Plastomenus belongs to the clade
Pantrionychidae, represented by
softshell turtles in modern times. It is the
type genus of the
subfamily Plastomeninae (also treated as the family Plastomenidae), a group of extinct turtles that lived from the
Late Cretaceous to the
Eocene. The following species are known: • †
P. joycei Lyson, Petermann & Miller, 2021 -
Early Paleocene of Colorado, USA (
Denver Formation)
Phylogeny Based on Joyce & Lyson (2017): }}Alternatively,
Plastomenus may be most closely related to
Gilmoremys. ==Description==