Mammalian Paleontology

Rodriguez-de la Rosa, Guzman-Gutierrez y Ortega-Hurtado 2011 A New Occurrence of Toxodonts in the Pleistocene of Mexico

by Jose Ruben Guzman-Gutierrez

Review of fossil pangolins (Mammalia: Pholidota) in respect to their phylogenetic relationships

by Georgia Maclean-Henry

An unpublished review

Faunal and palaeoenvironmental changes in the Çal Basin, SW Anatolia: Implications for regional stratigraphic correlation of late Cenozoic basins

by Serdar Mayda

Comptes Rendus Geoscience, in Press, 2012

A Mammalian Lost World in Southwest Europe during the Late Pliocene

by Guiomar Garrido

New records of Plio-Pleistocene koalas from Australia: palaeoecological and taxonomic implications

by Gilbert Price

Price, G.J., Zhao, J.-x., Feng, Y.-x., Hocknull, S.A., 2009. New records of Plio-Pleistocene koalas from Australia: palaeoecological and taxonomic implications. Records of the Australian Museum 61, 39-48.

Koalas (Phascolarctidae, Marsupialia) are generally rare components of the Australian fossil record. However, new... more Koalas (Phascolarctidae, Marsupialia) are generally rare components of the Australian fossil record. However, new specimens of fossil koalas were recovered during recent systematic excavations from several eastern Plio-Pleistocene deposits of Queensland, eastern Australia, including the regions of Chinchilla, Marmor and Mt. Etna. The new records are significant in that they extend the temporal and geographic range of Plio-Pleistocene koalas from southern and southeastern Australia, to northeastern central Queensland. We provide the first unambiguous evidence of koalas in the Pliocene Chinchilla Local Fauna (phascolarctid indet. and Ph. ?stirtoni): important additions to an increasingly diverse arboreal mammalian assemblage that also includes tree kangaroos. The persistence of koalas and local extinction of tree kangaroos in the Chinchilla region today suggests that significant habitat and faunal reorganization occurred between the Pliocene and Recent, presumably reflecting the expansion of open woodlands and grasslands. Other koala records from the newly U/Th-dated Middle Pleistocene Marmor and Mt. Etna fossil deposits (Phascolarctos sp. and Ph. ?stirtoni), along with independent palaeohabitat proxies, indicate the former presence of heterogeneous habitats comprised of rainforests, open woodlands and grasslands. The lack of such habitat mosaics in those regions today is likely the product of significant Middle Pleistocene climate change.

Plio-Pleistocene carnivoran guilds: Implications for hominid paleoecology

by Margaret Lewis

Lewis ME (1995) Plio-Pleistocene Carnivoran Guilds: Implications for Hominid Paleoecology. Ph.D. thesis. Department of Anthropology. State University of New York, Stony Brook, p 524

Carnivoran Paleoguilds of Africa: Implications for Hominid Food Procurement Strategies

by Margaret Lewis

Lewis ME (1997) Carnivoran paleoguilds of Africa: Implications for hominid food procurement strategies. J Hum Evol 32:257-288

Tool-using hominids, as carnivorous animals, would have been part of the various carnivore guilds present in... more Tool-using hominids, as carnivorous animals, would have been part of the various carnivore guilds present in Plio-Pleistocene Africa. Hominid dietary strategies must be understood within the larger context of carnivore behavior and ecology, as carnivorans could have affected the abilities of hominids to procure meat and/or marrow. The functional anatomy of extant and fossil
carnivorans was examined to infer behaviors in fossil carnivorans that would have impacted on hominid dietary strategies in terms of carcass availability. Comparisons of guild structure were carried out to examine changes in carnivoran interactions and their implications for hominid behavior. Plio-Pleistocene carnivorans engaged in a wider range of behaviors than modern carnivorans. The sabertoothed felids Dinofelis and Megantereon
probably did not provide much larger carcasses than modern species. Another sabertooth, Homotherium generated larger carcasses, but may have disarticulated and transported these carcasses. Fossil representatives of modern taxa may not have been equivalent ecologically within the carnivoran guild. Overall, hominids in eastern Africa probably had a greater range of scavenging opportunities than did those of southern Africa during the Plio-Pleistocene. Local and continent-wide extinction events in large-bodied carnivoran guilds from 1 to 2 Ma had a substantial effect on carcass availability and the risk to
hominid scavengers. These structural changes in the carnivore guild may have provided an opportunity for hominids to widen their niche with respect to dietary behavior.

The evolution of spotted hyenas (Crocuta)

by Margaret Lewis

Lewis ME, Werdelin L (2000) The evolution of spotted hyenas (Crocuta). Hyaena Specialist Group Newsletter 7:34-36

Carnivora From the South Turkwel Hominid Site, Northern Kenya

by Margaret Lewis

Werdelin L, Lewis ME (2000) Carnivora from the South Turkwel hominid site, northern Kenya. J Paleontol 74(6):1173-1180

A small collection of carnivoran fossils from the South Turkwel hominid site is described. The fauna is composed of... more A small collection of carnivoran fossils from the South Turkwel hominid site is described. The fauna is composed of Megantereon ekidoit new species, Homotherium sp., Crocuta cf. dietrichi, cf. Pachycrocuta sp., Canis new species A., cf. Civettictis sp., Viverridae or Herpestidae indet., and Lutrinae indet. The record of Megantereon and Canis, as well as Pachycrocuta and Civettictis, if these genera are identified correctly, represents the earliest occurrences of their respective taxa in Africa. These specimens suggest a relatively rapid reorganization of the carnivore guild some time around 3.5 Ma, followed by a longer period of transition to a fauna more comparable in composition to the modern one.

A revision of the genus Dinofelis (Mammalia, Felidae)

by Margaret Lewis

Werdelin L, Lewis ME (2001) A revision of the genus Dinofelis (Mammalia, Felidae). Zool J Linn Soc 132:147-258

This paper consists of a taxonomic and systematic revision of the extinct felid genus Dinofelis (Felidae,... more This paper consists of a taxonomic and systematic revision of the extinct felid genus Dinofelis (Felidae, Machairodontinae) and an analysis of its ecomorphology and evolution. Dinofelis has a broad distribution, with material from all northern continents and Africa, the latter of which was the apparent centre of evolution of the genus. We describe new material of Dinofelis from a number of sites in eastern Africa and reconsider all previously described
material. We name two new species and identify several other distinct species-level taxa but refrain from naming these due to a paucity of well-preserved material. At the same time, we synonymize the two named Asian species, D. cristata and D. abeli, of which the former has priority. There are few characters useful in systematic analysis, but we can suggest at least one migration from eastern to southern Africa. Ecomorphological analysis of both craniodental and postcranial characters suggests that Dinofelis in many respects converged on modern pantherine cats in morphology and behaviour, a trend culminating in the South African D. barlowi and the Asian D. cristata, which are the most pantherine-like of all machairodont felids. This trend is reversed in the evolution of the youngest
species, D. piveteaui, which is also the most machairodont in its ecomorphology. The timing of the extinction of Dinofelis is difficult to determine. Outside Africa material is scarce at all times, while in Africa the apparent extinction of Dinofelis at about 1.4 Mya coincides with the end of the good, semi-continuous fossil record present in eastern Africa from about 4Mya onwards. Dating of Kanam East (with D. piveteaui) to the Jaramillo Subchron (1.070–0.990 Mya) suggests possible survival considerably later. Thus, the extinction datum for Dinofelis cannot at present be firmly established.

Species identification in Megantereon: a reply to Palmqvist

by Margaret Lewis

Werdelin L, Lewis ME (2002) Species identification in Megantereon: A reply to Palmqvist. J Paleontol 76(5):931-933

PALMQVIST (2002) has criticized our attribution of the mandibular ramus of Megantereon from South Turkwel, Turkana... more PALMQVIST (2002) has criticized our attribution of the mandibular ramus of Megantereon from South Turkwel, Turkana Basin, Kenya, to a new species, M. ekidoit (Werdelin and Lewis, 2000), suggesting instead that it ‘‘unequivocally’’ belongs to the African species M. whitei. We believe that this criticism stems from a misunderstanding of our statements and from an erroneous view of variability within Megantereon. In this reply we shall address Palmqvist’s criticisms, showing that M. ekidoit is not synonymous with M. whitei, and also that the specific attribution of various Megantereon specimens is not as clear cut as Palmqvist (2002;Martinez Navarro and Palmqvist, 1995, 1996) believes.

Plio-Pleistocene Carnivora of Eastern Africa: Species Richness and Turnover Patterns

by Margaret Lewis

Werdelin L, Lewis ME (2005) Plio-Pleistocene Carnivora of eastern Africa: species richness and turnover patterns. Zool J Linn Soc 144:121-144

This paper presents an up-to-date and detailed overview of the Plio-Pleistocene fossil record of Carnivora in eastern... more This paper presents an up-to-date and detailed overview of the Plio-Pleistocene fossil record of Carnivora in eastern Africa. Major events in the carnivoran lineages present in the region are discussed and stratigraphic ranges of all species-level taxa are provided. The compiled data are used for quantitative analyses of species richness and turnover. Sampling is considered to be adequate for the interval 3.6–1.5 Mya, and poorer in the half-million-year time slices before and after this interval. Species richness peaks around 3.6–3.0 Mya and declines gradually from that time until the end of the time period analysed. Calculation of origination and extinction rates indicate that there are two peaks of origination: at 3.9–3.3 Mya (although the earlier half of this interval is biased through poor sampling) and at 2.1–1.8 Mya. The origination rate is zero in the interval 3.0–2.4 Mya. The extinction rate peaks at around 3.0 Mya after which it falls slightly, remaining nearly constant until 1.8 Mya, after which it increases considerably. The data support the hypothesis that the modern carnivoran guild of eastern Africa originated relatively recently, mostly within the last million years. There is no support in these data for a turnover pulse in Carnivora between 3
and 2 Mya.

Patterns of change in the Plio-Pleistocene carnivorans of eastern Africa: Implications for hominin evolution

by Margaret Lewis

Lewis ME, Werdelin L (2007) Patterns of change in the Plio-Pleistocene carnivorans of eastern Africa: Implications for hominin evolution. In: Bobe R, Alemseged Z, Behrensmeyer AK (eds) Hominin Environments in the East African Pliocene: An Assessment of the Faunal Evidence. Springer-Verlag, The Netherlands, pp 77-105

This paper uses changes in origination and extinction rates and species richness of eastern African carnivorans... more This paper uses changes in origination and extinction rates and species richness of eastern African carnivorans through time to discuss issues related to the evolution of hominin behavior. To address the question of which taxa were most likely to have had competitive interactions with hominins, modern carnivorans were sorted into size classes based on shifts in behavior, ecology, and body mass. Four size classes were created, among which the two largest (21.5–100 kg and >100 kg) include those taxa whose behavior is most relevant to the evolution of hominin dietary behavior. Fossil taxa were then assigned to these size classes. A summary of the temporal range and reconstructed behavior and ecology of fossil members of the two largest size classes is presented. We discuss the relevance of each taxon to reconstructing hominin behavior and suggest that hominins must have evolved not only successful anti-predator strategies, but also
successful strategies to avoid kleptoparasitism before carcass-based resources could become an important part of the diet. Although hominins were unlikely to have been top predators upon first entrance into the carnivore guild, effective anti-predator/anti-kleptoparasitism strategies in combination with the eventual evolution of active hunting would have increased the rank of hominin species within the guild. While the appearance of stone tools at 2.6 Ma has no apparent effect upon carnivorans, the appearance of Homo ergaster after 1.8 Ma may have been at least partly responsible for the decrease in the carnivoran origination rate and the increase in the extinction rate at this time. The behavior of H. ergaster, climate change, and concomitant changes in prey species richness may have caused carnivoran species richness to drop precipitously after 1.5 Ma. In this situation, even effective kleptoparasitism by H. ergaster may have been enough to drive local populations of carnivorans that overlapped with hominins in dietary resources to extinction.
Possibly as a result, the modern guild, which evolved within the last few hundred thousand years, is composed primarily of generalists. Although the impact of H. sapiens on the carnivoran guild cannot be assessed due to a lack of carnivoran fossils from this time period, one might not consider the modern carnivore guild to be complete until the appearance of our species approximately 200,000 years ago.

New species of Crocuta from the Early Pliocene of Kenya, with an overview of Early Pliocene hyenas of eastern Africa

by Margaret Lewis

Werdelin L, Lewis ME (2008) New species of Crocuta from the Early Pliocene of Kenya, with an overview of Early Pliocene hyenas of eastern Africa. J Vert Paleontol 28(4):1162-1170

A new species of Crocuta (spotted hyenas), Crocuta eturono n. sp., from the Early Pliocene of the Turkana Basin, Kenya... more A new species of Crocuta (spotted hyenas), Crocuta eturono n. sp., from the Early Pliocene of the Turkana Basin, Kenya is described. The species has been recovered from LO6S, a site in the Kataboi Member of the Nachukui Formation, on the western side of Lake Turkana. The site is dated to >3.4 Ma. The new species differs from all previously identified species of Crocuta in its length proportions of the cheek teeth, having a very long m1 and short p3 and p4. The species is also tentatively identified from the Tulu Bor Member of the Koobi Fora Formation, east side of Lake Turkana. The new species provides information for a discussion of the structure of the hyena guild in eastern Africa 4–3 Ma. Three groups of taxa are identified with distinct distributions. It is hypothesized that specific ecomorphologies of each group account for these distinctions.

Review of Dogs: Their Fossil Relatives and Evolutionary History

by Margaret Lewis

Lewis ME (2009) Dogs: Their Fossil Relatives and Evolutionary History. The Quarterly Review of Biology 84(3):315-316

The femur of extinct bunodont otters in Africa (Carnivora, Mustelidae, Lutrinae)

by Margaret Lewis

Lewis ME (2008) The femur of extinct bunodont otters in Africa (Carnivora, Mustelidae, Lutrinae). Comptes Rendus Palevol 7(8):607-627

This study compares fossil femora attributed to extinct African bunodont lutrines with extant mustelids and ursids to... more This study compares fossil femora attributed to extinct African bunodont lutrines with extant mustelids and ursids to reconstruct locomotor behavior. Due to the immense size differences among taxa, shape data were used to compare morphology. Based on morphological differences, the fossil femora are suggested to belong to different taxa with different locomotor abilities and habitat preferences. The Langebaanweg femur is the oldest and has a typical mustelid morphology suggesting that it was a locomotor generalist like most mustelids. The West Turkana form is more like extant nonbunodont otters, but much larger, and may have belonged to a semiaquatic taxon. The enormous Omo femur shares some features with truly aquatic taxa (e.g., Enhydra) and is the most likely to have been fully aquatic. The same may hold true for the Hadar species as it is most similar to that from the Omo. If these femora truly belong to bunodont lutrines, then they are more diverse in postcranial morphology than in dental morphology.

Interpreting sabretooth cat (Carnivora; Felidae; Machairodontinae) postcranial morphology in light of scaling patterns in felids

by Margaret Lewis

Lewis ME, Lague MR (2010) Interpreting sabretooth cat (Carnivora; Felidae; Machairodontinae) postcranial morphology in light of scaling patterns in felids. In: Goswami A, Friscia A (eds) Carnivoran Evolution: New Views on Phylogeny, Form and Function. Cambridge University Press, Cambridge, pp 411-465

Reconstructing the behaviour and ecology of extinct felids, especially that of machairodontine felids, has been of... more Reconstructing the behaviour and ecology of extinct felids, especially that of machairodontine felids, has been of great interest within the field of vertebrate paleontology. The anatomical design of these animals has been investigated with respect to dental function and prey acquisition behaviour, and, to a lesser degree, locomotion.

Few large felids exist today, and machairodontine felids were sometimes even larger than the largest extant felids, lions and tigers. This leads to the question of how much of the morphology observed in large machairodontines is simply an extension of size-related shape trends observed in modern felids. That is, to what extent are the morphological differences between machairodontines and smaller extant felids due to differences in size? Which extinct forms appear to be scaled-up versions of smaller felids, and which ones exhibit morphology indicative of functional differences?

This preliminary study investigates machairodontine postcranial morphology in light of scaling patterns in extant felids and examines how well trends in smaller extant felids predict the morphology of larger felids.We also look for any overall trends in machairodontine postcranial morphology that unite them
as a group, much like the possession of machairodont dentition does.

Creodonta

by Margaret Lewis

Lewis ME, Morlo M (2010) Creodonta. In: Werdelin L, Sanders WJ (eds) Cenozoic Mammals of Africa. University of California Press, Berkeley, pp 543-560

The order Creodonta was first named by Cope (1875) and removed from its original placement in the order Carnivora... more The order Creodonta was first named by Cope (1875) and removed from its original placement in the order Carnivora (Cuvier, 1822). Some researchers still maintain that creodonts
and carnivorans (or carnivoramorphans) are sister taxa (e.g., Tedford, 1976; Savage, 1977; Novacek and Wyss, 1986; Wozencraft, 1989; Flynn and Wesley-Hunt, 2005), though not all agree (Fox and Youzwyshyn, 1994; Polly, 1996). While both creodonts and carnivorans possess carnassials, creodont carnassials are either P4/M1 and m1/m2 (Oxyaenidae, limnocyonine hyaenodontids) or P4/M1/M2 and m1/m2/m3 (other Hyaenodontidae). Members of the order Carnivora all have carnassials at P4 and m1. While creodonts and carnivorans share an ossified tentorium and a few basicranial and tarsal features, their possible synapomorphies are few (Flynn et al., 1988; Wyss and Flynn, 1993; Rose, 2006).

Like carnivorans, creodonts vary greatly in their postcranial adaptations. Unlike carnivorans, most creodonts have fissured terminal phalanges, with the exception of the European Proviverrinae, and an unfused scaphoid and lunate. In general, hyaenodontid limbs are relatively short with respect to body size in comparison to carnivorans (Mellett, 1977), but more elongate and gracile than in the oxyaenids. A more general description of creodont craniodental and postcranial features can be found elsewhere (e.g., Jenkins and Camazine, 1977; Gingerich and Deutsch, 1989; Rose, 1990; Gebo and Rose, 1993; Polly, 1996; Gunnell, 1998; Morlo and Habersetzer, 1999; Morlo and Gunnell,
2003).

All known Afro-Arabian creodonts belong to the family Hyaenodontidae and range in age from the Eocene (and possibly Paleocene) to the middle Miocene. While the earliest African members of this family are found in the north, this family eventually spread southward into eastern and southern Africa. In Africa, as elsewhere, this family is diverse both in body size and morphology, with body size ranging from some of the smallest of forms to the largest hyaenodontid known (Megistotherium). A brief list of the Afro-Arabian hyaenodontid subfamilies and genera can be found in table 26.1, while the distribution of species can be found in tables 26.2 and 26.3 and, later, in figure 26.8.

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The chapter goes on to discuss all hyaenodontid fossils known from Africa at the time.

Carnivoran dispersal out of Africa during the early Pleistocene: Relevance for hominins?

by Margaret Lewis

Lewis ME, Werdelin L (2010) Carnivoran dispersal out of Africa during the early Pleistocene: Relevance for hominins? In: Fleagle JG, Shea J, Grine FE, Baden AL, Leakey REF (eds) Out of Africa I: The First Hominin Colonization of Eurasia. Springer, Netherlands, pp 13-27.

Carnivorans and hominins share a long history of interactions. This paper examines some of the evidence for carnivoran... more Carnivorans and hominins share a long history of interactions. This paper examines some of the evidence for carnivoran migration out of Africa at the same time as the earliest hominin dispersals. Of the two relevant taxa, Crocuta and Megantereon, Megantereon is the focus of this paper due to increased interest in this taxon in recent years and to the nature of the earliest records of dispersal of these two taxa, raising several questions related to Megantereon and its possible influence on hominins. To answer these questions, a brief summary of the literature on Megantereon in Eurasia and Africa is provided. While researchers do not agree on the number of species of Megantereon or the evolutionary relationships among those species, most would agree that Megantereon is a hypercarnivorous predator capable of grappling with relatively large prey for its body size. Despite the fact that carcasses generated by Megantereon were probably of value to hominins, the hypotheses that these carcasses were a major source of food or that they were a major force enabling hominins to migrate out of Africa are rejected. As indicated, in the literature on extant carnivorans, kleptoparasitism (=food theft) by dominant members of a carnivore guild exacts a heavy price on lower ranking carnivores. In addition, there is nothing in the African fossil record to suggest a special relationship between Megantereon and hominins that did not exist between hominins and other large-bodied carnivorans. The hypothesis that a species of Megantereon migrated out of Africa at roughly the same time as early hominins is also considered. While this hypothesis cannot be rejected, alternative hypotheses to explain similarities between later African and Eurasian forms of Megantereon are proposed (e.g., shared characters are due to convergence or are symplesiomorphies). In the end, the small number of diverse African species (including hominins) who disperse into Eurasia at the Plio-Pleistocene transition may have been part of a sweepstakes dispersal where the factors permitting (or driving) dispersal may have differed from species to species.

The stratigraphical position of Kemiklitepe fossil locality (Esme,Usak) revised: Implications for the Late Cenozoic sedimentary basin development and extensional tectonics in western Turkey

by Serdar Mayda