Nichollsemys

Nichollsemys; Temporal range: Early Cretaceous–Late Cretaceous; 84.9–70.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N
	Skull, Royal Tyrrell Museum in Alberta, Canada
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Cryptodira
Superfamily:	Chelonioidea
Genus:	†Nichollsemys; , 2006
Species
	†N. baieri (Brinkman, 2006);

Nichollsemys is a genus of extinct sea turtles. The only known species is Nichollsemys baieri.^[2]

Taxonomy[]

Biostratigraphy and paleobiogeography of Late Cretaceous chelonioids of North America, with Nichollsemys (1) at upper left

Fossils of the Nichollsemys have been found in Alberta, Canada, by Donald Brinkman.^[3] The fossils found are all skulls.

The name of Nichollsemys is a tribute to Elizabeth Nicholls, a paleontologist from Canada who studied marine reptiles from the Triassic period. She had previously done work with Brinkman when they found the ichthyosaur genus Pattinatator.^[4]

Evolution[]

Panchelonioidea

†Toxochelys

†Protostegidae

Chelonioidea

†Corsochelys

Dermochelyidae

†Nichollsemys

†Allopleuron

Cheloniidae

†Argillochelys

†Procolpochelys

	†Eochelone

	†Puppigerus

	†Ctenochelys

	†Peritresius

	†Cabindachelys

Description[]

The full length of the Nichollsemys is unknown, but Brinkman made a chart of the length of some parts of the specimen. The length from the basioccipital to the premaxilla measures 11.4 cm, the width of all the quadrates measures 9.8 cm, the depth at level of the quadrates measures 7.1 cm, the intraorbital width measures 2 cm, and the length measures 3.6 cm. ^[5] The cranium has many things in common with that of Toxochelys: for example, they both have a rostrum basisphenoidale shaped like a rod.

References[]

^ Brinkman, D. (2006), A primitive chelonioid turtle from the late Campanian of North America
^ Global Biodiversity Information Facility, 2019: Nichollsemys (Brinkman, Hart, Jamniczky & Colbert, 2006)
^ Fossilworks, 2013: Nichollsemys (Behrensmeyer, A. K., and Turner, A.)
^ Paleofile: Nichollsemys. Accessed 16 June 2020
^ Brinkman, Donald B, et al.: "Measurements of the Skull of Nichollsemys Baieri." Research Gate, Sept. 2006

[1] Brinkman, D. (2006), A primitive chelonioid turtle from the late Campanian of North America

[2] Global Biodiversity Information Facility, 2019: Nichollsemys (Brinkman, Hart, Jamniczky & Colbert, 2006)

[3] Fossilworks, 2013: Nichollsemys (Behrensmeyer, A. K., and Turner, A.)

[4] Paleofile: Nichollsemys. Accessed 16 June 2020

[5] Brinkman, Donald B, et al.: "Measurements of the Skull of Nichollsemys Baieri." Research Gate, Sept. 2006

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