Kappachelys okurai gen. et sp. nov., a New Stem Soft-Shelled Turtle from the Early Cretaceous of Japan

The first soft-shelled turtle from the Jehol Biota of China

“…The Maortu turtles have since been shown to be Late Cretaceous in age (Brinkman et al, 2008). Fragmentary shell remains have recently been described from the Hauterivian to Albian of Japan under the name Kappachelys okurai that show the incipient shell microstructure of extant trionychids and therefore represent the basal stem lineage of the group (Hirayama, 2005;Nakajima et al, 2009;Hirayama et al, 2013). Although the results of our analysis are disappointing in that the phylogenetic placement of Perochelys lamadongensis is unclear, it is nevertheless apparent that this taxon is among the first turtles with modern trionychid characteristics.…”

Cretaceous Trionychids of Asia: An Expanded Review of Their Record and Biogeography

“…For this reason, we previously suggested that Trionyx zakhidovi be considered a nomen dubium within Trionychidae (Danilov and Vitek 2009;Vitek and Danilov 2010). Referred specimens: FPDM-V127, fragmentary costal (Hirayama et al 2012, Fig. 6A) from Katsuyama, Fukui Prefecture, Japan, Kitadani Formation, Tetori Group, Barremian or Aptian (Hirayama 2002;Hirayama et al 2012).…”

“…Referred specimens: FPDM-V127, fragmentary costal (Hirayama et al 2012, Fig. 6A) from Katsuyama, Fukui Prefecture, Japan, Kitadani Formation, Tetori Group, Barremian or Aptian (Hirayama 2002;Hirayama et al 2012).…”

“…Here we expand upon that work with photographs, illustrations, or reconstructions of the most important specimens and add information for each taxon. Our review does not include undescribed or figured trionychid specimens or occurrences mentioned by Gilmore (1931), Kordikova (1994a), Nessov (1997), Khosatzky (1999), Hirayama et al (2000), and Lapparent de Broin (2004) or any stem-trionychid or trionychoid material from the Akaiwa Formation (late Neocomian or Barremian) of Japan (Hirayama 2008;Hirayama et al 2012).…”

A new trionychid turtle from the Early Cretaceous of Heilongjiang Province, Northeastern China

“…In the crown group of turtles, the Trionychidae is the most ancient family (Krenz et al, 2005;Near, Meylan & Shaffer, 2005;Lourenço et al, 2012;Joyce et al, 2013), with the oldest record from the Early Cretaceous (Hirayama, 2005;Hirayama et al, 2013). The Early Cretaceous trionychid turtle record is scarce, all softshelled turtles from that epoch are known only from Asia, but often with poorly preserved material, so their exact systematic position is not well resolved .…”