A review of Theropithecus oswaldi with the proposal of a new subspecies.

Theropithecus oswaldi darti, as currently understood, is the oldest Theropithecus taxon in the fossil record and the earliest subspecies in the Theropithecusoswaldi lineage. Theropithecus oswaldi darti is typified at the site of Makapansgat in South Africa, and a similar form (T. o. cf. darti) is usually recognized at Hadar, Dikika, some Middle Awash localities, and Woranso-Mille in Ethiopia. This taxon is also tentatively believed to occur in Kenya at Kanam and Koobi Fora and in Member C of the Shungura Formation in Ethiopia. While there is a general consensus that the East African 'darti' specimens are sufficiently similar to each other, there has always been a question of whether they are too distinct from the South African type material of T. o. darti to belong to the same subspecies. Here we conduct a morphological comparison of the different samples previously assigned to T. o. darti and T. o. cf. darti. The results of our analyses overwhelmingly support the hypothesis that the East African samples are distinct from the South African ones, and they are likely distinct in geological age as well. Therefore, we propose a new subspecies designation for the material previously termed T. o. cf. darti from East Africa: Theropithecus (Theropithecus) oswaldi ecki subsp. nov. We also formally recognize Theropithecus (Theropithecus) oswaldi serengetensis (Dietrich, 1942) for specimens from Laetoli, Woranso-Mille, and perhaps Galili.

The naming of Homo bodoensis by Roksandic and colleagues does not resolve issues surrounding Middle Pleistocene human evolution.

Roksandic et al. (2022) proposed the new species name Homo bodoensis as a replacement name for Homo rhodesiensis Woodward, 1921, because they felt it was poorly and variably defined and was linked to sociopolitical baggage. However, the International Code of Zoological Nomenclature includes regulations on how and when such name changes are allowed, and Roksandic et al.'s arguments meet none of these requirements. It is not permitted to change a name solely because of variable (or erroneous) later use once it has been originally defined correctly, nor can a name be modified because it is offensive to one or more authors or to be politically expedient. We discuss past usage of H. rhodesiensis and the relevant nomenclatural procedures, the proposed evolutionary position of H. bodoensis, and issues raised about decolonizing paleoanthropology. We reject H. bodoensis as a junior synonym, with no value from its inception.

The radiation of macaques out of Africa: Evidence from mitogenome divergence times and the fossil record.

Fossil evidence indicates that numerous catarrhine clades of African origin expanded or shifted their ranges into Eurasia, among them macaques Macaca Lacépède, 1799. Macaques represent the sister taxon of African papionins and can thus be used as a model comparing an 'out-of-Africa' with an intra-African, e.g., baboons-Papio Erxleben, 1777 evolutionary history. The first step for such a comparison is to establish a well-resolved phylogeny of macaques with reliably estimated divergence times and to compare it with that of baboons and the fossil record. Therefore, we used mitochondrial (mtDNA) genome data deposited in GenBank of 16 out of 23 extant macaque species and of all six baboon taxa. We reconstructed phylogenetic trees using maximum-likelihood and Bayesian inferences and dated differentiation events using three fossil-based calibration sets. The obtained tree topology is in agreement with findings from earlier mtDNA studies, but yielded stronger nodal supports. We observed some para- and polyphylies in macaques and baboons, suggesting that ancient gene flow among divergent lineages has been common in both genera. Our divergence time estimates are in broad agreement with earlier findings and with the fossil record. Macaques started to diversify 7.0-6.7 Ma, followed by a stepwise radiation into several species groups in Asia, whereas baboons commenced diversification around 2.2 Ma. Accordingly, divergence of species groups and species in macaques clearly predates divergences in baboons. Based on our phylogenetic results with estimated divergence times and the recorded chronostratigraphic ranges of extinct macaque and baboon taxa, we compare the evolutionary radiations of both genera from paleobiogeographic and adaptive viewpoints.

Macaque remains from the early Pliocene of the Iberian Peninsula.

Macaques dispersed out of Africa into Eurasia in the framework of a broader intercontinental faunal exchange that coincided in time with the sea level drop associated with the Messinian Salinity Crisis. They are first recorded in Europe (Italy and Spain) by the latest Miocene, being subsequently recorded all over Europe, albeit sparsely, throughout the Pliocene and Pleistocene. These fossil European macaques are attributed to several (sub)species of the extant Barbary macaque (Macaca sylvanus). In Iberia, fossil macaques are best documented by Macaca sylvanus florentina from various Early Pleistocene sites, whereas their published Pliocene record is very scarce. Here we report the oldest post-Messinian occurrence of macaques in the Iberian Peninsula, based on the description and metrical comparisons of two upper teeth (a male canine and a third molar of two different individuals) from the early Pliocene (MN14, 5.0-4.9 Ma) site of Puerto de la Cadena (Murcia, SE Spain). The male C1 is fully comparable in morphology with those of extant and fossil M. sylvanus, and larger than those of Mesopithecus. The M3, in turn, displays the typical papionin morphology that characterizes the dentally-conservative genus Macaca-thereby discounting an alternate assignment to either the extinct colobine monkey Mesopithecus or the more dentally-derived papionin Theropithecus. Dental size and proportions of the M3 further support an attribution to an extinct subspecies of M. sylvanus instead of the larger papionin Paradolichopithecus. Mostly on biochronologic grounds, the two macaque teeth from Puerto de la Cadena are here assigned to Macaca sylvanus cf. prisca, albeit tentatively, given the lack of clear-cut criteria to distinguish this subspecies from the younger Macaca sylvanus florentina. The described material represents the oldest well-dated Pliocene record of macaques in Iberia, predating the record of Paradolichopithecus by almost 1.5 million years.

Evolution of the modern baboon (Papio hamadryas): A reassessment of the African Plio-Pleistocene record.

Baboons (Papio hamadryas) are among the most successful extant primates, with a minimum of six distinctive forms throughout Sub-Saharan Africa. However, their presence in the fossil record is unclear. Three early fossil taxa are generally recognized, all from South Africa: Papio izodi, Papio robinsoni and Papio angusticeps. Because of their derived appearance, P. angusticeps and P. robinsoni have sometimes been considered subspecies of P. hamadryas and have been used as biochronological markers for the Plio-Pleistocene hominin sites where they are found. We reexamined fossil Papio forms from across Africa with an emphasis on their distinguishing features and distribution. We find that P. robinsoni and P. angusticeps are distinct from each other in several cranial features, but overlap extensively in dental size. Contrary to previous assessments, no diagnostic cranio-mandibular material suggests these two forms co-occur, and dental variation at each site is comparable to that within P. h. ursinus, suggesting that only one form is present in each case. P izodi, however, may co-occur with P. robinsoni, or another Papio form, at Sterkfontein Member 4. P izodi appears more primitive than P. robinsoni and P. angusticeps. P. robinsoni is slightly distinct from P. hamadryas subspecies in its combination of features while P. angusticeps might be included within one of the modern P. hamadryas varieties (i.e., P. h. angusticeps). No definitive Papio fossils are currently documented in eastern Africa until the Middle Pleistocene, pointing to southern Africa as the geographic place of origin for the genus. These results have implications for Plio-Pleistocene biochronology and baboon evolution.

Evaluating causes of error in landmark-based data collection using scanners.

In this study, we assess the precision, accuracy, and repeatability of craniodental landmarks (Types I, II, and III, plus curves of semilandmarks) on a single macaque cranium digitally reconstructed with three different surface scanners and a microCT scanner. Nine researchers with varying degrees of osteological and geometric morphometric knowledge landmarked ten iterations of each scan (40 total) to test the effects of scan quality, researcher experience, and landmark type on levels of intra- and interobserver error. Two researchers additionally landmarked ten specimens from seven different macaque species using the same landmark protocol to test the effects of the previously listed variables relative to species-level morphological differences (i.e., observer variance versus real biological variance). Error rates within and among researchers by scan type were calculated to determine whether or not data collected by different individuals or on different digitally rendered crania are consistent enough to be used in a single dataset. Results indicate that scan type does not impact rate of intra- or interobserver error. Interobserver error is far greater than intraobserver error among all individuals, and is similar in variance to that found among different macaque species. Additionally, experience with osteology and morphometrics both positively contribute to precision in multiple landmarking sessions, even where less experienced researchers have been trained in point acquisition. Individual training increases precision (although not necessarily accuracy), and is highly recommended in any situation where multiple researchers will be collecting data for a single project.

Reassessment of Olduvai Bed I cercopithecoids: A new biochronological and biogeographical link to the South African fossil record.

Fossil monkeys have long been used as important faunal elements in studies of African Plio-Pleistocene biochronology, particularly in the case of the South African karst cave sites. Cercopithecoid fossils have been known from Tanzania's Olduvai Gorge for nearly a century, with multiple taxa documented including Theropithecus oswaldi and Cercopithecoides kimeui, along with papionins and colobines less clearly attributable to species. A small number of large papionin fossils, including a partial male cranium and partial female skull, have been previously identified as an early form of Papio, but noted as distinct from extant baboons as well as other fossil Papio species. In 2013 we reviewed the Olduvai cercopithecoid material at the National Museum of Tanzania, with a particular focus on the specimens from Beds I-IV. Quantitative and qualitative comparisons of the Olduvai papionins largely confirmed previous observations, with one notable exception. The large papionin taxon from Bed I previously recognized as Papio sp. is more properly recognized as Gorgopithecus major, a taxon previously known only from South Africa. Features shared between the Olduvai specimens and G. major include relatively short and concavo-convex tubular nasals, antero-posteriorly curved upper incisor roots, downwardly curved brow ridges in the midline, and robust zygomatic arches. The recognition of G. major at Olduvai Bed I, a well-known horizon with precise radiometric dates, provides an important biochronological and biogeographical link with South African localities Kromdraai A, Swartkrans Member 1 and possibly Swartkrans Members 2-3 and Cooper's A and D.

Cercopithecoid humeri from Taung support the distinction of major papionin clades in the South African fossil record.

Associated cercopithecoid postcrania are rare in the Plio-Pleistocene fossil record, particularly in the case of South African karst cave sites. However, as clear postcranial differences between major papionin clades have been documented, it should be possible to assign isolated papionin postcrania to the Cercocebus/Mandrillus and Papio/Lophocebus/Theropithecus groups wherever sufficient anatomy is preserved. Here, we demonstrate that two partial humeri preserved at Taung, UCMP 56693 and UCMP 125898, are most likely attributable to the Cercocebus/Mandrillus and Papio/Lophocebus/Theropithecus clades, respectively. Univariate analyses (ANOVAs and t-tests) and multivariate analyses (discriminant function analyses) of humeral features, combined with a phylogenetic analysis of 24 humeral characters, all support our assessment. Given that the overwhelming number of craniodental specimens at Taung are attributable to two papionin taxa, Procercocebus antiquus (a member of the Cercocebus/Mandrillus clade) and Papio izodi (a purported fossil species of the modern genus Papio), we assign UCMP 56693 to Pr. antiquus and UCMP 125868 to P. izodi with a high degree of confidence. Implications for cercopithecoid evolution and biogeography are discussed, with a particular emphasis on these two fossil taxa.

First record of Mesopithecus (Cercopithecidae, Colobinae) from the Miocene of the Iberian Peninsula.

We report dental remains of the extinct colobine monkey Mesopithecus from the Turolian (MN13, Late Miocene, ca. 6.23 Ma) locality of Venta del Moro (Valencia, Spain). They include most of the deciduous dentition and the unerupted germs of the first molars of a single infantile individual, as well as two lower left lateral incisors from two additional individuals. On the basis of morphometric comparisons, mainly based on the M1s, these remains are attributed to the Late Miocene species Mesopithecus pentelicus. They represent a significant addition to the knowledge of the deciduous dentition of this taxon, much less well-known than the permanent dentition. Although this genus was widely distributed from the Late Miocene through the Pliocene across Europe, southwestern Asia, Pakistan, and China, until now its occurence in the Late Miocene of the Iberian Peninsula had not been documented conclusively. Hence, the reported remains considerably enlarge southwestwards the known geographic distribution of Mesopithecus. The presence of this genus at Venta del Moro must be understood within the framework of the significant faunal turnover that took place in European faunas during the latest Turolian (the second Messinian mammalian dispersal), which is further documented at this locality by the occurrence of other eastern immigrants. At the same time, the presence of M. pentelicus at this site agrees well with previous paleoenvironmental and sedimentological evidence, indicating a lacustrine depositional environment with strong hydrologic seasonality.

The Hand of Cercopithecoides williamsi (Mammalia, Primates): Earliest Evidence for Thumb Reduction among Colobine Monkeys.

Thumb reduction is among the most important features distinguishing the African and Asian colobines from each other and from other Old World monkeys. In this study we demonstrate that the partial skeleton KNM-ER 4420 from Koobi Fora, Kenya, dated to 1.9 Ma and assigned to the Plio-Pleistocene colobine species Cercopithecoides williamsi, shows marked reduction of its first metacarpal relative to the medial metacarpals. Thus, KNM-ER 4420 is the first documented occurrence of cercopithecid pollical reduction in the fossil record. In the size of its first metacarpal relative to the medial metacarpals, C. williamsi is similar to extant African colobines, but different from cercopithecines, extant Asian colobines and the Late Miocene colobines Microcolobus and Mesopithecus. This feature clearly links the genus Cercopithecoides with the extant African colobine clade and makes it the first definitive African colobine in the fossil record. The postcranial adaptations to terrestriality in Cercopithecoides are most likely secondary, while ancestral colobinans (and colobines) were arboreal. Finally, the absence of any evidence for pollical reduction in Mesopithecus implies either independent thumb reduction in African and Asian colobines or multiple colobine dispersal events out of Africa. Based on the available evidence, we consider the first scenario more likely.

Metric and geometric morphometric analysis of new hominin fossils from Maba (Guangdong, China).

We present an analysis of a set of previously unreported hominin fossils from Maba (Guangdong, China), a cave site that is best known for the presence of a partial hominin cranium currently assigned as mid-Pleistocene Homo and that has been traditionally dated to around the Middle-Late Pleistocene transition. A more recent set of Uranium series dates indicate that the Maba travertine may date to >237 ka (thousands of years ago), as opposed to the original U-series date, which placed Maba at 135-129 ka. The fossils under study include five upper first and second molars and a partial left mandible with a socketed m3, all recovered from different parts of the site than the cranium or the dated sediments. The results of our metric and 2D geometric morphometric ('GM') study suggest that the upper first molars are likely from modern humans, suggesting a more recent origin. The upper second molars align more closely with modern humans, though the minimum spanning tree from the 2D GM analysis also connects Maba to Homo neanderthalensis. The patterning in the M2s is not as clear as with the M1s. The m3 and partial mandible are morphometrically intermediate between Holocene modern humans and older Homo sapiens. However, a minimum spanning tree indicates that both the partial mandible and m3 align most closely with Holocene modern humans, and they also may be substantially younger than the cranium. Because questions exist regarding the context and the relationship of the dated travertine with the hominin fossils, we suggest caution is warranted in interpreting the Maba specimens.

The nasal complex of Neanderthals: an entry portal to their place in human ancestry.

Neanderthals are one of the most intensely studied groups of extinct humans, as aspects of their phylogeny and functional morphology remain controversial. They have long been described as cold adapted but recent analyses of their nasal anatomy suggest that traits formerly considered adaptations may be the result of genetic drift. This study performs quantitative and qualitative analysis of aspects of the nasal complex (NC) in Neanderthals and other later Pleistocene fossils from Europe and Africa. A geographically diverse sample of modern human crania was used to establish an anatomical baseline for populations inhabiting cold and tropical climates. Nasofrontal angle, piriform aperture dimensions, and relative maxillary sinus volume were analyzed along with qualitative features of the piriform aperture rim. Results indicate that Neanderthals and other later Pleistocene Homo possessed NC's that align them with tropical modern humans. Thus comparison of Neanderthal nasal morphology with that of modern humans from cold climates may not be appropriate as differences in overall craniofacial architecture may constrain the narrowing of the piriform apertures in Neanderthals. They retain primitively long, low crania, large maxillary sinuses, and large piriform aperture area similar to mid-Pleistocene Homo specimens such as Petralona 1 and Kabwe 1. Adaptation to cold climate may have necessitated other adaptations such as bony medial projections at the piriform aperture rim and, potentially, midfacial prognathism. Nasal complex components of the upper respiratory tract remain a critical but poorly understood area that may yet offer novel insight into one of the greatest continuing controversies in paleoanthropology.

Evaluation of a new method of fossil retrodeformation by algorithmic symmetrization: crania of papionins (Primates, Cercopithecidae) as a test case.

Diagenetic distortion can be a major obstacle to collecting quantitative shape data on paleontological specimens, especially for three-dimensional geometric morphometric analysis. Here we utilize the recently-published algorithmic symmetrization method of fossil reconstruction and compare it to the more traditional reflection & averaging approach. In order to have an objective test of this method, five casts of a female cranium of Papio hamadryas kindae were manually deformed while the plaster hardened. These were subsequently "retrodeformed" using both algorithmic symmetrization and reflection & averaging and then compared to the original, undeformed specimen. We found that in all cases, algorithmic retrodeformation improved the shape of the deformed cranium and in four out of five cases, the algorithmically symmetrized crania were more similar in shape to the original crania than the reflected & averaged reconstructions. In three out of five cases, the difference between the algorithmically symmetrized crania and the original cranium could be contained within the magnitude of variation among individuals in a single subspecies of Papio. Instances of asymmetric distortion, such as breakage on one side, or bending in the axis of symmetry, were well handled, whereas symmetrical distortion remained uncorrected. This technique was further tested on a naturally deformed and fossilized cranium of Paradolichopithecus arvernensis. Results, based on a principal components analysis and Procrustes distances, showed that the algorithmically symmetrized Paradolichopithecus cranium was more similar to other, less-deformed crania from the same species than was the original. These results illustrate the efficacy of this method of retrodeformation by algorithmic symmetrization for the correction of asymmetrical distortion in fossils. Symmetrical distortion remains a problem for all currently developed methods of retrodeformation.

Continuity of mammalian fauna over the last 200,000 y in the Indian subcontinent.

Mammalian extinction worldwide during the Late Pleistocene has been a major focus for Quaternary biochronology and paleoecology. These extinctions have been variably attributed to the impacts of climate change and human interference. However, until relatively recently, research has been largely restricted to the Americas, Europe, and Australasia. We present the oldest Middle-Late Pleistocene stratified and numerically dated faunal succession for the Indian subcontinent from the Billasurgam cave complex. Our data demonstrate continuity of 20 of 21 identified mammalian taxa from at least 100,000 y ago to the present, and in some cases up to 200,000 y ago. Comparison of this fossil record to contemporary faunal ranges indicates some geographical redistribution of mammalian taxa within India. We suggest that, although local extirpations occurred, the majority of taxa survived or adapted to substantial ecological pressures in fragmented habitats. Comparison of the Indian record with faunal records from Southeast and Southwest Asia demonstrates the importance of interconnected mosaic habitats to long-term faunal persistence across the Asian tropics. The data presented here have implications for mammalian conservation in India today, where increasing ecological circumscription may leave certain taxa increasingly endangered in the most densely populated region of the world.

First joint record of Mesopithecus and cf. Macaca in the Miocene of Europe.

Cercopithecid fossil remains from the post-evaporitic Messinian (5.40-5.33 Ma, MN13, latest Turolian, latest Miocene) locality of Moncucco Torinese (Tertiary Piedmont Basin, NW Italy) are described. A talus is assigned to the fossil colobine Mesopithecus pentelicus, while a proximal fragment of ulna and a male lower canine are attributed to cf. Me. pentelicus. An isolated I(2) and M3 are assigned to the papionin cf. Macaca sp., and two cercopithecid phalanges are left unassigned even to the subfamily level. The record of Mesopithecus at Moncucco Torinese agrees well with the previously-known range of this species in Italy and elsewhere in Europe, whereas that of cf. Macaca constitutes only the second occurrence of macaques in the Miocene of Eurasia. Although the co-occurrence of these two genera in a single locality had been previously reported in the Pliocene, this is the first instance in which macaques are associated with the Late Miocene M. pentelicus instead of Mesopithecus monspessulanus. The record of cf. Macaca and Mesopithecus-and especially the latter's talar morphology, similar to that of extant arboreal colobines-fits well with paleoenvironmental reconstructions of Moncucco Torinese based on the associated fauna, which indicate a humid and densely-forested environment, probably with more open and drier habitats nearby. From a paleobiogeographic viewpoint, the record of Macaca at Moncucco Torinese, together with the previously reported occurrence at Almenara-Casablanca M (Spain), supports the contention that macaques dispersed from Africa into Europe during the latest Miocene (ca. 5.9-5.3 Ma) at the same time as the sea level drop associated with the Messinian Salinity Crisis.

Macrovertebrate paleontology and the Pliocene habitat of Ardipithecus ramidus.

A diverse assemblage of large mammals is spatially and stratigraphically associated with Ardipithecus ramidus at Aramis. The most common species are tragelaphine antelope and colobine monkeys. Analyses of their postcranial remains situate them in a closed habitat. Assessment of dental mesowear, microwear, and stable isotopes from these and a wider range of abundant associated larger mammals indicates that the local habitat at Aramis was predominantly woodland. The Ar. ramidus enamel isotope values indicate a minimal C4 vegetation component in its diet (plants using the C4 photosynthetic pathway), which is consistent with predominantly forest/woodland feeding. Although the Early Pliocene Afar included a range of environments, and the local environment at Aramis and its vicinity ranged from forests to wooded grasslands, the integration of available physical and biological evidence establishes Ar. ramidus as a denizen of the closed habitats along this continuum.