Fossil Apes Research Articles

Sexual dimorphism of body size in an African fossil ape, Nacholapithecus kerioi

Sexual size dimorphism in the African fossil ape Proconsul nyanzae (18 million years ago, 18 Ma) has been previously documented. However, additional evidence for sexual dimorphism in Miocene hominoids can provide great insight into the history of extant hominoid mating systems. The present study focused on body mass (BM) sexual dimorphism in Nacholapithecus kerioi from the Middle Miocene (16–15 Ma) in Africa. Bootstrap analysis revealed that P. nyanzae BM sexual dimorphism was lower than that in Pan troglodytes, which exhibits moderate sexual dimorphism, as reported previously. The same simulation revealed that BM sexual dimorphism of N. kerioi was comparable with that in Gorilla spp.; i.e., the males were approximately twice as large as the females. High sexual dimorphism in extant apes is usually indicative of a polygynous social structure (gorilla) or solitary/fission-fusion social system (orangutan). However, because of the high proportion of adult males in this fossil assemblage, the magnitude of dimorphism inferred here cannot be associated with a gorilla-like polygynous or oranguran-like solitary/fission-fusion social structure, and may reflect either taphonomic bias, or some other social structure. Extant hominoids have a long evolutionary history owing to their deep branching, comprising only a few existing members of the original highly successful group. Therefore, it is not surprising that the mating systems of extant hominoids fail to provide fossil apes with a perfect “model”. The mating systems of extinct hominoids may have been more diverse than those of extant apes.

Evolution and function of the hominin forefoot

The primate foot functions as a grasping organ. As such, its bones, soft tissues, and joints evolved to maximize power and stability in a variety of grasping configurations. Humans are the obvious exception to this primate pattern, with feet that evolved to support the unique biomechanical demands of bipedal locomotion. Of key functional importance to bipedalism is the morphology of the joints at the forefoot, known as the metatarsophalangeal joints (MTPJs), but a comprehensive analysis of hominin MTPJ morphology is currently lacking. Here we present the results of a multivariate shape and Bayesian phylogenetic comparative analyses of metatarsals (MTs) from a broad selection of anthropoid primates (including fossil apes and stem catarrhines) and most of the early hominin pedal fossil record, including the oldest hominin for which good pedal remains exist, Ardipithecus ramidus Results corroborate the importance of specific bony morphologies such as dorsal MT head expansion and "doming" to the evolution of terrestrial bipedalism in hominins. Further, our evolutionary models reveal that the MT1 of Ar. ramidus shifts away from the reconstructed optimum of our last common ancestor with apes, but not necessarily in the direction of modern humans. However, the lateral rays of Ar. ramidus are transformed in a more human-like direction, suggesting that they were the digits first recruited by hominins into the primary role of terrestrial propulsion. This pattern of evolutionary change is seen consistently throughout the evolution of the foot, highlighting the mosaic nature of pedal evolution and the emergence of a derived, modern hallux relatively late in human evolution.

Can Pallars i Llobateres: A new hominoid-bearing locality from the late Miocene of the Vallès-Penedès Basin (NE Iberian Peninsula)

In the Iberian Peninsula, Miocene apes (Hominoidea) are generally rare and mostly restricted to the Vallès-Penedès Basin. Here we report a new hominoid maxillary fragment with M2 from this basin. It was surface-collected in March 2017 from the site of Can Pallars i Llobateres (CPL, Sant Quirze del Vallès), where fossil apes had not been previously recorded. The locality of provenance (CPL-M), which has delivered no further fossil remains, is located very close (ca. 50 m) to previously known CPL outcrops, and not very far (ca. 500 m in NW direction) from the classical hominoid-bearing locality of Can Poncic 1. Here we describe the new fossil and, based on the size and proportions of the M2, justify its taxonomic attribution to Hispanopithecus cf. laietanus, a species previously recorded from several Vallesian sites of the Vallès-Penedès Basin. Based on the associated mammalian fauna from CPL, we also provide a biochronological dating and a paleoenvironmental reconstruction for the site. The associated fauna enables an unambiguous correlation to the Cricetulodon hartenbergeri – Progonomys hispanicus interval local subzone, with an estimated age of 9.98–9.73 Ma (late Vallesian, MN10). Therefore, CPL-M is roughly coeval with the Hispanopithecus laietanus-bearing localities of Can Llobateres 1 and Can Feu 1, and minimally older than those of La Tarumba 1 and Can Llobateres 2. In contrast, CPL-M is younger than the early Vallesian (MN9) localities of Can Poncic 1 (the type locality of Hispanopithecus crusafonti) as well as Polinyà 2 (Gabarró) and Estació Depuradora d’Aigües Residuals–Riu Ripoll 13, where Hispanopithecus sp. is recorded. The associated fauna from CPL indicates a densely forested and humid paleoenvironment with nearby freshwater. This supports the view that Hispanopithecus might have been restricted to dense wetland forests soon before its extinction during the late Vallesian, due to progressive climatic deterioration. Coupled with the existence of other fossiliferous outcrops in the area, this find is most promising for the prospect of discovering additional fossil hominoid remains in the future.

New infant cranium from the African Miocene sheds light on ape evolution.

The evolutionary history of extant hominoids (humans and apes) remains poorly understood. The African fossil record during the crucial time period, the Miocene epoch, largely comprises isolated jaws and teeth, and little is known about ape cranial evolution. Here we report on the, to our knowledge, most complete fossil ape cranium yet described, recovered from the 13 million-year-old Middle Miocene site of Napudet, Kenya. The infant specimen, KNM-NP 59050, is assigned to a new species of Nyanzapithecus on the basis of its unerupted permanent teeth, visualized by synchrotron imaging. Its ear canal has a fully ossified tubular ectotympanic, a derived feature linking the species with crown catarrhines. Although it resembles some hylobatids in aspects of its morphology and dental development, it possesses no definitive hylobatid synapomorphies. The combined evidence suggests that nyanzapithecines were stem hominoids close to the origin of extant apes, and that hylobatid-like facial features evolved multiple times during catarrhine evolution.

An Enigmatic Hypoplastic Defect of the Maxillary Lateral Incisor in Recent and Fossil Orangutans from Sumatra (Pongo abelii) and Borneo (Pongo pygmaeus)

Developmental dental pathologies provide insight into health of primates during ontogeny, and are particularly useful for elucidating the environment in which extant and extinct primates matured. Our aim is to evaluate whether the prevalence of an unusual dental defect on the mesiolabial enamel of the upper lateral incisor, thought to reflect dental crowding during maturation, is lesser in female orangutans, with their smaller teeth, than in males; and in Sumatran orangutans, from more optimal developmental habitats, than in those from Borneo. Our sample includes 49 Pongo pygmaeus (87 teeth), 21 P. abelii (38 teeth), Late Pleistocene paleo-orangutans from Sumatra and Vietnam (67 teeth), Late Miocene catarrhines Lufengpithecus lufengensis (2 teeth), and Anapithecus hernyaki (7 teeth). Methods include micro-CT scans, radiography, and dental metrics of anterior teeth. We observed fenestration between incisor crypts and marked crowding of unerupted crowns, which could allow tooth-to-tooth contact. Tooth size does not differ significantly in animals with or without the defect, implicating undergrowth of the jaw as the proximate cause of dental crowding and defect presence. Male orangutans from both islands show more defects than do females. The defect is significantly more common in Bornean orangutans (71 %) compared to Sumatran (29 %). Prevalence among fossil forms falls between these extremes, except that all five individual Anapithecus show one or both incisors with the defect. We conclude that maxillary lateral incisor defect is a common developmental pathology of apes that is minimized in optimal habitats and that such evidence can be used to infer habitat quality in extant and fossil apes.

Rodent-based age appraisal of the Lower Siwalik Subgroup of Kalaunta, Ramnagar, Jammu, India

Parmar, V., Magotra, R., Norboo, R. & Prasad, G.V.R., July 2016. Rodent-based age appraisal of the Lower Siwalik Subgroup of Kalaunta, Ramnagar, Jammu, India. Alcheringa 41, xx-xx. ISSN 0311-5518.Rocks of the Lower Siwalik Subgroup exposed around Ramnagar town in Jammu, India, have been known for more than 90 years to yield Chinji-equivalent (14.2–11.2 Ma) hominoid fossils. In 1997, the fossil ape Sivapithecus reported near Kalaunta village in the vicinity of Ramnagar was argued to be about 18 Ma old by its discoverers. This had implications for hominoid evolutionary studies, as molecular clock calibrations are commonly based on Sivapithecus first appearance datum (FAD). In a paper published in 2010, the identification of this hominoid tooth was questioned and reassigned to a suid. Recently, based upon the discovery of an indeterminate fossil bovid from the supposedly hominoid-yielding site near Kalaunta, an age estimate between ca 13.9 and 10.8 Ma was provided. As rodent biochronology has proven to be useful in age assignment of upper Cenozoic terrestrial sequences, the age of the fossil-bearing Lower Siwalik Subgroup of Kalaunta is re-assessed based upon newly recovered cricetid taxa. The cricetid rodents from this site comprise Punjabemys downsi and P. mikros. These two species are known to exist in the well-dated Potwar Siwalik Group succession between 14.3 and 12.6 Ma and between 16.3 and 13.0 Ma, respectively. Based on the overlapping temporal ranges of the cricetid taxa and an indeterminate Bovidae (ca 13.9–10.8 Ma) reported previously from this area, an age of 13.9–13.0 Ma is inferred for rocks occurring in the vicinity of Kalaunta. The new finds refute earlier claims of rocks in the area extending back to ca 18 Ma or as young as 10.8 Ma.Varun Parmar [varunparmarvp@gmail.com], Rahul Magotra [rahulmagotra01@gmail.com] and Rigzin Norboo [norboo04@gmail.com], Post Graduate Department of Geology, University of Jammu, Jammu, 180 006, India; Guntupalli Veera Raghavendra Prasad [guntupalli.vrprasad@gmail.com], Department of Geology, Centre for Advanced Studies, University of Delhi, Delhi, 110 007, India.

Stable isotopes show resource partitioning among the early Late Miocene herbivore community at Rudabánya II: Paleoenvironmental implications for the hominoid, Rudapithecus hungaricus

Examining how species use and partition resources within an environment can lead to a better understanding of community assembly and diversity. The rich early Late Miocene (early Vallesian) deposits at Rudabánya II (R. II) in northern central Hungary preserve an abundance of forest dwelling taxa, including the hominoid Rudapithecus hungaricus. Here we use the carbon and oxygen stable isotope compositions of tooth enamel carbonate from 10 genera of medium to large-bodied mammals to evaluate resource use and partitioning among the herbivore community, and to reconstruct the paleoenvironment of Rudapithecus. The range of stable carbon and oxygen isotope values (δ13CE and δ18OE) displayed by the R. II fauna indicates a variable forest environment, which included both open and closed canopy habitats. The relatively low δ13CE and δ18OE values found in all sampled taxa are consistent with high levels of precipitation and humidity. Significant differences in stable isotope values were observed among the sampled fauna, supporting the interpretation of resource specialization and partitioning. Higher δ13CE values found in Aceratherium incisivum (Rhinocerotidae), Lucentia aff. pierensis (Cervidae), Hippotherium intrans (Equidae), Tetralophodon longirostris (Gomphotheriidae), Propotamochoerus palaeochoerus and Parachleuastochoerus kretzoii (Suidae) suggest foraging in more open canopy habitats, while lower δ13CE values found in Miotragocerus sp. (Bovidae), Dorcatherium naui (Tragulidae), and Micromeryx flourensianus (Moschidae) imply a preference for more densely canopied habitats. Several of the sampled taxa yielded relatively higher δ18OE and δ13CE values indicative of fruit consumption, including the small ruminants, cervid, and bovid. The analyzed isotope values reflect a moderate degree of dietary niche overlap between taxa. An abundance of plant resources likely allowed for the coexistence of this diverse community of predominantly browsing herbivores. Within the gradient of more open to closed canopy forest, it is likely that Rudapithecus occupied dense closed canopy habitats where access to fruit was relatively continuous. The progressive fragmentation and replacement of humid forests by more open and seasonal woodlands during the late Vallesian would have had a significant influence on the extinction of this fossil ape.

Dental development in living and fossil orangutans

Numerous studies have investigated molar development in extant and fossil hominoids, yet relatively little is known about orangutans, the only great ape with an extensive fossil record. This study characterizes aspects of dental development, including cuspal enamel daily secretion rate, long-period line periodicities, cusp-specific molar crown formation times and extension rates, and initiation and completion ages in living and fossil orangutan postcanine teeth. Daily secretion rate and periodicities in living orangutans are similar to previous reports, while crown formation times often exceed published values, although direct comparisons are limited. One wild Bornean individual died at 4.5 years of age with fully erupted first molars (M1s), while a captive individual and a wild Sumatran individual likely erupted their M1s around five or six years of age. These data underscore the need for additional samples of orangutans of known sex, species, and developmental environment to explore potential sources of variation in molar emergence and their relationship to life history variables. Fossil orangutans possess larger crowns than living orangutans, show similarities in periodicities, and have faster daily secretion rate, longer crown formation times, and slower extension rates. Molar crown formation times exceed reported values for other fossil apes, including Gigantopithecus blacki. When compared to African apes, both living and fossil orangutans show greater cuspal enamel thickness values and periodicities, resulting in longer crown formation times and slower extension rates. Several of these variables are similar to modern humans, representing examples of convergent evolution. Molar crown formation does not appear to be equivalent among extant great apes or consistent within living and fossil members of Pongo or Homo.

Flexibility of diet and habitat in Pleistocene South Asian mammals: Implications for the fate of the giant fossil ape Gigantopithecus

Determining the diet of fossil apes is essential to understand primate evolution. The giant form from Southeast Asia, Gigantopithecus blacki, may have been up to 270 kg and survived until about 100,000 years ago. It is known only from isolated teeth and a few lower jaws with reduced front teeth and enlarged molars and premolars. A large spectrum of diets has been suggested for Gigantopithecus, ranging from carnivorous or grass-feeding in open savannah to a vegetarian diet dominated by fruits or bamboo. To determine its habitat and to understand why it became extinct, we tried to evaluate its dietary niche. The carbon stable isotopic composition of tooth enamel of this taxon compared to coeval and extant mammals from Southeastern Asia show that Gigantopithecus was a forest-dweller with a generalist vegetarian diet and was not specialized on bamboos. In southern China, Gigantopithecus lived in a forested environment, as did the coeval fauna, while in Thailand, it occupied only the forested part of a mosaic landscape including significant parts of open savannah. The carbon isotopic compositions of Gigantopithecus were different from those of omnivorous and carnivorous taxa, but very similar to those of orang-utans and unlike those of the bamboo-specialist giant panda. Therefore, even when open savannah environments were present in the landscape, Gigantopithecus foraging was limited to forested habitats. The very large size of Gigantopithecus, combined with a relatively restricted dietary niche, may explain its demise during the drastic forest reduction that characterized the glacial periods in South East Asia.

The Anthropoid Crista Trochanterica and the Hip Joint Capsule.

The tubercle on the posterior aspect of the femoral neck (the crista trochanterica) has been repeatedly remarked upon because of its presence in early fossil apes, yet the function of this tubercle has eluded researchers. The prevailing explanation for the tubercle is that it relates to a strong ischiofemoral ligament, although none of the hypotheses for this bony projection have been systematically evaluated. This study surveyed 41 extant anthropoid species (n = 267 individuals) for the presence of a crista trochanterica. The soft tissue structures of the hip joint were then dissected and described for a sample of anthropoid cadavers (n = 14) in order to evaluate different hypotheses related to function of this tubercle. This study confirmed that the crista trochanterica is found in most cercopithecoids and platyrrhines, and is not present in great apes. The tubercle is rarely present in hylobatids, contrary to prior reports. The ischiofemoral ligament is not usually well-developed in anthropoids and does not fully explain the crista trochanterica morphology, although all cadavers displayed a well-developed zona orbicularis running along the posterior aspect of the joint capsule. The hip joint capsule itself inserted along the crista trochanterica in some individuals, typically those with an elongate crista trochanterica, but was highly variable in regards to the position of the tubercle. The hypotheses for the crista trochanterica are considered within the context of these findings, although the exact function of the tubercle remains unresolved.

Enamel thickness and enamel growth in Oreopithecus: Combining microtomographic and histological evidence

Oreopithecus bambolii, a large-bodied fossil ape, lived in the Tusco-Sardinian archipelago during the Late Miocene, until ca. 6.7Ma. Its dentition, an apparent blend of hominoid and cercopithecoid-like features, has been a matter of discussion since its first description, in 1872. While the height and sharpness of its molar cusps recall some Cercopithecidae, Oreopithecus is currently considered by many as more likely related to dryopithecines. Here, we use microtomographic-based quantitative imaging and histological evidence to link outer and inner tooth structural morphology with enamel development in Oreopithecus permanent teeth. The material consists of 14 teeth/crowns from the sites of Baccinello and Casteani, in Tuscany, and Fiume Santo, in Sardinia. In particular, we add to the record of 2–3D of molar enamel thickness topographic variation and enamel-dentine junction morphology, and using high-resolution replicas of the outer crown and ground sections, comparatively assess molar growth trajectory (crown formation times and enamel extension rates). Our results shed new light on dental development of this “enigmatic anthropoid” and provide additional evidence concerning the still debated question of its evolutionary history.

The interpretive power of infraorbital foramen area in making dietary inferences in extant apes.

The infraorbital foramen (IOF) is located below the orbit and transmits the sensory infraorbital nerve (ION) to mechanoreceptors located throughout the maxillary region. The size of the IOF correlates with the size of the ION; thus, the IOF appears to indicate relative touch sensitivity of maxillary region. In primates, IOF size correlates well with diet. Frugivores have relatively larger IOFs than folivores or insectivores because fruit handling/processing requires increased touch sensitivity. However, it is unknown if the IOF can be used to detect subtle dietary differences among closely related hominoid species. Hominoids are traditionally grouped into broad dietary categories, despite the fact that hominoid diets are remarkably diverse. This study examines whether relative IOF size is capable of differentiating among the dietary preferences of closely related species with overlapping, yet divergent diets. We measured IOF area in Hylobates lar, Symphalangus syndactulus, Pongo pygmaeus spp., Pan troglodytes, Gorilla gorilla, Gorilla beringei graueri, and Gorilla beringei beringei. We classified each species as a dedicated folivore, mixed folivore/frugivore, soft object frugivore, or hard object frugivore. The IOF is documented to be larger in more frugivorous species and smaller in more folivorous taxa. Interestingly, G.b. beringei, had the largest relative IOF of any gorilla, despite being a dedicated folivore. G.b. beringei does have unique food processing behavior that relies heavily on maxillary mechanoreception, thus this finding is not entirely unsupported behaviorally. The results of this study provide evidence that the IOF is an informative feature in interpretations of fossil apes.

Remnants of an ancient forest provide ecological context for Early Miocene fossil apes

The lineage of apes and humans (Hominoidea) evolved and radiated across Afro-Arabia in the early Neogene during a time of global climatic changes and ongoing tectonic processes that formed the East African Rift. These changes probably created highly variable environments and introduced selective pressures influencing the diversification of early apes. However, interpreting the connection between environmental dynamics and adaptive evolution is hampered by difficulties in locating taxa within specific ecological contexts: time-averaged or reworked deposits may not faithfully represent individual palaeohabitats. Here we present multiproxy evidence from Early Miocene deposits on Rusinga Island, Kenya, which directly ties the early ape Proconsul to a widespread, dense, multistoried, closed-canopy tropical seasonal forest set in a warm and relatively wet, local climate. These results underscore the importance of forested environments in the evolution of early apes.

Chimpanzee fauna isotopes provide new interpretations of fossil ape and hominin ecologies

Carbon and oxygen stable isotopes within modern and fossil tooth enamel record the aspects of an animal's diet and habitat use. This investigation reports the first isotopic analyses of enamel from a large chimpanzee community and associated fauna, thus providing a means of comparing fossil ape and early hominin palaeoecologies with those of a modern ape. Within Kibale National Park forest, oxygen isotopes differentiate primate niches, allowing for the first isotopic reconstructions of degree of frugivory versus folivory as well as use of arboreal versus terrestrial resources. In a comparison of modern and fossil community isotopic profiles, results indicate that Sivapithecus, a Miocene ape from Pakistan, fed in the forest canopy, as do chimpanzees, but inhabited a forest with less continuous canopy or fed more on leaves. Ardipithecus, an early hominin from Ethiopia, fed both arboreally and terrestrially in a more open habitat than inhabited by chimpanzees.

The femur of Orrorin tugenensis exhibits morphometric affinities with both Miocene apes and later hominins

Orrorin tugenensis (Kenya, ca. 6 Ma) is one of the earliest putative hominins. Its proximal femur, BAR 1002'00, was originally described as being very human-like, although later multivariate analyses showed an australopith pattern. However, some of its traits (for example, laterally protruding greater trochanter, medially oriented lesser trochanter and presence of third trochanter) are also present in earlier Miocene apes. Here, we use geometric morphometrics to reassess the morphological affinities of BAR 1002'00 within a large sample of anthropoids (including fossil apes and hominins) and reconstruct hominoid proximal femur evolution using squared-change parsimony. Our results indicate that both hominin and modern great ape femora evolved in different directions from a primitive morphology represented by some fossil apes. Orrorin appears intermediate between Miocene apes and australopiths in shape space. This evidence is consistent with femoral shape similarities in extant great apes being derived and homoplastic and has profound implications for understanding the origins of human bipedalism.

Juvenile hominoid cranium from the terminal Miocene of Yunnan, China

Fossil apes are known from several late Miocene localities in Yunnan Province, southwestern China, principally from Shihuiba (Lufeng) and the Yuanmou Basin, and represent three species of Lufengpithecus. They mostly comprise large samples of isolated teeth, but there are also several partial or complete adult crania from Shihuiba and a single juvenile cranium from Yuanmou. Here we describe a new, relatively complete and largely undistorted juvenile cranium from the terminal Miocene locality of Shuitangba, also in Yunnan. It is only the second ape juvenile cranium recovered from the Miocene of Eurasia and it is provisionally assigned to the species present at Shihuiba, Lufengpithecus lufengensis. Lufengpithecus has most often been linked to the extant orangutan, Pongo pygmaeus, but recent studies of the crania from Shihuiba and Yuanmou have demonstrated that this is unlikely. The new cranium reinforces the view that Lufengpithecus represents a distinct, late surviving lineage of large apes in the late Miocene of East Asia that does not appear to be closely affiliated with any extant ape lineage. It substantially increases knowledge of cranial morphology in Lufengpithecus and demonstrates that species of this genus represent a morphologically diverse radiation of apes, which is consistent with the dynamic tectonic and biotic milieu of southwestern China in the late Miocene.

Fossil apes from the vallès‐penedès basin

Currently restricted to Southeast Asia and Africa, extant hominoids are the remnants of a group that was much more diverse during the Miocene. Apes initially diversified in Africa during the early Miocene, but by the middle Miocene they extended their geographical range into Eurasia, where they experienced an impressive evolutionary radiation. Understanding the role of Eurasian hominoids in the origin and evolution of the great-ape-and-human clade (Hominidae) is partly hampered by phylogenetic uncertainties, the scarcity and incompleteness of fossil remains, the current restricted diversity of the group, and pervasive homoplasy. Nevertheless, scientific knowledge of the Eurasian hominoid radiation has significantly improved during the last decade. In the case of Western Europe, this has been due to the discovery of new remains from the Vallès-Penedès Basin (Catalonia, Spain). Here, I review the fossil record of Vallès-Penedès apes and consider its implications. Although significant disagreements persist among scholars, some important lessons can be learned regarding the evolutionary history of the closest living relatives of humans.

Brief communication: Paleobiological inferences on the locomotor repertoire of extinct hominoids based on femoral neck cortical thickness: The fossil great ape hispanopithecus laietanus as a test‐case study

The relationship between femoral neck superior and inferior cortical thickness in primates is related to locomotor behavior. This relationship has been employed to infer bipedalism in fossil hominins, although bipeds share the same pattern of generalized quadrupeds, where the superior cortex is thinner than the inferior one. In contrast, knuckle-walkers and specialized suspensory taxa display a more homogeneous distribution of cortical bone. These different patterns, probably related to the range of movement at the hip joint and concomitant differences in the load stresses at the femoral neck, are very promising for making locomotor inferences in extinct primates. To evaluate the utility of this feature in the fossil record, we relied on computed tomography applied to the femur of the Late Miocene hominoid Hispanopithecus laietanus as a test-case study. Both an orthograde body plan and orang-like suspensory adaptations had been previously documented for this taxon on different anatomical grounds, leading to the hypothesis that this fossil ape should display a modern ape-like distribution of femoral neck cortical thickness. This is confirmed by the results of this study, leading to the conclusion that Hispanopithecus represents the oldest evidence of a homogeneous cortical bone distribution in the hominoid fossil record. Our results therefore strengthen the utility of femoral neck cortical thickness for making paleobiological inferences on the locomotor repertoire of fossil primates. This feature would be particularly useful for assessing the degree of orthograde arboreal locomotor behaviors vs. terrestrial bipedalism in putative early hominins.

Juvenile hominoid cranium from the late Miocene of southern China and hominoid diversity in Asia.

The fossil ape Lufengpithecus is known from a number of late Miocene sites in Yunnan Province in southern China. Along with other fossil apes from South and Southeast Asia, it is widely considered to be a relative of the extant orangutan, Pongo pygmaeus. It is best represented at the type site of Shihuiba (Lufeng) by several partial to nearly complete but badly crushed adult crania. There is, however, an additional, minimally distorted cranium of a young juvenile from a nearly contemporaneous site in the Yuanmou Basin, which affords the opportunity to better assess the relationships between Lufengpithecus and Pongo. Comparison with similarly aged juvenile skulls of extant great apes reveals no features suggesting clear affinities to orangutans, and instead reveals a morphological pattern largely consistent with a stem member of the hominid (great ape and human) clade. The existence at this time of other hominids in South Asia (Sivapithecus) and Southeast Asia (Khoratpithecus) with clear craniofacial affinities to Pongo suggests both more diversity among Asian Late Miocene apes and more complex patterns of dispersal than previously supposed. Major differences in the associated mammal faunas from the southern China sites and those from South and Southeast Asia are consistent with these findings and suggest more than one dispersal route of apes into East Asia earlier in the Miocene.

Basel–Tuscany, a long-lasting link

A significant contribution of Burkart Engesser to fieldsurveys and palaeontological studies is undoubtedly on theLate Miocene faunas from Maremma in southern Tuscany,especially the celebrated Baccinello basin in the Grossetodistrict. This is not just a coincidence, but is the continu-ation of a long tradition.The interest of successive Palaeontologists of theNaturhistorisches Museum Basel (NMB) in Tuscan fossilsand fossiliferous localities has a long history that datesback to the second half of the nineteenth century. Thisstarted with Ludwig Ru¨timeyer (1825–1895) who was theprofessor of Zoology and Comparative Anatomy at theUniversity of Basel in 1855. Ru¨timeyer was mainly inter-ested in the natural history of Tertiary mammal species,and a number of specimens from Italy (as well as fromother countries in Europe, especially France) were acquiredby the NMB during his period of activity.The interest in the Tuscan mammal fossil record becameparticularly strong thanks to the activity of CharlesImmanuel Forsyth Major (1843–1923), a physician ofScottish origin who grew up in Switzerland. He graduatedin Medicine in Basel in 1868 and started his professionalpractice in Florence (Italy) where he stayed for about adecade. As many nineteenth century medical doctors,however, he was fascinated by natural history and devotedmuch of his spare time to the study of fossil mammals. Hisinterest in extinct vertebrates exceeded his dedication tomedicine, so that he finally decided to cease practising inthe mid 1880s. Forsyth Major was a correspondent ofCharles Darwin (Cioppi & Dominici, 2010), and his nameappears three times in the second edition of The Descent ofMan (a much improved edition, published in 1874) aboutsexual dimorphisms in fossil pigs tusks, about the occur-rence of fossil apes in Europe, and about a bovid skull‘‘wholly without horns’’ from Upper Valdarno, believed tobe that of a ‘‘Bos etruscus’’ female. The latter is an issuethat re-addresses us to the story of the Basel-Florenceexchanges. About this specimen (housed in the collectionof the Florence Museum), Forsyth Major (1874, 1890) wasin disagreement with ‘‘the leading authority in the field ofTertiary Ruminants’’, i.e. Ru¨timeyer. The eminent palae-ontologist from Basel (Ru¨timeyer, 1878) described thisspecimen as type of a new species (Leptobos strozzii), lateron formally synonymzed to L. etruscus by Forsyth Major(1890). Forsyth Major’s main interests were especiallyPrimates and, more generally speaking, Plio-Pleistocenemammals (e.g. among others, Forsyth Major, 1872,1875–1877, 1890). His entire scientific production clearlyshows how deep his attention was for Tuscan vertebratefossils, and whilst he was active in Florence, he system-atically searched for new material, mainly in Tuscany butalso in other Italian regions (Sardinia, Calabria, Sicily),bringing hundreds of specimens to the Florence Museum.Forsyth Major had intensive relationships with colleaguesand institutions across Europe and in Basel too. Samplescollected during his Italian field surveys are now housed inseveral museums, amongst others in the Natural History,London, in the Colle`ge Gaillard in Lausanne (Switzerland),and in the Naturhistorisches Museum Basel.Other Tuscan material (namely from Upper Valdarno)kept in Basel from the Plio-Pleistocene of Italy was boughtby another eminent Basel palaeontologist, Hans GeorgStehlin (1870–1941). He was the president of the board ofthe Naturhistorisches Museum from 1920 to 1940 and astudent of Ludwig Ru¨timeyer at the University of Basel.