Sex determination in Miocene catarrhine primates

Canines of fossil hominoids and primitive catarrhines from several early, middle, and late Miocene sites were analyzed according to the shape indices described in Kelley (1995) and compared to those of males and females of extant great apes. In bivariate plots of the fossil canines utilizing the indices, 90% of the upper canines and 85% of the lower canines fell within or just outside the exclusively male or exclusively female territories delimited by the extant great apes. The remainder fell in the male-female overlap zones. Sex assignments based on these distributions were nearly 100% concordant with classifications according to canine height, suggesting a high degree of accuracy. There were various taxon-specific shifts in bivariate space among fossil genera, reflecting subtle differences in canine shape between taxa within the overall pattern of similarity to extant great apes as a whole. In many cases these shifts are matched by particular extant-ape species and subspecies, while other fossil taxa have no exact analogue for canine shape among the extant great apes. However, the pattern of spatial segregation of canines identified as either male or female at each of the sites largely mirrors that of males and females within the extant-ape sample, indicating that Miocene catarrhines shared with extant great apes a common pattern of shape differences between male and female canines, regardless of taxonspecific morphologies. These observations demonstrate that the canines of fossil catarrhines can be sexed with a high degree of confidence based solely on intrinsic features of shape. This will permit more reliable characterizations of morphological sexual dimorphism among fossil species. It is also argued that canine shape is a more reliable indicator of sex in fossil taxa than are canine/molar size ratios. © 1995 Wiley-Liss, Inc.     

A taxonomic revision of small dicynodonts with postcanine teeth

The validity of 18 genera of small (skull length less than 150 mm) dicynodonts with postcanine teeth has been assessed. It is concluded that only four genera, Emydops, Eodicynodon, Robertia and Pristerodon , can be defined satisfactorily on the basis of well-preserved and adequately prepared specimens. Of the remaining 14 genera, ten are not valid and may be accommodated within the four well-characterized genera. Three additional genera ( Chelyoposaurus, Koupia and Taognathus ) should become nomina nuda since they are based on inadequately diagnosed material which in the case of the first two genera is now lost. Brachyprosopus , although based on a single somewhat inadequate specimen, is also considered valid although future examination of the type (not seen by us) may require reassessment of this opinion.
We discuss briefly the nature of the taxonomic characters used, and the stratigraphic distribution of the four major genera.     

The response of catarrhine primates to pleistocene environmental fluctuations in East Asia

Examination of the patterns of distribution for five catarrhine genera (Gigantopithecus, Pongo, Hylobates, Macaca, andRhinopithecus) during the Pleistocene and Holocene in China indicates that the geographical ranges of individual genera shifted independently of one another in response to conditions of increasing seasonality. All genera examined saw their distributions shift southward, with the shifting subtropical and tropical zones, during the Pleistocene. This occurred earlier in the Pleistocene for the larger apes, and later for smaller forms. This apparent paradox is readily explained by the inability of large-bodied apes to satisfy the high metabolic demands of a relatively large brain as well as those of an absolutely larger body. Monkeys were somewhat less affected and their greater relative success is attributed to their abilities to survive in more highly seasonal environments by exploiting a wider variety of plant foods and to produce offspring more quickly, thanks to shorter gestation times and shorter interbirth intervals.     

Additional mandibles of Rangwapithecus gordoni,an early Miocene catarrhine from the Tinderet localities of Western Kenya

Two catarrhine mandibles and five isolated teeth have been discovered from Early Miocene localities in Western Kenya. One mandible comes from the well‐known locality of Songhor whereas the other is from a newly discovered locality, Lower Kapurtay, located near Songhor. The mandibles both can clearly be assigned to the species Rangwapithecus gordoni based on molar morphology, which is unique among Early Miocene catarrhines. The isolated specimens can be assigned to Rangwapithecus based on their similarities in morphology to the homologues preserved in the two mandibles. These specimens provide important new information about the dentognathic morphology of Rangwapithecus, which is described in detail. The mandible from Songhor (KNM‐SO 22228) represents the first definitive female mandible of Rangwapithecus. The Lower Kapurtay mandible (KNM‐KT 31234) appears to be male but is much smaller than another recently described male mandible of this species (KNM‐SO 17500) and the type maxilla (KNM‐SO 700). These specimens enable a reassessment of the attributions of all other mandibles and isolated lower teeth of Rangwapithecus, and we present a complete hypodigm of the mandibular and lower dental material for the species. Finally, we provide some additions to the diagnosis of Rangwapithecus gordoni based on previously unknown morphology. Am J Phys Anthropol 153:341–352, 2014. © 2013 Wiley Periodicals, Inc.     

Middle Miocene elasmotheriine Rhinocerotidae from China and Mongolia: taxonomic revision and phylogenetic relationships

Eight elasmotheriine rhinocerotid species have been described from the Middle Miocene of China and Mongolia. In this paper a revised taxonomy is presented based on direct observation and comparison of the available material. A phylogenetic analysis based on 282 morphological characters has led to the reappraisal of Procoelodonta Matthew, 1931, Caementodon Heissig, 1972 and Huaqingtherium Huang & Yan, 1983. The genus Procoelodonta is split into three subgenera: P.  ( Procoelodonta ) Matthew, 1931, P.  ( Begertherium ) Beliaeva, 1971, and P.  ( Pasalarhinus subg. n). The genus Caementodon is split into two subgenera: C.  ( Caementodon ) Heissig, 1972 and C.  ( Beliajevina ) Heissig, 1974. Four species are assumed to have occurred in the Middle Miocene within the area studied: Procoelodonta ( Procoelodonta ) mongoliense (Osborn, 1924), ' P. ' ( Begertherium ) borissiaki (Beliaeva, 1971), ' Caementodon ' ( Beliajevina ) fangxianense (Yan, 1979) and Huaqingtherium lintungense (Zhai, 1978) (=' Caementodon tongxinensis ' Guan, 1988 =' Huaqingtherium qiui ' Guan, 1993 =' Hispanotherium tungurense ' Cerdeño, 1996). Shennongtherium hypsodontus Huang & Yan, 1983 is removed from the Elasmotheriina, owing to dental characters which suggest that it is a teleoceratine. The distribution of the main characters later seen in Elasmotherium is briefly discussed. The persistence and diversity of the Elasmotheriina throughout the Middle Miocene help explain how minute brachyodont animals gave rise to the mammoth-sized hypsodont Elasmotherium.     

A new suiform (Artiodactyla,Mammalia) from the Early Miocene of East Africa

Fossils of an unnamed large suiform have been recovered from two Early Miocene localities in East Africa. The material is distinct from other species of the suborder, including the anthracothere Brachyodus aequatorialis, which is of similar size. The upper molars of the new form are bunodont, quadricuspidate (with a tiny paraconule), and have no buccal styles (parastyle, mesostyle, metastyle) and the enamel is thin and lightly wrinkled to smooth, which contrasts strongly with upper molars of Brachyodus which are pentacuspidate, selenodont, have pervasively wrinkled enamel and well-developed parastyle, mesostyle and metastyle. A new genus and species is erected for this suiform, which is most likely an anthracothere.     

Mechanisms of hominoid dispersal in Miocene East Africa

The thesis of this essay is that the ecological changes which occurred during the Miocene in East Africa, created both the need and the conditions for the development of dispersal behaviour and other adaptations. The major ecological change in East Africa during the Miocene was the break-up of the relatively homogenous, lowland, tropical rainforest. The forest break-up was due to the combined effects of climatic change and rifting. The result of the fragmentation for species adapted to the forest, was increasing resource limitation. Species responded either by retreating with the forests, becoming extinct, or by evolving or developing new behaviours to cope with the new environment. The focus of this paper is upon the development of dispersal as a behaviour pattern for locating patchy resources. An ecological model is advanced to explain the development of dispersal and to place it in the context of other competing evolutionary responses to the ecological changes of the Miocene. The anatomical evolution of the Old World monkeys and apes during the Miocene is looked at in terms of the model. Bovid evolution over the same period is also looked at as evidence of a broad, episodic turnover in response to the ecological changes. It is suggested that hominid bipedalism may also fit the model and may have evolved as an adaptation for dispersion.     

The phylogenetic relationships of the early catarrhine primates: a review of the current evidence

This paper presents a review of the evolutionary relationships of the early catarrhine primates. The first stage of the analysis involves the reconstruction of the inferred ancestral morphotypes of the major groups of extant anthropoids. The introduction of the fossil taxa into the phylogenetic scheme represents the second and final stage of the analysis. The results of this cladistic analysis suggests that: (1) the parapithecids are a specialized group of basal anthropoids, (2) Oligopithecus savagei may represent the earliest recognizable catarrhine, (3) Propliopithecus (= Aegvptopithecus) and Pliopithecus apparently represent the successive sister taxa to the modern catarrhines, (4) Dendropithecus and Proconsul are best regarded as basal catarrhines of modern aspect, and (5) Victoriapithecus is a primitive cercopithecoid monkey which represents the siter taxon of the extant Old World monkeys.     

A revision of the genus Drimiopsis (Hyacinthaceae) in East Africa

The following taxa of Drimiopsis (Hyacintheceae) are recognized for East Africa (Kenya, Tanzania, Uganda): D. barteri (2n=44), D. botryoides ssp. botryoides (2n=44, 55, 66), D. botryoides ssp. prostrata ssp. nov. (2n = 22), D. maculata and D . sp. A.     

A revision of the genus Drimia (Hyacinthaceae) in East Africa

The generic delimitation of Drimia and Urginea is discussed with special reference to flower and seed morphology (LM & SEM). The data support the joining of the two into one genus, Drimia. The following taxa are represented in East Africa (Kenya, Tanzania, Uganda): Drimia altissima, D. brachystachys comb, nov., D. calcarata comb, nov., D. congesta, D. elata, D. indica, D. macrocarpa sp. nov., and D. porphyrantha comb. nov.     

First hominoid from the Miocene of Ethiopia and the evolution of the catarrhine elbow

The first known fossil ape from the early-middle Miocene of Fejej, Ethiopia, is described here. The specimen, FJ-18SB-68, is a partial ulna from a locality dated by ⁴⁰Ar/³⁹Ar and paleomagnetic methods to a minimum age of 16.18 MYA. Compared to a variety of extant and fossil ulnae, FJ-18SB-68 is most similar to Turkanapithecus, Proconsul, and Pliopithecus, and appears to have been an arboreal quadruped with substantial forearm rotational mobility. Among the extant ulnae, canonical variates analysis successfully discriminates platyrrhines from catarrhines and within the latter, cercopithecoids from hominoids. Basal catarrhines (e.g., Aegyptopithecus) are platyrrhine-like in their morphology. Two basic trends appear to evolve from this generalized template: one with less mobile and more habitually pronated forearms, as seen in living and fossil cercopithecoids (including Victoriapithecus and Paracolobus), and another with greater forearm rotational mobility in fossil and modern hominoids. Primitive Miocene apes, including Proconsul, Turkanapithecus, and FJ-18SB-68, share with extant hominoids a more laterally positioned and laterally facing radial notch and an incipient trochlear keel. This morphology, along with a large insertion area for m. brachialis, suggests a departure from the more habitually pronated hand posture of monkeys and may indicate greater climbing abilities in these arboreally quadrupedal apes. Later Miocene apes, such as Oreopithecus and Dryopithecus share additional morphological features with hominoids, indicating considerable suspensory and climbing capabilities. Am J Phys Anthropol 105:257–277, 1998. © 1998 Wiley-Liss, Inc.     

The taxonomic status ofpraeanthropus africanus (primates: Pongidae) from the late pliocene of Eastern Africa

The taxonPraeanthropus africanus (Weinert, 1950), represented by the Garusi maxilla, is valid and reinstated. The morphological pattern of the Garusi maxilla is not that of a primitive hominid, but of a relatively generalized pongid. Since the apelike lectotype L.H.-4 and paralectotype A.L.200-1a ofAustralopithecus afarensis Johanson et al. 1978 are conspecific withP. africanus, and originate from the same formation, they are reassigned toPraeanthropus africanus.     

Revision of the Early Miocene Hyracoidea (Mammalia) of East Africa

Three genera of hyracoids were recorded from the Early Miocene of East Africa by Whitworth [18], but there has been considerable divergence of opinion about their status. Despite differences in cranial and dental morphology from Megalohyrax and Bunohyrax, Whitworth [18] classified two species in these genera that are recorded from much earlier deposits (Early Oligocene) in the Fayum, Egypt. One of his genera (Meroehyrax) was new. His classification has been the subject of debate, with some researchers [6,13] doubting the hyracoid status of one of his species (Bunohyrax sp), and changing the generic status of another (Megalohyrax championi). Meyer [6] recorded a fourth genus (Prohyrax) from Kenya, linking it to material from Namibia described by Stromer [16,17]. New samples of two hyracoid species collected by the Uganda Palaeontology Expedition throw light on their systematic position and taxonomy. It is concluded that there are three hyracoid genera (Afrohyrax, Brachyhyrax and Meroehyrax) in the Early Miocene deposits of East Africa, the first two of which are new. A fourth genus (Prohyrax) occurs in southern Africa, but is not reliably known from East Africa. To cite this article: M. Pickford et al., C. R. Palevol 3 (2004).

Résumé

Révision des Hyracoidea (Mammalia) du Miocène inférieur de l'Afrique de l’Est. Trois espèces d’Hyracoidea ont été signalées dans le Miocène inférieur d’Afrique orientale par Whitworth [18]. Malgré des différences importantes de la morphologie cranio-dentaire, deux des espèces kenyanes étaient classées dans Megalohyrax et Bunohyrax, genres connus dans les dépôts beaucoup plus anciens du Fayoum en Égypte. Le troisième genre décrit par Whitworth (Meroehyrax) était nouveau. La classification proposée [18] a été débattue ; certains auteurs [6,13] ont remis en cause le statut d’Hyracoïde d’une de ses espèces et ont modifié le statut générique d’une autre. Meyer [6] a signalé un quatrième genre (Prohyrax) au Kenya, sur la base des ressemblances avec le genre namibien décrit par Stromer [16,17]. De nouveaux spécimens récoltés par l’Uganda Palaeontology Expedition permettent d’éclaircir la position systématique et la taxonomie de deux des espèces. Nous concluons qu’il n’existe que trois genres d’Hyracoïdes dans les dépôts du Miocène inférieur d’Afrique orientale (Afrohyrax, Brachyhyrax et Meroehyrax), dont les deux premiers sont nouveaux. Par ailleurs, un quatrième genre (Prohyrax) est connu d’Afrique australe. Pour citer cet article : M. Pickford et al., C. R. Palevol 3 (2004).