Psephophorus

Psephophorus Temporal range: Oligocene-Pliocene
Skull (LACM 162552) of P. sp. at the Natural History Museum of Los Angeles County
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Cryptodira
Superfamily:	Chelonioidea
Family:	Dermochelyidae
Genus:	†Psephophorus von Meyer, 1847
Type species
†P. polygonus
Species
†P. polygonus †P. calvertensis †P. eocaenus †P. oregonesis †P. californiensis †P. terrypratchetti †P. rupeliensis †P. scaldii

Psephophorus is an

Psephophorus is the only Miocene dermochelyid turtle found in Europe.^[6] One species of Psephophorus could measure up to ten feet in length.^[7]

Discovery and identification

Von Meyer originally named Psephophorus in 1846.

• Psephophorus polygonus is the type
  Fossils of the species have shown bony, carapacial ridges, adjacent, small and polygonal bony ossicles which measure about 22 × 25 mm.^[10] When the ossicles extend further along the longitudinal axis, their size increases up to an average of 33 × 41 mm.^[10]
• Psephophorus calvertensis was first named by Palmer in 1909.[12] It was so named for being found in the Calvert Formation.^[13] P. calvertensis is a rarely found specimen.^[13]
• Psephophorus eocaenus was first named by Andrews in 1901.^[14]
• Psephophorus californiensis was first named by Gilmore in 1937.^[3]
• Psephophorus terrypratchetti was discovered in the 1990s by
  a giant turtle.^[1] This species reached 2.3–2.5 m (7.5–8.2 ft) in body length which is more than 80% bigger than P. eocaenus.^[1]