Biology:Denazinemys

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Short description: Extinct genus of turtles

Denazinemys
Temporal range: Late Cretaceous, 74.56–73.04 Ma
Scientific classification e
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Pantestudines
Clade: Testudinata
Clade: Paracryptodira
Family: Baenidae
Clade: Baenodda
Genus: Denazinemys
Lucas and Sullivan, 2006
Species

D. nodosa (Gilmore, 1916)

Synonyms[1]

"Baena" nodosa Gilmore, 1916

Denazinemys was a genus of baenid turtle that lived in the Late Cretaceous of New Mexico. The holotype specimen, which D. nodosa was based on, USNM 8345, consists of a partial carapace and plastron. It came from the De-na-zin Member of the Kirtland Formation, and therefore, Denazinemys lived in the Kirtlandian land-vertebrate age. Many specimens other than the holotype have been assigned to Denazinemys.[1]

Numerous shell fragments from the Lower and the Middle Campanian were assigned to Denazinemys nodosa, based on the welted structure of the shell surface. However, a recent study calls into question the attribution of this material to Denazinemys nodosa, as the material is too fragmentary to distinguish differences in the structure of the welted shell surface.[2] As it is not yet possible to identify these fragments precisely (several species of baenidae having this same feature on their shell surface), the researchers restricted Denazinemys nodosa to the Upper Campanian.[2]

Distinguishing characteristics

Previously, Scabremys ornata was assigned to Denazinemys as D. ornata. Below are the features found in Denazinemys distinguishing the two genera:[1]

  • a carapace that is sub-triangular with widest dimension posteriorly;
  • prepleurals present and touching the first vertebrae medially;
  • the first vertebrae an irregular hexagonal shape with the greatest width posteriorly, contacting anterior second vertebrae;
  • extracervicals lateral to the primary cervicals, the cervicals being sub-divided;
  • and carapace nodes irregular and not forming distinct ridges.

Classification

Denazinemys is a baenid along with Plesiobaena, Boremys, Scabremys, Baena and Chisternon.[1]

Below is a cladogram made by Sullivan et al. in 2013 showing the relations of Denazinemys: (note: Boremys pulchra is partly a junior synonym of Boremys grandis)[1]

Baenidae

hypothetical ancestor

Neurankylus eximius

Trintichelys hiatti

Baenodda

Plesiobaena antiqua

Scabremys ornata

Boremys pulchra

Chisternon undatum

Baena arenosa

Denazinemys nodosa

References

Wikidata ☰ Q15738349 entry