die Rustica-pers, Edms., Bpk., Court Road, Wynberg, Cape Courtweg, Wynberg, Kaap NOTES ON VARIATION IN PENGUINS AND ON FOSSIL PENGUINS FROM THE PLIOCENE OF LANGEBAANWEG, CAPE PROVINCE, SOUTH AFRICA By GEORGE GAYLORD SIMPSON The Simroe Foundation, 5151 East Holmes Street, Tucson, Arizona 85711 (With 5 figures and 4 tables) [MS. accepted 25 June 1975] ABSTRACT Improved statistical data on limb bones of Recent Spheniscus demersus agree with previous suggestions that adaptively functional elements in penguins have comparatively slight variation. These data assist in the interpretation of isolated fossil bones. Additional specimens from the Pliocene of Langebaanweg indicate that Spheniscus predemersus Simpson, 1971, was incorrectly referred to Spheniscus, and the species is placed in a new genus, Jnguza. A second, larger species occurs at Langebaanweg, but available material does not warrant further identification or diagnosis. CONTENTS PAGE mtroductiont, a coe nmr e ioe eo hee tee. tee 9 Comparative data on variation in penguin limb bones . . 60 Eossilssirom)angebaanweger, | eeme aia) eee es eae OS Acknowledgements ie ee ie Re nee eS Su eel XA yagenees) SE aie et ae ie Ri N or uch: Gh ich oe nS, 1c: law INTRODUCTION These notes consist of two parts. First, a statistical study is made of some dimensions of limb bones of Spheniscus demersus, not only to increase the data for variation in penguins generally, but also and particularly to broaden the basis for sorting and identifying isolated and often incomplete fossil penguin bones. Next, the considerably enlarged suite of fossil penguin bones from Langebaanweg is studied. It is reasonably sure that many of these bones, and especially a partial but characteristic tarsometatarsus, belong to the species previously described as Spheniscus predemersus (Simpson 1971la). The tarsometatarsus excludes the species from Spheniscus and indicates reference to a hitherto unnamed and undefined genus. That genus is technically established later in this paper after the basis for its distinction and for the reference of predemersus to it has been established, but to simplify things the new combination Inguza predemersus will be used throughout. All fossil specimens here discussed are in the South African Museum. Reference numbers for all begin SAM-PQ-L, followed by a serial number, but for brevity they are here given only as L plus the number, which suffices for identification. 59 Ann. S. Afr. Mus. 69 (4), 1976: 59-72, 5 figs, 4 tables. 60 ANNALS OF THE SOUTH AFRICAN MUSEUM All measurements are in millimetres. Other conventions and abbreviations are explained as needed. COMPARATIVE DATA ON VARIATION IN PENGUIN LIMB BONES Many museums now have some osteological material of penguins, but few have samples of unified origin and large enough to give good estimates of population variation. The most nearly adequate statistical data are those in Simpson (1946) for specimens, mostly of Aptenodytes patagonicus, in the American Museum of Natural History, relatively few specimens, not sexed, and without precise locality data. Now better data can be given for another species, Spheniscus demersus, the African black-footed or jackass penguin. The population represented is that of Robben and Dyer Islands, one north- west and the other south-east of Cape Town. Although the islands are some distance apart, their penguin populations are essentially unified as birds banded on one may turn up on the other. The birds in this sample were caught in an oil- slick and taken for treatment by the South African National Foundation for the Conservation of Coastal Birds (SANCCOB) but failed to survive. (Many oiled birds do recover after treatment.) The dead birds were turned over to the South African Museum, where their wing and leg bones were macerated. The left limb bones are in that Museum, and the right limb bones of the same birds were kindly sent by Dr Q. B. Hendey to the Simroe Foundation for study by the author. It is conceivable that the sample is biased by the fact that these birds died from oiling, but that is improbable. There is no apparent reason why mortality of adult birds from oiling would be correlated with small differences in the sizes of their limb bones. Ten of the thirty birds involved are recorded as juvenile, and these were not included in the statistics even though some of them have apparently fully ossified limb bones. Three not recorded as juvenile do not have fully adult ossification and were therefore also excluded. One specimen consisted of wings only and was excluded because it is desirable to have wing and leg measurements all on the same individual. One more was disregarded because of poor preser- vation and one because of pathology (exostoses on some of the bones). Nineteen specimens were thus measured. Of these, five were recorded as males, one doubtfully. The doubtful specimen does happen to be smaller than the four certain males, but it was considered incorrect to exclude it from the sample on that account. The fourteen females measured are all recorded without question as to sex. The dimensions measured were selected primarily for their potential useful- ness in judging variation and proportions in single bones, especially in fossil specimens at hand. They are as follows: Humerus: a. Maximum longitudinal dimension. b. Width of shaft about one-third of distance distal to head. In this Species this is taken at the minimum width of the shaft. NOTES ON VARIATION IN PENGUINS 61 c. Width of shaft about two-thirds of distance distal to head. d. From the radial condyle to the longest distal process. Femur: a. From the hollow between the head and trochanter to that between distal condyles. 6. Proximal width. c. Distal width. Tibiotarsus: a. From the proximal articulation (excluding the crest) to the hollow between distal condyles. b. Distal width. Tarsometatarsus: a. Length on third metatarsal (proximal convexity to distal groove). b. Width of distal end of third metatarsal. c. Length on fourth metatarsal (to distal groove). The following statistics are given in Tables 1, 2 and 4: N —number of specimens. OR — observed range in sample. X —mean and siandard error. S —Standard deviation and standard error. VY -—coefficient of variation and standard error. The males of this living species are in general larger in mean sample esti- mates than the females, ‘humerus d’ being the only dimension of which this is not true. However the differences are slight and there is large overlap in all the observed ranges, still more in the probable population ranges. These bones in this species cannot be reliably sexed on the basis of size. The humerus is distinctly more variable in males than in females of this sample. That could be due to sampling error, but probably is not. Its functional significance, if any, is not clear. The tarsometatarsus is also somewhat more variable in males than in females, but here the difference is less and is quite probably due to sampling error. No sexual difference in variation is indicated for femur or tibiotarsus. The coefficients of variation are in general quite small. The mean of the 24 coefficients in Table | is only 3,63. The variation in functionally adaptive dimensions of birds tends to be low, suggesting that these characters are subject to effective stabilizing or centripetal selection. It is interesting that this is true of wing bones in penguins, aqueous fliers, as well as in aerial fliers. An aid to sorting isolated bones is provided by the ratios of measurements in associated bones of individuals of one species. Some data from the Spheniscus demersus sample are given in Table 2. There is no evident sexual distinction in this respect. These ratios are likely to be different in different species, but they probably will be close to those for S. demersus in species of approximately the same size. There is a tendency in Recent species, at least, for the humerus to be 62 ANNALS OF THE SOUTH AFRICAN MUSEUM TABLE 1 Statistics on Some Limb Bones of Spheniscus demersus N OR xX N) Vv. Males Humerus a 5 64,0-69,5 67,82 + 1,06 2,37 + 0,75 3,50 + 1,11 b 5 10,0-11,5 10,64 + 0,33 0,74 + 0,24 6,99 + 2,21 c 5 11,7-13,4 12,44 + 0,36 0,80 + 0,25 6,40 + 2,02 d 5 19,9-22,5 21,56 + 0,50 1,12 + 0,35 5,20 + 1,65 Femur a 5) 65,6-70,0 68,32 + 0,73 1,64 + 0,52 2,40 + 0,76 b 5 14,5-15,5 15,04 + 0,20 0,44 + 0,14 2,96 + 0,94 c 5 13,9-15,0 14,42 + 0,22 0,50 + 0,16 3,45 + 1,09 Tibiotarsus a 5) 96,7-104,4 101,16 + 1,28 2,87 + 0,91 2,84 + 0,90 b 5 13,1-14,3 13,86 + 0,21 0,46 + 0,15 3,33 + 1,05 Tarsometatarsus a 5 28,9-32,8 31,26 + 0,66 1,47 + 0,47 4,72 + 1,49 b 5 6,3-7,1 6,76 + 0,15 0,34 + 0,11 5,08 + 1,61 @ 5 26,0-28,5 27,22 + 0,44 0,98 + 0,31 3,61 + 1,14 Females Humerus a 14 63,9-69,3 66,66 + 0,51 191 = 0536 2,87 + 0,54 b 14 10,0—10,8 10,43 + 0,07 0,28 -- 0,05 2,64 + 0,50 Cc 14 11,3-12,7 11,94 + 0,09 0,35 + 0,07 ZTE OSS d 14 20,9-22,9 21,66 + 0,14 0,51 + 0,10 2,34 + 0,44 Femur a 14 61,9-68,9 65,94 + 0,43 1,61 + 0,30 2,44 + 0,46 b 14 14,1-15,5 14,79 + 0,12 0,44 + 0,08 SO Se OLS)7/ Cc 14 13,6-15,3 14,27 + 0,12 0,45 + 0,09 3,19 + 0,60 Tibiotarsus a 14 91,8-102,6 97,54 + 0,88 3,29 + 0,62 3,37 + 0,64 b 14 13,1-14,3 13,71 + 0,11 0,42 + 0,08 3,06 + 0,58 Tarsometatarsus a 14 28,9-32,8 30,79 + 0,28 1,05 + 0,20 3,39 + 0,64 b 14 6,5—-7,4 6,74 + 0,07 0,26 + 0,05 3,93 + 0,74 c 14 25,4-28,0 26,55 + 0,24 0,92 + 0,17 3,45 + 0,65 Symbols are explained in the text. TABLE 2 Ratios of Some Dimensions in Spheniscus demersus Humerus a Humerus a Femur a Femur a Tarsometatarsus a Tarsometatarsus a N OR N OR x N OR x WMRIES “5 S$ 6 6 8) USCSRO Mey Sy 25122015 21) 5 2,10—-2,27 | 29 Females 14 0,98-1,04 1,01 14 2,09-2,28 2,17 14 2,08-2,27 2,14 Symbols are explained in the text. longer relative to the femur and tarsometatarsus the larger the species (Simpson 1946: table 8). Since limb bones cannot be sexed by size in S. demersus and this is apparently usually but not necessarily always true in penguins, statistics were also calculated for some dimensions in a sample of S. demersus with the most NOTES ON VARIATION IN PENGUINS 63 probable ratio of males to females, that is, equal numbers of the two sexes. This includes the five males available and five females taken at random (using a table of random numbers applied to the serial numbers of these specimens). The dimensions were selected for comparison with available specimens of fossil humeri and femora from Langebaanweg. Results are given in Table 4. FOSSILS FROM LANGEBAANWEG Penguins from the Pliocene of Langebaanweg were previously described by the author (Simpson 1971a) on the basis of three humeri, one essentially com- plete and two fragmentary, a partial tibiotarsus, two complete femora, and one pedal phalanx. The humeri were referred to a then new species as Spheniscus predemersus (Fig. 1). It will be shown below that the generic ascription was almost certainly erroneous, and the name /nguza predemersus will be used here. Later discoveries have added greatly to the available materials, although even now they are not wholly adequate. Most of the bones of the wings and legs are represented, although some, unfortunately including the tarsometatarsus, only by imperfect specimens. The provenience is described in Hendey (1974) and Dr Hendey has added information in personal communication. The speci- mens are from the ‘E’ Quarry at Langebaanweg, and for the most part from the area designated as ‘East Stream’ (Hendey 1974: fig. 3). All are from the Vars- water Formation, and with one exception they are from “Bed 2’ of Hendey (1974: table 4), which he is now proposing to call the ‘Quartzose Sand Member’. That member is comprised of deposits accumulated in and adjacent to an estuary and its fauna is made up largely of terrestrial vertebrates. Besides the penguins, aquatic or amphibious elements are represented by an otter, Enhydriodon africanus, and a seal, Prionodelphis capensis. These are at present the only fossil penguins found in a predominantly non-marine association. The one exception referred to above is from the Gravel Member (=Bed 1), the basal unit of the Varswater Formation in which marine fossils are predominant. This deposit is the type of the proposed South African provincial land mammal stage and age Langebaanian, Pliocene in age and tentatively correlated with the Astian of Europe and the Rexroadian of North America (Hendey 1974: table 8). Renewed study of the systematics of these fossil penguins with enlarged samples is based on the humeri, femora, tibiotarsi, and tarsometatarsi. The other bones, although numerous, are less characteristic and do not add to con- clusions based on these bones. Measurements are given in Table 3. The dimensions are the same as those specified in the text above and used in Tables 1 and 2. Statistics derived from these measurements are given in Table 4 and there compared with statistics for a sample of Recent Spheniscus demersus made to include equal numbers of the two sexes, as noted in previous text. These dimensions, and therefore the measurements, differ somewhat from those previously used for the smaller sample (Simpson 197la: table 1). For ‘humerus b’ and ‘humerus c’ the co- 64 ANNALS OF THE SOUTH AFRICAN MUSEUM ILLIA LLV UU LLL LLL LIL LLL a4 113 114 15 116 117 Fig.1. Inguza predemersus, type, humerus SAM-—PQ-L6510. Ventral, dorsal and postaxial views. Scale in mm. NOTES ON VARIATION IN PENGUINS TABLE 3 65 Measurements of some Limb Bones of Fossil Penguins from Langebaanweg Specimen No. Dimension Humerus a b Cc d L6510, holotype of Inguza predemersus 59,0 8,6 10,0 17,8 L123010 7-5 9,6 10,9 18,9 L14853 . — 8,7 1 18,4 L12887A — 9,4 Wee 19,3 122952) — 10,0 IEA = 121928 . — 9,8 = = Femur a b Cc L23002 . 59,8 — 13,3 122983 . 61,5 — 13,4 ILPRAAUT/ See on cer, tao Wen 62,3 13,9 13,9 L122954 SO Riek Bsc ae — 14,4 — L12524A — — 14,5 13154 . dsl 18,1 16,3 13656" *. S — 17,6 L13066A — 18,7 — Tibiotarsus a b L23012 . 85,2 IES) 122950 . ca. 92 123} Tarsometatarsus a b Cc L23018 . DTD S63 24,2 L22974 . — 4,7 — 122985 . — ca. 74 — Symbols are explained in the text. TABLE 4 Some Statistical Data on a Sample with Equal Numbers of Males and Females of Spheniscus demersus and on Available Fossils from Langebaanweg Sample Dimension N OR x Spheniscus Humerusb 10 = 10,0-11,5 10,59 + 0,16 demersus Humerus c 10 = 11,7-13,4 12,24 + 0,16 Humerusd 10 = 19,9-22,5 21,63 + 0,25 Femur a 10 61,9-70,0 66,63 + 0,79 Femur c 10 13,6-15,0 14,19 + 0,14 Inguza predemersus Humerus 6 6 8,6-10,0 9,35 + 0,24 Humerus c 5 10,0-11,7 10,98 + 0,28 Humerus d 4 17,8-19,3 18,60 + 0,32 Femur a 3 59,8-62,3 61,20 + 0,74 Femur c 4 13,3-14,5 13,78 + 0,28 Mixed sample, all measureable bones from Langebaanweg Femur a 5 59,8-79,5 67,64 + 4,02 Femur c 6 13,3-17,6 14,83 + 0,71 Symbols are explained in the text. O55 =e 0519. 9,00 + 2,01 1,74 + 0,50 Vv 4,87 + 1,09 4,21 + 0,94 3472210383 3,76 + 0,84 3,12 + 0,70 Gul 66 ANNALS OF THE SOUTH AFRICAN MUSEUM efficients of variation are somewhat higher than for S. demersus or, so far as data are available, most other Recent penguins. However the difference is not great enough to indicate that it is probably not due either to sampling error or to somewhat greater real variability within a single species. For ‘humerus da’, generally a less variable dimension, V is not statistically different from that of S. demersus. Except for the moderate variation in these dimensions and in the ratios among them, these humeri do not differ appreciably in morphology. They are therefore all tentatively referred to Inguza predemersus, the more common but, as will now appear, not the only species of penguins in this fauna. There are seven tibiotarsi in the collection but only one is complete, and although three others are nearly so only one other gives approximate comparable measurements. The variation in size is considerable, but again not enough to indicate reliably that more than one species is represented. The two most complete specimens, L23012 and L22950, are within a size range appropriate for association with humeri referred to Inguza predemersus. The situation regarding the femora is quite different. For the six femora affording one or more useful measurements the coefficients of variation for all taken together are decidedly too high to be derived from a single species of penguins. It is also evident in Table 3 that they fall into two quite distinct size groups. The smaller group, L23002, L22983, L22117, L22954 and L12524A, is of appropriate size for association with the humeri referred to /nguza pre- demersus (Fig. 2). The ratio of the mean for ‘humerus a’ (two specimens) to the mean for ‘femur a’ (three specimens) is 0,95. In Spheniscus demersus it is 0,99 (Table 2), not significantly different. The femora L13154 and L3656 give a corresponding ratio of 0,75, which is significantly different, and these femora surely belong to a second, larger species, to which L13066 also belongs (Fig. 3). ‘Femur a’ for specimens referred to Jnguza predemersus has unusually slight variation and ‘femur c’ unusually large variation. However N is small for both (3 and 4, respectively), standard errors are correspondingly large, and the differences of values of V frorn those found in Spheniscus demersus are not significant. The specimen mentioned above as having come from the Gravel Member is L21628, the distal part of a femur. The end is too abraded or corroded for useful measurement, but this bone agrees closely with the larger specimens from the Quartzose Sand Member. Dr Hendey (pers. com.) notes that ‘The Gravel Member does include derived fossils, probably of Miocene Age’. It is, however, probable that this fragment represents the same species as the larger one in the overlying member. There are 16 partial tarsometatarsi in the collection, but most of these are scraps, especially distal condyles, from which little can be learned. The most extensive, L23018 (Fig. 4), includes the third and fourth tarsometatarsals and the dorsal, but not the plantar, part of the proximal end. The ratio for mean ‘humerus a@ of two Inguza predemersus to ‘tarsometatarsus a’ of this specimen is 2,14, which suggests that these animals were of quite closely the same size NOTES ON VARIATION IN PENGUINS 6 — ie l 6 1 Wi 5 1 114 ALIA IAIN 3 ] III 2 l i 1 Fig. 2. Inguza predemersus, femur SAM—-PQ-L22117. Anterior and posterior views. and very likely of the same species. L23401, a fourth tarsometatarsal with some adjacent bone, and L22974, most of a third tarsometatarsal with some adjacent bone, also may be referred to this species, to which most of the lesser fragments probably belong. There are, however, some scraps, notably L22985, the distal part of the third tarsometatarsal and some adjacent bone, and L23402, approxi- mately the same but even more poorly preserved, which belong to a definitely distinct and larger species (Fig. 5). The species could well be the same as that represented by the larger femora. On L23018 it can be determined that the medial intermetatarsal foramen (or inner proximal foramen of Zusi 1975) is larger than the lateral foramen and slightly more distal. It opens on the plantar side distal to the medial (inner) 68 ANNALS OF THE SOUTH AFRICAN MUSEUM Fig. 3. Spheniscidae indet. (left) and Inguza predemersus (right), femora SAM-PQ-L13154 and SAM-PQ-L22117. Anterior views. Borne (6 9 ter nemeancarnene Somme ———ee ee Cem SE « ©) ee get s pemenmenmnnel Ww 7—_—_—— ot aT —— =§ «) —mmm gue ————- S§« sO) I An Il NOTES ON VARIATION IN PENGUINS 69 = 6 I 8 1 1 7 I Fig. 4. Inguza predemersus, tarsometatarsus SAM—PQ-L23018. Dorsal and plantar views. calcaneal ridge. These characters definitely exclude reference to the genus Spheniscus in which the medial foramen is relatively smaller, is somewhat more proximal, and opens on the medial side of the medial calcaneal ridge. (See Zusi 1975, who shows that the latter arrangement occurs in Eudyptes; I have confirmed that it also occurs and is apparently invariable in Spheniscus demersus.) Among Recent penguins the genera Aptenodytes and Pygoscelis have the arrangement of intermetatarsal foramina more as in this fossil. The Recent species of those genera are decidedly larger than the fossil, even in Pygoscelts. The tarsometatarsus is also less elongate, the foramina relatively less proximal, 70 ANNALS OF THE SOUTH AFRICAN MUSEUM 8 1 7 mm 1 6 I > Fig. 5. Spheniscidae indet. (left) and Inguza predemersus (right), tarsometatarsi SAM-PQ-L22985 and SAM—PQ-L23018. Dorsal views. more nearly in a transverse line, and more nearly equal in size. Reference of the fossil to Pygoscelis or Aptenodytes is not tenable. It seems open to little question that the holotype humerus of /nguza prede- mersus, originally referred to Spheniscus, and the tarsometatarsus, now available and added to the hypodigm, belong to the same species and that the species neither belongs in nor was ancestral to Spheniscus. The humerus really differs little from that of Spheniscus demersus. Apart from smaller size, it has the shaft slightly more sigmoid and it lacks a preaxial angle or tubercle; it now follows that these slight differences are associated with a tarsometatarsus surely generically distinct from Spheniscus. They therefore now appear to be generic characters although that would hardly be tenable on the basis of the humeri alone. The author has been unable to find a previously named extinct genus to which this species can be reasonably referred. Duntroonornis from the early Oligocene of New Zealand may come as close as any, but its less elongate tarsometatarsus, smaller and more unequal foramina, and perhaps the obliquity of the metatarsals, if that is not caused by crushing of the only known specimen, distinguish it (see Simpson 19716). ‘Spheniscus’ predemersus must therefore be referred to a new, extinct genus which will now be formally proposed. It is improbable that this genus is ancestral or close to any living penguins, but it NOTES ON VARIATION IN PENGUINS 71 may conjecturally have some special relationship with Pygoscelis or perhaps even Aptenodytes. It is probably impossible and certainly inadvisable to identify or name the second, larger species from Langebaanweg on the basis of specimens now in hand. It is certainly distinct from Inguza predemersus, but the available specimens are otherwise not diagnostic. Technical validation of the new generic name and revision of the specific name follow. Order SPHENISCIFORMES Family Spheniscidae Inguza, gen. n. Etymology: ‘Inguza’ is given by McLachlan & Liversidge (1970) as a ‘native [South African] name’ for penguins. Greek derivatives appropriate for penguins have become rather overdone and repetitious. Native African languages do not have gender in the Latin sense, so this name is arbitrarily designated as masculine. Type-species: Spheniscus predemersus Simpson, 1971. Included species: Type only. Known distribution: Langebaanian, Pliocene, in the Quartzose Sand Member of the Varswater Formation at Langebaanweg, Cape Province, Republic of South Africa. Diagnosis: Humerus with shaft narrower proximally, somewhat sigmoid; tricipital fossa strongly bipartite; preaxial angulation absent. Tarsometatarsus elongate; intermetatarsal foramina proximal; medial foramen larger than lateral foramen, slightly more distal, opening distal to the medial calcaneal ridge on the plantar surface; third and fourth metatarsals straight. Inguza predemersus (Simpson, 1971) Spheniscus predemersus Simpson, 1971a: 1144. Etymology: Pre+- demersus, as older than known Spheniscus demersus and erroneously believed to be specially related to the latter. Holotype: SAM-PQ-L6510, left humerus, essentially complete. Present Hypodigm: The type and the following: L23010, complete humerus, L14853, L12887A, 122952, and L21928, partial humeri. L22117A, complete femur, L23002, L22983, L122954, and L12524A, partial femora. L23012, complete, and L22930, nearly complete, tibiotarsi. L23018 and L22974, partial tarsometatarsi. 2 ANNALS OF THE SOUTH AFRICAN MUSEUM Numerous other bones, mostly fragmentary, almost certainly belong to this species but have not yet entered explicitly into the present concepts and diagnoses of the genus and species. Known distribution: As for the genus. Diagnosis: Only known species of Jnguza. Measurements in Table 3. ACKNOWLEDGEMENTS I am greatly indebted to the South African Museum and to Dr Q. B. Hendey who provided the material for the study of variation in Spheniscus demersus, arranged the loan of the fossil specimens, gave some further information, and reviewed the manuscript of this paper. The study has been performed at the Simroe Foundation under the joint support from that foundation and the Department of Geosciences of the University of Arizona, Tucson, U.S.A. The illustrations are by Mr S. Kannemeyer of the South African Museum. REFERENCES HENDEY, Q. B. 1974. The late Cenozoic Carnivora of the south-western Cape Province. — Aun. S. Afr. Mus. 63: 1-369. McLACHLAN, G. R. & LiversipGE, R., revisers. 1970. Roberts birds of South Africa. Cape Town: Central News Agency. Simpson, G. G. 1946. Fossil penguins.— Bull. Amer. Mus. nat. Hist. 87: 1-99. Simpson, G. G. 1971a. Fossil penguin from the late Cenozoic of South Africa.— Science 171: 1144-1145. SIMPSON, G. G. 19716. A review of the pre-Pliocene penguins of New Zealand.— Bull. Amer. Mus. nat. Hist. 144: 319-378. Zust, R. L. 1975. An interpretation of skull structure in penguins.* Jn: STONEHOUSE, B., ed. The biology of penguins: 59-84. London and Basingstoke: Macmillan. *This study also refers to bones other than the skull. 6. SYSTEMATIC papers must conform with the International code of zoological nomenclature (particularly Articles 22 and 51). Names of new taxa, combinations, synonyms, etc., when used for the first time, must be followed by the appropriate Latin (not English) abbreviation, e.g. gen. n., sp. n., comb. n., syn. n., etc. An author’s name when cited must follow the name of the taxon without intervening punctuation and not be abbreviated; if the year is added, a comma must separate author’s name and year. The author’s name (and date, if cited) must be placed in parentheses if a species or subspecies is transferred from its original genus. The name of a subsequent user of a scientific name must be separated from the scientific name by a colon. Synonymy arrangement should be according to chronology of names, i.e. all published scientific names by which the species previously has been designated are listed in chronological order, with all references to that name following in chronological order, e.g.: Family Nuculanidae Nuculana (Lembulus) bicuspidata (Gould, 1845) Figs 14-15A Nucula (Leda) bicuspidata Gould, 1845: 37. Leda plicifera A. Adams, 1856: 50. Laeda bicuspidata Hanley, 1859: 118, pl. 228 (fig. 73). Sowerby, 1871: pl. 2 (figs 8a—b). Nucula largillierti Philippi, 1861: 87 Leda bicuspidata: Nicklés, 1950: 163, fig. 301; 1955: 110. Barnard, 1964: 234, figs 8-9. Note punctuation in the above example: comma separates author’s name and year semicolon separates more than one reference by the same author full stop separates references by different authors figures of plates are enclosed in parentheses to distinguish them from text-figures dash, not comma, separates consecutive numbers Synonymy arrangement according to chronology of bibliographic references, whereby the year is placed in front of each entry, and the synonym repeated in full for each entry, is not acceptable. In describing new species, one specimen must be designated as the holotype; other speci- mens mentioned in the original description are to be designated paratypes; additional material not regarded as paratypes should be listed separately. The complete data (registration number, depository, description of specimen, locality, collector, date) of the holotype and paratypes must be recorded, e.g.: Holotype SAM-A13535 in the South African Museum, Cape Town. Adult female from mid-tide region, King’s Beach, Port Elizabeth (33.51S, 25.39E), collected by A. Smith, 15 January 1973. Note standard form of writing South African Museum registration numbers and of date. 7. SPECIAL HOUSE RULES Capital initial letters (a) The Figures, Maps and Tables of the paper when referred to in the text e.g. *... the Figure depicting C. namacolus...’ “,..1in C. namacolus (Fig. 10)...’ (b) The prefixes of prefixed surnames in all languages, when used in the text, if not preceded by initials or full names e.g. Du Toit but A. L. du Toit Von Huene but F. von Huene (c) Scientific names, but not their vernacular derivatives e.g. Therocephalia, but therocephalian Punctuation should be loose, omitting all not strictly necessary Reference to the author should be expressed in the third person Roman numerals should be converted to arabic, except when forming part of the title of a book or article, such as ‘Revision of the Crustacea. Part VIII. The Amphipoda.’ Specific name must not stand alone, but be preceded by the generic name or its abbreviation to initial capital letter, provided the same generic name is used consecutively. SMITHSONIAN INSTITUTION LIBRARIES OTA 3 9088 01206 6320 ~GEORGE GAYLORD SIMPSON NOTES ON VARIATION IN PENGUINS AND ON FOSSIL PENGUINS FROM THE PLIOCENE OF LANGEBAANWEG, CAPE PROVINCE, SOUTH AFRICA