Uniquely derived upper molar morphology of Eocene Amphipithecidae (Primates: Anthropoidea): Homology and phylogeny

The extinct Southeast Asian primate family Amphipithecidae is regularly cited in discussions of anthropoid origins, but its phylogenetic position remains controversial. In part, the lack of consensus regarding amphipithecid relationships can be attributed to uncertainty regarding the homology of upper molar structures in this group. Here, we describe a virtually pristine upper molar of Pondaungia cotteri from the late middle Eocene Pondaung Formation of Myanmar, which is the first example of a relatively unworn and well-preserved amphipithecid upper molar ever recovered. The distolingual upper molar cusp in this new specimen of Pondaungia appears to be a lingually displaced and enlarged metaconule, rather than a hypocone or pseudohypocone as previous workers have thought. Reassessment of the upper molar morphology of other amphipithecids and putative amphipithecids reveals a very similar pattern in Siamopithecus, Myanmarpithecus and Ganlea, all of which are interpreted as having upper molars showing many of the same derived features apparent in Pondaungia. In contrast, the upper molar morphology of Bugtipithecus diverges radically from that of undoubted amphipithecids, and the latter taxon is excluded from Amphipithecidae on this basis. Phylogenetic analyses of several character–taxon matrices culled from the recent literature and updated to reflect the new information on amphipithecid upper molar morphology yield similar results. Consensus tree topologies derived from these analyses support amphipithecid monophyly and stable relationships within Amphipithecidae. Amphipithecids appear to be stem members of the anthropoid clade.     

The paleobiology of Amphipithecidae, South Asian late Eocene primates

Analysis of the teeth, orbital, and gnathic regions of the skull, and fragmentary postcranial bones provides evidence for reconstructing a behavioral profile of Amphipithecidae: Pondaungia, Amphipithecus, Myanmarpithecus (late middle Eocene, Myanmar) and Siamopithecus (late Eocene, Thailand). At 5-8 kg, Pondaungia, Amphipithecus, and Siamopithecus are perhaps the largest known Eocene primates. The dental and mandibular anatomy suggest that large-bodied amphipithecids were hard-object feeders. The shape of the mandibular corpus and stiffened symphysis suggest an ability to resist large internal loads during chewing and to recruit significant amounts of muscle forces from both the chewing and non-chewing sides of the jaw so as to increase bite force during mastication. The large spatulate upper central incisor of Pondaungia and projecting robust canines of all the larger amphipithecids suggest that incisal food preparation was important. The molars of Siamopithecus, Amphipithecus, and Pondaungia have weak shearing crests. This, and the thick molar enamel found in Pondaungia, suggests a diet of seeds and other hard objects low in fiber. In contrast, Myanmarpithecus was smaller, about 1-2 kg; its cheek teeth suggest a frugivorous diet and do not imply seed eating. Postcranial bones (humerus, ulna, and calcaneus) of a single large amphipithecid individual from Myanmar suggest an arboreal quadrupedal locomotor style like that of howler monkeys or lorises. The humeral head is rounded, proximally oriented, and the tuberosities are low indicating an extremely mobile glenohumeral joint. The great thickness of the midshaft cortical bone of the humerus implies enhanced ability to resist bending and torsion, as seen among slow moving primate quadrupeds. The elbow joint exhibits articular features for enhanced stability in habitually flexed positions, features also commonly found in slow moving arboreal quadrupeds. The short distal load arm of the calcaneus is consistent with, but not exclusive to, slow, arboreal quadrupedalism, and suggests no reliance on habitual leaping.     

A new primate from the Eocene Pondaung Formation of Myanmar and the monophyly of Burmese amphipithecids

The family Amphipithecidae is one of the two fossil primate taxa from Asia that appear to be early members of the anthropoid clade. Ganlea megacanina, gen. et sp. nov., is a new amphipithecid from the late middle Eocene Pondaung Formation of central Myanmar. The holotype of Ganlea is distinctive in having a relatively enormous lower canine showing heavy apical wear, indicating an important functional role of the lower canine in food preparation and ingestion. A phylogenetic analysis of amphipithecid relationships suggests that Ganlea is the sister taxon of Myanmarpithecus, a relatively small-bodied taxon that has often, but not always, been included in Amphipithecidae. Pondaungia is the sister taxon of the Ganlea + Myanmarpithecus clade. All three Pondaung amphipithecid genera are monophyletic with respect to Siamopithecus, which is the most basal amphipithecid currently known. The inclusion of Myanmarpithecus in Amphipithecidae diminishes the likelihood that amphipithecids are specially related to adapiform primates. Extremely heavy apical wear has been documented on the lower canines of all three genera of Burmese amphipithecids. This distinctive wear pattern suggests that Burmese amphipithecids were an endemic radiation of hard object feeders that may have been ecological analogues of living New World pitheciin monkeys.     

Taxonomic status of purported primate frontal bones from the Eocene Pondaung Formation of Myanmar

Two isolated cranial fragments from the late middle Eocene Pondaung Formation of central Myanmar have previously been interpreted as frontal bones of the amphipithecid primate Amphipithecus mogaungensis. Aside from a few maxillary fragments, these specimens provide the only potential source of information currently available regarding the cranial anatomy of Amphipithecidae. Were this taxonomic attribution correct, these specimens would indicate that amphipithecids retained numerous primitive skull features, including the absence of a postorbital septum, the retention of a voluminous olfactory chamber, and strong separation between the forebrain and the orbital fossa. However, several anatomical details observable on these specimens are incompatible with their attribution to any primate and strongly suggest that they cannot be ascribed to Mammalia. Particularly problematic in this regard are the extreme thickness of the dermal bone, the odd structure of the alleged "frontal trigon," and the mediolateral orientation and uniquely robust construction of the descending process of the frontal bone (which partially segregates the orbital and temporal fossae). Because these isolated elements can no longer be attributed to Amphipithecus, the anatomical, phylogenetic, and behavioral inferences regarding amphipithecid paleobiology that have been drawn from these specimens can no longer be sustained.     

Agglutinated conical foraminifera from the Lower-Middle Eocene of the Trentinara Formation (southern Italy)

Five taxa of agglutinated conical foraminifera were recorded for the first time in the Trentinara Formation, and two of them are new. Barattolites trentinarensis n. gen. n. sp. shows high conical shape, an eccentric proloculus, trochospiral early chambers, two orders of radial subepidermal partitions and columnar pillars. It is recorded in the Ypresian of Panno Bianco Mt. (Calabria) and in the Ypresian-Lower Lutetian of Serra Pastorella (Basilicata). Pseudochrysalidina (?) variospira n. sp. shows a high conical test, a trochospiral juvenile growth stage, a megalosphere in apical position, and low pillars and chambers in the adult stage. It is known in the Ypresian of Serra Pastorella. Agglutinated conical foraminifera fill the late Lower to early Middle Eocene gap in their Paleogene record. Their very intermittent record is due to their extremely narrow ecological range.     

New primate hind limb elements from the middle Eocene of China

The continued washing, sorting, and identification of middle Eocene (45 Mya) primates from the Shanghuang fissure-fillings (Jiangsu Province, China) have produced additional hind limb elements. All are isolated elements. The strepsirhine hind limb elements include a first metatarsal and a talus, which are appropriate in size and morphology to pertain to Adapoides troglodytes. Adapoides is interpreted as a quadrupedal-climbing (nonleaping) primate with similarities to living lorises and the fossil primate Adapis. The haplorhine hind limb elements are estimated to span a range of adult body sizes from tiny (17 g) to small (200 g). Included among the new sample of haplorhine hind limb specimens is the smallest primate talus reported thus far. These new postcranial specimens expand our understanding of early haplorhine hind limb anatomy and demonstrate additional similarities between Shanghuang eosimiids and other anthropoids.     

Evolutionary relationships of a new genus and three new species of Omomyid primates (Willwood Formation, Lower Eocene, Bighorn Basin, Wyoming)

Studies of new finds of omomyid primates from the lower Eocene Willwood Formation of northwest Wyoming reveal the presence of a new genus and two new species of anaptomorphines and a new species of omomyine. All were apparently short-lived immigrants into the Bighorn Basin. The new genus and speciesTatmanius szalayi is typified by a diminutive single-rooted p3 and a bilobed-rooted p4 with a crown smaller than ml. These traits were probably derived fromPseudotetonius and parallel similar conditions inTrogolemur andNannopithex. The new speciesArapahovius advena is the first occurrence ofArapahovius outside the Washakie Basin, where it appears to have also been a vagrant species.Steinius annectens, sp. nov., is larger than the olderSteinius vespertinus and strengthens the alliance between this genus and BridgerianOmomys carteri, although which species ofSteinius is closer toOmomys is not yet clear. The available evidence suggests a derivation ofOmomys (Omomyini) fromSteinius and all Washakiini from the anaptomorphineTeilhardina, which would indicate that Omomyinae were at least diphyletic. Preliminary evidence suggests that the geographic distributions of at least some Willwood omomyids correlate with paleosol distributions.     

Sedimentary facies of the late Middle Eocene Pondaung Formation (central Myanmar) and the palaeoenvironments of its Anthropoid Primates

The primate-bearing Pondaung Formation (northwestern part of central Myanmar) is mainly composed of cyclic sequences of sandstones and variegated clays that are divisible into 12 lithofacies and are grouped under seven facies associations. These established facies associations represent the deposition in a fluvio-deltaic environment. The anthropoid primate remains occur in swale-fill sediments, sometimes in carbonate nodules of pedogenetic origin and also, in small crevasse channel deposits of the upper part of the Pondaung Formation. The sedimentary facies associated to these anthropoid primates contribute to the understanding of their morpho-anatomic features. To cite this article: A.N. Soe et al., C. R. Palevol 1 (2002) 153–160.     

A new Chalicothere from the Pondaung Formation (late Middle Eocene of Myanmar)

The 2002 field work campaign of the joint Myanmar–French Expedition has resulted in the discovery of new material particularly in the Bahin area (Pondaung Formation, Middle–Upper Eocene, Myanmar). The Nyaung Pin Le outcrop has yielded, among other fossil mammals, a maxillary of a primitive chalicothere, the first ever discovered in the southeastern Asia Palaeogene, which is assigned to the Eomoropidae, Eomoropus pawnyunti nov. sp. This form is distinguished from the other representatives of the family by its small size, its brachyodonty and the few derived shape of the molar ectolophs, nevertheless provided with low mesostyles. To cite this article: J.-A. Remy et al., C. R. Palevol 4 (2005).     

A new anthropoid from the latest middle Eocene of Pondaung, central Myanmar

A new genus and species of medium-sized fossil primate, Myanmarpithecus yarshensis, is described from the lastest middle Eocene sediments of Pondaung, central Myanmar (Burma). The specimens consist of right maxillary fragments with P(4)-M(3)and a left mandibular corpus with C-P(3)and M(2-3). To date, three purported anthropoids have been discovered from the Pondaung Formation: Pondaungia and Amphipithecus (Amphipithecidae) and Bahinia (Eosimiidae). Myanmarpithecus differs from these other Pondaung primates in having cingular hypocones on upper molars and in lacking paraconids on M(2-3). Although Myanmarpithecus resembles some utahiin omomyines in superficial aspects of the morphology of M(2-3)(i.e., mesiodistally compressed molar trigonid and enamel crenulation), the morphological analysis of upper molars and lower premolars indicates that it is neither an omomyoid nor an adapoid but is more derived than fossil prosimians (such as adapoids, omomyoids, and tarsiers) and more anthropoid-like. On the other hand, it is more primitive (prosimian-like) than early anthropoids from the late Eocene/early Oligocene of the Fayum, Egypt. Myanmarpithecus is likely to be an early, primitive anthropoid ("protoanthropoid").     

Anatomy of the bony pelvis of a relatively large-bodied strepsirrhine primate from the late middle Eocene Pondaung Formation (central Myanmar)

Recent survey of the fossiliferous variegated mudstones of the PK1 locality (Sabapondaung) in the late middle Eocene Pondaung Formation (central Myanmar) has led to the recovery of a partial right innominate of a relatively large-bodied primate. Given its size and provenance, this bone probably belongs to the same individual represented by the NMMP 20 primate partial skeleton described previously from the same locality. The new fossil, which preserves the region around the acetabulum and the adjacent part of the ilium, clearly exhibits strepsirrhine rather than anthropoid affinities. This addition to our knowledge of the NMMP 20 partial skeleton allows us to reassess the different locomotor interpretations that have been proposed for this specimen. Aspects of pelvic morphology suggest that the NMMP 20 partial skeleton documents a primate that probably engaged in active arboreal quadrupedalism similar to that practiced by medium-sized Malagasy lemurids rather than lorislike slow moving and climbing. Given the conflicting phylogenetic signals provided by NMMP 39 (a talus showing anthropoid affinities) and NMMP 20 (a partial skeleton bearing adapiform affinities), it appears that two higher-level taxonomic groups of relatively large-bodied primates are documented in the Pondaung Formation. The recent discovery of two taxa of sivaladapid adapiforms from the Pondaung Formation indicates that the assumption that the NMMP 20 partial skeleton belongs to an amphipithecid can no longer be sustained. Instead, this specimen apparently documents a third large-bodied sivaladapid species in the Pondaung Formation.     

Theropithecus atlanticus (Thomas, 1884) (Primates: Cercopithecidae) from the late Pliocene of Ahl al Oughlam, Casablanca, Morocco

The site of Ahl al Oughlam near Casablanca, Morocco, dated to ca. 2·5 Ma, has yielded a good sample of Theropithecus atlanticus (Thomas, 1884), a North African late Pliocene species previously known only by its holotype, a lower molar from Algeria. Theropithecus atlanticus, which can now be much better defined, is clearly distinct from other species of the genus, which is thus more diverse than previously thought. The mandible of T. atlanticus has a very characteristic deep and long post-molar sulcus and a deep and well excavated supra-lateral triangular depression of the ramus, with a sharp postero-inferior ridge. The upper and lower canines are rather large but low. The male P₃is very wide, with well developed posterior crests; the P₄is rounded, with a large talonid and weak notches and clefts. Median lingual notches of the lower molars form an acute angle. Although our incomplete knowledge of T. atlanticus precludes a detailed phylogenetic analysis, we suggest that it arose by clado-genesis from the T. darti–T. oswaldi lineage; it is replaced by the latter species in the Pleistocene.Le gisement de Ahl al Oughlam près de Casablanca (Maroc), daté d'environ 2,5 Ma, a livré une belle collection deTheropithecus atlanticus (Thomas, 1884), espèce du Pliocène supérieur nord-africain qui n'était jusque là connue que par son holotype, une molaire inférieure d'Algérie. T. atlanticus, qui peut maintenant être bien mieux défini, se distingue bien des autres espèces du genre, dont la diversité est ainsi accrue. La mandibule de T. atlanticus est très caractéristique par son espace rétro-molaire vaste et profond, et sa dépression supra-latérale de la branche montante également très profonde, avec un rebord inférieur aigu. Les canines supérieures et inférieures sont grosses mais basses. La P₃mâle est très large, avec des crêtes postérieures très développées; la P₄est arrondie, avec un grand talonide et des sillons peu profonds. Sur les molaires inférieures, le débouché de la vallée médiane forme un angle aigu. Bien que notre connaissance imparfaite de T. atlanticus interdise une analyse phylétique détaillée, nous suggérons une dérivation par cladogenèse à partir de la lignée T. darti–T. oswaldi; cette dernière espèce le remplace au Pléistocène.     

中国兰科独蒜兰属植物增补

报道了中国兰科独蒜兰属2个未详知种:藏南独蒜兰(Pleione arunachalensis Hareesh, P.Kumar M.Sabu)和矮小独蒜兰[P.humilis (Sm.) D.Don],并提供了详细的形态描述和照片。凭证标本保存于云南省林业和草原科学院植物标本馆(YAF)。     

中国兰科植物研究杂记(英文)

报道了中国兰科植物一新记录种互生对叶兰[Neottia alternifolia(KingPantl.)Szlach.];并对紫婉石斛(Dendrobium transparens Wall.ex Lindl.)的形态特征、生境等进行了描述。紫婉石斛与兜唇石斛[Dendrobium aphyllum(Roxb.)C.E.Fischer]相似,区别在于唇瓣中央具深紫红色大斑块,唇瓣正面具柔毛;互生对叶兰是鸟巢兰属自养类型种类中唯一具有两片互生叶的种类,极易同该属其他种类区分。     

Proximal femoral anatomy of a sivaladapid primate from the late middle Eocene Pondaung formation (central Myanmar)

The postcranial anatomy of the Asian sivaladapid adapiforms is still virtually undocumented, whereas dental remains of these primates have been known for several decades. Little is known about their positional behavior as a result. In this article, we describe a partial left femur of a medium-sized primate preserving its entire proximal portion and a significant length of its shaft. This fossil was recently recovered from the fossiliferous locality of Thamingyauk in the late middle Eocene Pondaung Formation (central Myanmar). This femur is considered to pertain to the same individual as two tarsal elements (fragmentary talus and calcaneus) from the same locality (same location), and attributed to a medium-sized sivaladapid adapiform primate (Kyitchaungia takaii). This new postcranial element provides the first documentation of femoral anatomy among Sivaladapidae from Asia. The mechanical implications deriving from the musculoskeletal interpretation of this bone indicate an animal that probably engaged in a kind of active arboreal quadrupedalism with some degree of proficiency in leaping. Even though many musculoskeletal aspects suggest that branch walking and running were important parts of its locomotor repertoire, in other details it appears that relatively complex movements at the hip joint were actually possible and probably associated with climbing or some hindlimb suspensory activities.