The Plesiochelyidae are an extinct family of

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...

s in the clade

Thalassochelydia Thalassochelydia is a clade of extinct marine turtles from the Late Jurassic and earliest Cretaceous of Europe and South America. The group is defined as including ''Eurysternum'', ''Plesiochelys'' and ''Thalassemys'' to the exclusion of '' Pel ...

originally classified within the

Cryptodira The Cryptodira ('' el, hidden neck'') are a suborder of Testudines that includes most living tortoises and turtles. Cryptodira differ from Pleurodira (side-necked turtles) in that they lower their necks and pull the heads straight back into the ...

suborder, mostly belonging from the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

period. An alternate study placed the clade Thalassochelydia in the

Angolachelonia Angolachelonia is a clade of extinct turtles from the Late Jurassic to Paleogene of Eurasia. The group is defined as all taxa derived from the ancestor of the type genus ''Angolachelys'' and '' Solnhofia'', a definition that could potentially e ...

and outside the

Testudines Turtles are an order (biology), order of reptiles known as Testudines, characterized by a special turtle shell, shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) an ...

.Evers, S. W., & Benson, R. B. (2019). A new phylogenetic hypothesis of turtles with implications for the timing and number of evolutionary transitions to marine lifestyles in the group. Palaeontology, 62(1), 93-134.

References

Late Jurassic turtles Prehistoric reptile families {{paleo-turtle-stub