Wu, Miao, Chang, Shi & Wang, 2017
Understanding the Tibetan Plateau’s palaeogeography and palaeoenvironment is critical for reconstructing Asia’s climatic history; however, aspects of the plateau’s uplift history remain unclear. Here, we report a fossil biota that sheds new light on these issues. It comprises a fossil climbing perch (Anabantidae) and a diverse subtropical fossil flora from the Chattian (late Oligocene) of central Tibet. The fish, Eoanabas thibetana gen. et sp. nov., is inferred to be closely related to extant climbing perches from tropical lowlands in south Asia and sub-Saharan Africa. It has osteological correlates of a labyrinth organ, which in extant climbing perches gives them the ability to breathe air to survive warm, oxygen-poor stagnant waters or overland excursion under moist condition. This indicates that Eoanabas likewise lived in a warm and humid environment as suggested by the co-existing plant assemblage including palms and golden rain trees among others. As a palaeoaltimeter, this fossil biota suggests an elevation of ca. 1,000 m. These inferences conflict with conclusions of a high and dry Tibet claimed by some recent and influential palaeoaltimetry studies. Our discovery prompts critical re-evaluation of prevailing uplift models of the plateau and their temporal relationships with the Cenozoic climatic changes.
Teleostei Müller, 1845
Anabantiformes sensu Wiley and Johnson, 2010
Anabantoidei sensu Lauder and Liem, 1983
Anabantidae Bonaparte, 1839
Eoanabas thibetana gen. et sp. nov.
Etymology. The generic name combines ‘Eo-’ (Greek, early/primeval) with ‘Anabas’, the type genus of Anabantidae from tropical Asia. The specific name refers to Tibet, China.
Holotype. IVPP V 22782, a complete skeleton, part and counterpart (Fig. 1a,b).
Paratypes. Sixteen specimens are designated as paratypes (Supplementary Information).
Locality and Horizon. Jiangnongtangga (type locality) and Songwori in south Nima Basin and Dayu in Lunpola Basin in central Tibet (Supplementary Figs 1 and 2). Middle-upper part of Dingqing Formation, late Oligocene (Chattian) (ca. 26~23.5 Ma)6, 20, 26.
Diagnosis. A labyrinth fish displaying anabantid characteristics including a posterior notch of the opercle bounded by spines, a V-shaped strut on inner side of opercle and six to nine anal-fin spines. It shares with Asian anabantids the following derived characters: broad infraorbitals 3–5 completely covering the cheek, a sensory canal pore just behind sphenotic/pterotic junction and pelvic plate lying flat; and it shares with African anabantids some derived characters, e.g., sensory canal opening in between the infraorbitals, supraorbital commissure of the sensory canal absent and male postocular contact organ present.
Feixiang Wu, Desui Miao, Mee-mann Chang, Gongle Shi and Ning Wang. 2017. Fossil Climbing Perch and Associated Plant Megafossils indicate A Warm and Wet Central Tibet During the late Oligocene. Scientific Reports. 7, Article number: 878. DOI: 10.1038/s41598-017-00928-9