A description of a Denazinemys nodosa specimen (Testudinata, Baenidae) from the Late Cretaceous Kaiparowits Formation of southern Utah

Abstract

Denazinemys nodosa is a Late Cretaceous representative of the North American turtle clade Baenidae diagnosed, among others, by a shell surface texture consisting of raised welts. We provide a detailed description of a partial skeleton from the late Campanian Kaiparowits Formation of Utah, USA, including bone-by-bone analysis of its cranium based on images obtained using micro-computed tomography. A revised phylogenetic analysis confirms placement of Denazinemys nodosa close to Eubaena cephalica and Boremys spp. within the clade Eubaeninae. Comparison with a second skull from the Kaiparowits Formation previously assigned to Denazinemys nodosa questions its referral to this taxon. An assortment of specimens from the Early to Late Campanian of Mexico and the USA had previously been referred to Denazinemys nodosa based on shell surface texture alone, even though this characteristic is known to occur in other baenids. Our review of all available material concludes that Denazinemys nodosa is currently only known from the Late Campanian of New Mexico and Utah.