Data from: A new platychelyid turtle (Pan-Pleurodira) from the Late Jurassic (Kimmeridgian) of Oaxaca, México

Until recently, the record of Mesozoic turtles in Mexico has been
restricted to the Cretaceous. New discoveries in the Sabinal Formation
(Tlaxiaco, Oaxaca) have extended the record into the Kimmeridgian (Late
Jurassic). The Sabinal Formation is part of the Tlaxiaco Basin, which was
a depocenter of continental and marine sediments dominated by
transgressive-regressive marine conditions during the Jurassic–Cretaceous.
The new turtle described here consists of an almost complete carapace
associated with a plastron. Based on the unique combination of characters,
this turtle is identified as a new species of Platychelyidae here named
Notoemys tlaxiacoensis. Platychelyid characters in this specimen include
the presence of the sulcus between vertebral 3 and 4 located on neural 6,
the presence of a central plastral fontanelle, and a pair of reduced
mesoplastra. The occurrence of Kimmeridgian platychelyids in Mexico
confirms that the Hispanic Corridor acted as a connection between Tethyan
and Palaeopacific faunas.