''Prionochelys'' is an extinct genus of pancheloniid from the Mooreville Chalk and Eutaw Formations of

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

. It consists of a single species, ''P. matutina''.

Taxonomy

''Prionochelys'' was originally assigned to the family Toxochelyidae. A 2018 paper found it to be on the stem of Chelonioidea, the family to which most modern

sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerh ...

s belong, forming a

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

grouping named as

Ctenochelyidae Ctenochelyidae is an extinct family of sea turtles which lived in North America during the Santonian-Maastrichtian stages of the Late Cretaceous. Classification The family is defined as a monophyletic clade arising from the most recent ancestors ...

with '' Ctenochelys'' and ''

Peritresius ''Peritresius'' is an extinct genus of sea turtle from the Late Cretaceous deposits in the US Eastern Seaboard. Taxonomy Two species are known, ''Peritresius ornatus'' (Leidy, 1856) and ''P. martini'' Gentry, Parham, Ehret, and Ebersole, 2018, b ...

''. Below is a

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

from the analysis by Gentry, Ebersole & Kiernan (2019):

References

{{Taxonbar, from=Q123907448 Late Cretaceous turtles of North America Chelonioidea Prehistoric turtle genera