Tao Qi

The oldest known anthropoid postcranial fossils and the early evolution of higher primates.

The middle Eocene primate family Eosimiidae, which is known from sites in central and eastern China and Myanmar, is central to efforts to reconstruct the origin and early evolution of anthropoid or ‘higher’ primates (monkeys, apes and humans). Previous knowledge of eosimiid anatomy has been restricted to the dentition and an isolated petrosal bone, and this limited anatomical information has led to conflicting interpretations of early anthropoid phylogeny. Here we describe foot bones of Eosimias from the same middle Eocene sites in China that yield abundant dental remains of this primate. Tarsals of Eosimias show derived anatomical traits that are otherwise restricted to living and fossil anthropoids. These new fossils substantiate the anthropoid status of Eosimias and clarify the phylogenetic position of anthropoids with respect to other major primate clades. Early anthropoids possessed a mosaic of primitive and derived traits in their postcranial skeletons, reflecting their derivation from haplorhine ancestors that retained many prosimian-like features.

New chiropterans from the middle Eocene of Shanghuang (Jiangsu Province, Coastal China): new insight into the dawn horseshoe bats (Rhinolophidae) in Asia

Until recently, the fossil record of Paleogene bats in Asia primarily included extinct families (i.e. ‘Eochiroptera’) from the early Eocene of Vastan in India and from the middle‐late Eocene of the Liguanqiao and Yuanqu basins in central China. Here, we describe a new fauna of Chiroptera from the middle Eocene Shanghuang fissure fillings of China. The fauna includes abundant material referred to a new rhinolophid (Protorhinolophus shanghuangensis gen. and sp. n.), one specimen of a possible rhinopomatid and several indeterminate rhinolophoids. This new bat assemblage constitutes the earliest record of extant families of microbats in Asia. Because it lacks representatives of ‘Eochiroptera’, this Shanghuang bat fauna indicates significant turnover in Asian bat communities. The dental pattern of P. shanghuangensis shows a mosaic of primitive and derived features (‘Eochiroptera’ vs Rhinolophidae dental characteristics), suggesting that this taxon occupies a basal position among the Rhinolophidae. Rhinolophids were already well diversified at the end of the late Eocene in Europe. Interestingly, many dental characteristics of Protorhinolophus are also found in a primitive rhinolophoid taxon, Vaylatsia, from the middle Eocene to late Oligocene of Europe, supporting a close relationship between these taxa. These affinities testify to the widespread Eurasian distribution of rhinolophoids during the Eocene and are consistent with a westward dispersal of the group from eastern Asia to Europe owing to the greater antiquity of Protorhinolophus.

A Haplorhine First Metatarsal from the Middle Eocene of China

We are honored to celebrate the career and scholarship of Professor Elwyn L. Simons. His body of work covering the field of paleoprimatology is staggering in quantity and quality. Elwyn’s record of recovery, description, and analysis of the Fayum fossil primates from Egypt is undoubtedly his greatest contribution in a phenomenally long and productive career. We thank him for his insights, hard work, and patience, having trained most of us studying primate evolution. Our contribution concerns the description of a new fossil – something Elwyn has done so many times before. We describe a primate first metatarsal from the Eocene of Asia. A newly discovered first metatarsal from the middle Eocene ( 45 mya) Shanghuang fissures (fissure D) in southern Jiangsu Province, China, provides the first evidence for the anatomy of the grasping mechanism of the Shanghuang primates. Since the form of the grasping foot is a fundamental character complex that distinguishes primitive (‘‘prosimian’’) and more derived (crowngroup anthropoid) primates, this bone also allows us to assess the taxonomic status of Shanghuang primates and to consider the changing role of primate grasping through time and its relevance to higher primate evolution.

Middle-Eocene artiodactyls from Shanghuang (Jiangsu Province, Coastal China) and the diversity of basal dichobunoids in Asia.

A new assemblage of basal dichobunoid artiodactyls from the middle-Eocene Shanghuang fissure fillings includes the diacodexeid Jiangsudon shanghuangensis gen. and sp. nov., a new species of the lantianine dichobunoid Elaschitotherium, Elaschitotherium crepaturus sp. nov., and an indeterminate suoid which is presently the earliest record of this clade. Diacodexeids are also represented by two forms provisionally referred to cf. Diacodexis sp. and to an indeterminate Diacodexeidae, respectively. The occurrence of diacodexeids in Shanghuang contrasts with the early and earliest middle-Eocene chronological range of the family in Europe and North America and suggests that the stratigraphic range of the family in Asia extends up to the middle Eocene. This may reflect particular habitats in coastal China that may have been relatively stable during the early and middle Eocene, thus preserving forest-dwelling artiodactyls that became extinct in the other Holarctic regions. Compared to other supposedly coeval North American, European, and Asian faunas, the Shanghuang mammalian assemblage is most similar to early Uintan faunas of North America but is also remarkable in recording forms close to taxa that are characteristic of the Wasatchian and Bridgerian North American Land Mammal Ages. The Irdinmanhan age of the Shanghuang fauna is supported by the mammalian assemblage recovered from the fissure D, but an Arshantan age cannot be completely ruled out at this point. Although the Shanghuang assemblage is biased towards preservation of small components of the mammalian fauna, the Shanghuang fauna provide an important and unique window into the Eocene diversity and early evolution of cetartiodactyls in eastern Asia.

Primate Tibiae from the Middle Eocene Shanghuang Fissure-Fillings of Eastern China

Since this is a volume in celebration of the work of Frederick S. Szalay, we think it is entirely appropriate to open with an appreciation. We gratefully acknowledge Dr. Szalay’s innovative efforts to bring the study of mammalian postcranial remains to the forefront of evolutionary morphology, a development that has inspired all of our research. MD thanks Dr. Szalay for being a supportive mentor, for instilling a broad and deep understanding of evolutionary biology, for generously allowing a naive graduate student access to important fossil specimens, and for providing the most stimulating environment for research. DLG thanks Dr. Szalay for his many kindnesses 13. Primate Tibiae from the Middle Eocene Shanghuang Fissure-Fillings of Eastern China

Primate Humeral Remains from the Middle Eocene of China

Abstract Two distal humeral fragments are described from the middle Eocene Shanghuang fissures (southern Jiangsu Province, China). These specimens provide the first evidence of forelimb morphology among Shanghuang primates. One specimen belongs to an adapiform strepsirhine primate that is morphologically similar to European adapines, while the other pertains to a small haplorhine primate having numerous features in common with North American omomyids. Both fossils exhibit classic primate elbow adaptations that are functionally related to arboreality and climbing.

A NEW BUNOSELENODONT ARTIODACTYL FROM THE MIDDLE EOCENE OF CHINA AND THE EARLY RECORD OF SELENODONT ARTIODACTYLS IN ASIA

The vast continent of Asia is thought to have played a major role in the origin and early differentiation of several extant groups of ungulate mammals, including artiodactyls (e.g. Beard, 1998). According to Gentry and Hooker (1988), Selenodontia are a major division within Artiodactyla encompassing many extinct forms that are more closely related to extant ruminants and camels than to pigs and hippos (Bunodontia). Living ruminants are characterized by their highly derived digestive system, which is not preserved in fossils. Bony features that are closely correlated with this critical physiological innovation have yet to be identified. The incisiform lower canine and the loss of upper incisors are dental features that help to define extant ruminants, but these characters are rarely preserved in the fossil record. Moreover, Archaeomeryx from the middle Eocene of Mongolia, which is classically regarded as the earliest known ruminant, still retains its upper incisors (Matthew and Granger, 1925). In terms of osteology, the main apomorphic feature uniting all Ruminantia is the fusion of two tarsal bones (cuboid and navicular), although this feature may have evolved at least twice during in the evolutionary history of selenodont artiodactyls (Sudre and Blondel, 1995). Accordingly, it can be problematic to distinguish a “true ruminant” from the multitude of extinct proto-selenodont forms that radiated during the middle Eocene in the Northern Hemisphere. Moreover, the poor record of early Selenodontia in Asia greatly hampers our understanding of their origin and early evolution. Except for Archaeomeryx, which is known from several fairly complete skeletons from Mongolia (Matthew and Granger, 1925; Colbert, 1941; Webb and Taylor, 1980; Vislobokova, 1998, 2001), the early selenodonts of Asia are limited to fragmentary jaws and isolated teeth from the middle and late Eocene (Guo et al., 2000; Métais et al., 2001; Tsubamoto et al., 2003). Here, we describe a new genus and species that is characterized by a combination of primitive ‘dichobunoid’ dental features together with derived dental characters that are reminiscent of early ruminants. The fossils were collected by screen-washing the fossiliferous clays from the middle Eocene fissure-filling complex near the village of Shanghuang in southern Jiangsu Province, People’s Republic of China (Fig. 1). Five distinct fissure fillings (designated A through E) have been sampled from the Triassic Shangqinglong limestone at Shanghuang. Artiodactyl remains have been retrieved from all the fissures, but the taxon described here is known so far only from fissure-filling D, which has also yielded a lantianine dichobunid (Métais et al., 2004), brontotheriid perissodactyls (Qi and Beard, 1996, 1998), primates (Beard et al., 1994; MacPhee et al., 1995), rodents (Wang and Dawson, 1994; Dawson and Wang, 2001), and other mammals that are currently under study. According to Dawson & Wang (2001), fissure D is middle Eocene in age and probably correlates with the Irdinmanhan Asian Land Mammal Age (see Russell and Zhai, 1987).