Friday, August 8, 2014

[Paleontology • 2014] 'เต่าภูน้อย' ภูน้อยเซลีส ธีรคุปติ | Phunoichelys thirakhupti • A New Primitive Eucryptodiran Turtle from the Upper Jurassic Phu Kradung Formation of the Khorat Plateau, Northeastern Thailand



Figure 1. Phunoichelys thirakhupti gen. et sp. nov. from the Phu Kradung Formation (latest Jurassic) of Phu Noi Locality, NE Thailand.
(a–c) PRC 230 (holotype), shell in dorsal (a, b) views, and detail of ornamentation on carapace (c);
(g–m) PRC 232, (g–i) right costal 1 (PRC232-1) in dorsal (g, h) and ventral (i) views; (j, k) left costal 4 (PRC232-5), (l, m) left costal 6 (PRC232-6).
Scale bar = 5 cm for (a), (b), (d), (e) and (g–m), 1 cm for (c) and (f).
Figure 3. Reconstruction of the shell of Phunoichelys thirakhupti gen. et sp. nov. from the Phu Kradung Formation (latest Jurassic) of Phu Noi Locality, NE Thailand. (a) Carapace in dorsal view; (b) plastron in ventral view.


Abstract
A new genus and new species of primitive eucryptodiran turtle, Phunoichelys thirakhupti gen. et sp. nov., is described on the basis of shell remains from the lower part of the Phu Kradung Formation, at Phu Noi locality, Kalasin Province, NE Thailand. It is assigned to Xinjiangchelyidae on the basis of the marginals covering the lateral end of the costals and the anal scutes invading the hypoplastra. The new taxon is further characterized by a low and rounded carapace without a cervical notch; the whole carapace and plastron covered with a clear ornamentation consisting of tiny irregular vermiculated furrows; a complete neural series that reaches the suprapygal; a very wide and short cervical scute; relatively wide vertebral scutes; and a long first thoracic rib that extends along the full width of the first costal. The sutured plastron/carapace connection and the marginals covering the lateral end of the second to seventh costals suggest that the turtles from Phu Noi may be related to some primitive xinjiangchelyids from the Sichuan Basin. The discovery of a xinjiangchelyid turtle in the lower part of the Phu Kradung Formation supports a Late Jurassic age for that part of the formation.

Keywords: Testudines; Eucryptodira; Xinjiangchelyidae; Phunoichelys thirakhupti; Late Jurassic; Phu Kradung Formation; NE Thailand

Figure 3. Reconstruction of the shell of Phunoichelys thirakhupti gen. et sp. nov. from the Phu Kradung Formation (latest Jurassic) of Phu Noi Locality, NE Thailand. (a) Carapace in dorsal view; (b) plastron in ventral view.


 


Haiyan Tong, Wilailuck Naksri, Eric Buffetaut, Varavudh Suteethorn, Suravech Suteethorn, Uthumporn Deesri, Saitong Sila, Phornphen Chanthasit and Julien Claude. 2014. A New Primitive Eucryptodiran Turtle from the Upper Jurassic Phu Kradung Formation of the Khorat Plateau, NE Thailand. Geological Magazine. in press. doi: dx.doi.org/10.1017/S0016756814000223

A xinjiangchelyid eucryptodiran. The type species is Phunoichelys thirakhupti box.com

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