Ocepechelon

Ocepechelon is an extinct genus of giant protostegid sea turtle known from Late Cretaceous (late Maastrichtian stage, 67 Myr) phosphatic deposits of the Oulad Abdoun Basin, Khouribga Province of Morocco. It is known from the holotype OCP DEK/GE 516, a complete but isolated 70-cm-long skull, making it one of the largest marine turtles ever described. It was first named by Nathalie Bardet, Nour-Eddine Jalil, France de Lapparent de Broin, Damien Germain, Olivier Lambert and Mbarek Amaghzaz in 2013 and the type species is Ocepechelon bouyai. The feeding apparatus of Ocepechelon, a bony pipette-like snout, is unique among tetrapods and shares unique convergences with both syngnathid fishes (unique long tubular bony snout ending in a rounded and forward directed mouth) and beaked whales (large size and elongated edentulous jaws).[1]

Ocepechelon Temporal range: Maastrichtian ~67 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Skull and size comparison of Ocepechelon
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Cryptodira
Clade:	Panchelonioidea
Family:	†Protostegidae
Genus:	†Ocepechelon Bardet et al, 2013
Type species
†Ocepechelon bouyai Bardet et al, 2013

Phylogeny

Bardet et al (2013) originally described Ocepechelon as a dermochelyid turtle.[1] Scavezzoni & Fischer (2018) and Evers et al. (2019), however, found it to be a protostegid.

Evers et al. (2019):[2]

Panchelonioidea

†Toxochelys      †Protostegidae      †Desmatochelys       †Ocepechelon       †Archelon     †Protostega           †Calcarichelys     †Bouliachelys       †Chelosphargis       †Santanachelys     †Notochelone     †Rhinochelys          Chelonioidea    †Corsochelys     Dermochelyidae       †Nichollsemys       †Allopleuron       Cheloniidae       †Argillochelys     †Procolpochelys       †Eochelone     †Puppigerus         †Ctenochelys     †Peritresius     †Cabindachelys

References

1. Bardet, N.; Jalil, N. E.; De Lapparent De Broin, F.; Germain, D.; Lambert, O.; Amaghzaz, M. (2013). Viriot, Laurent (ed.). "A Giant Chelonioid Turtle from the Late Cretaceous of Morocco with a Suction Feeding Apparatus Unique among Tetrapods". PLoS ONE. 8 (7): e63586. Bibcode:2013PLoSO...863586B. doi:10.1371/journal.pone.0063586. PMC 3708935. PMID 23874378.
2. Evers, Serjoscha W.; Barrett, Paul M.; Benson, Roger B. J. (2019-05-01). "Anatomy of Rhinochelys pulchriceps (Protostegidae) and marine adaptation during the early evolution of chelonioids". PeerJ. 7: e6811. doi:10.7717/peerj.6811. ISSN 2167-8359. PMC 6500378. PMID 31106054.