First middle Miocene sivaladapid primate from Thailand.
Sivaladapids are a group of Asian adapiform primates that were previously documented from deposits dating to the middle Eocene through the late Miocene in Pakistan, India, Myanmar, Thailand, and China. The group is notable for the persistence of three genera, Sivaladapis, Indraloris and Sinoadapis, into the late Miocene. In Thailand, sivaladapids were previously documented only from late Eocene deposits of the Krabi mine. Here, we describe the first Southeast Asian Miocene sivaladapid, Siamoadapis maemohensis gen. et sp. nov. from a 13.3 to 13.1 Ma lignite layer from the Mae Moh coal mine, Thailand. It differs from other Miocene sivaladapids by its distinctly smaller size and in features of the dentition. This discovery enhances the paleoecological diversity of the middle Miocene primate fauna of Thailand, which now includes sivaladapids, a loris, tarsiids, and hominoids. In this respect, the fossil primate community from the middle Miocene of Thailand is similar in its composition to roughly contemporaneous assemblages from southern China, India, and Pakistan. However, the Thai fossils represent a distinct genus, suggesting a different biogeographic province with distinctive paleoenvironments.
Chaimanee
Yaowalak
Y
Department of Mineral Resources, Paleontological Section, Bureau of Paleontology and Museum, Rama VI Road, Bangkok 10400, Thailand. yaowalak@dmr.go.th
Yamee
Chotima
C
Tian
Pannipa
P
Chavasseau
Olivier
O
Jaeger
Jean-Jacques
JJ
D000818:Animals; D003817:Dentition; D005580:Fossils; D055593:Geological Phenomena; D005844:Geology; D008334:Mandible / Q000033:anatomy & histology; D011323:Primates / Q000033:anatomy & histology*; D013785:Thailand