A new primitive eucryptodiran turtle from the Upper Jurassic Phu Kradung Formation of the Khorat Plateau, NE Thailand

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.

A new freshwater teleosaurid from the Jurassic of northeastern Thailand

“…Phunoichelys thirakhupti (Tong et al, 2015) and another as-yet-undescribed xinjiangchelyid, is distinct from other assemblages placed in the upper part of the Phu Kradung Formation, which include abundant remains of trionychoid turtles such as Basilochelys macrobios (Tong et al, 2009). Known since the Middle Jurassic, xinjiangchelyids are a dominant turtle group in the Late Jurassic of Asia (Central Asia and China), whereas records of this group in Early Cretaceous deposits are scarce in mainland Asia.…”

“…The deposit shows evidence of aerial exposure with paleosol development and insect burrows (Martin et al, 2016) and in addition to the teleosaurids, contains a known fauna of both aquatic and terrestrial vertebrates. These include hybodont sharks (Cuny et al, 2014), the ginglymodian fish Isanichthys lertboosi , the xinjianchelyid turtle Phunoichelys thirakhupti (Tong et al, 2015) an undescribed freshwater turtle, ornithopods (Buffetaut et al, 2014), theropods (Chanthasit, 2011), and undescribed remains of sauropod dinosaurs, temnospondyls, and pterosaurs (Buffetaut et al, 2015).…”

The first South American sandownid turtle from the Lower Cretaceous of Colombia

“…Pan-cryptodires (sensu Joyce, Parham & Gauthier, 2004 ) represent globally distributed and highly diverse turtles with a wide spectrum of environmental adaptations (coastal-littoral, freshwater, and terrestrial) and body-plan (e.g., Pérez-García, 2012 ; Anquetin, Püntener & Billon-Bruyat, 2014 ; Jansen & Klein, 2014 ; Rabi et al, 2014 ; Tong et al, 2014 ; Anquetin, Püntener & Billon-Bruyat, 2015 ; Zhou & Rabi, 2015 ). Among pan-cryptodires, Sandownidae is a very particular group of turtles, formed by four taxa, including: Sandownia harrisi ( Meylan et al, 2000 ) from the Aptian of the Isle of Wight, England; Angolachelys mbaxi ( Mateus et al, 2009 ) from the Turonian of Angola; an unnamed turtle (“the Glen Rose turtle”) from the Albian Glen Rose Formation of Texas ( Barck, 1992 ; Vineyard, 2009 ), and Brachyopsemys tingitana ( Tong & Meylan, 2013 ) from the Early Paleocene (Danian) of Morocco.…”

Kalasinemys, a new xinjiangchelyid turtle from the Late Jurassic of NE Thailand

“…The first basal cryptodiran turtle from SE Asia, Siamochelys peninsularis, closely related to xinjiangchelyids, was reported from the Jurassic of the southern peninsula of Thailand (Tong et al 2002). More recently, remains of a xinjiangchelyid turtle, Phunoichelys thirakhupti Tong, Naksri, Buffetaut, Suteethorn, Suteethorn, Deesri, Sila, Chanthasit and Claude, 2015, were reported from the Upper Jurassic Phu Kradung Formation at the Phu Noi locality (Kalasin Province) in NE Thailand (Tong et al 2015b). In this paper, we describe a second xinjiangchelyid turtle taxon from Phu Noi locality.…”

“…The material is housed in Sirindhorn Museum, Sahatsakhan, Kalasin Province, Thailand. For more geological information about Phu Noi locality, see Tong et al (2015b).…”