[1] During the early 1980s, addition turtle specimens from the Kayenta Formation were collected by field parties from the University of California Museum of Paleontology (UCMP), which were reported by Clark & Fastovsky (1986) prior to the naming of Kayentachelys.

Derived features shared with early turtles like Proterochersis and cryptodirans include an antrum postoticum of the squamosal, a fused basipterygoid articulation, and 11 peripheral osteoderms.

[1] When Kayentachelys was first described by Gaffney et al. (1987), it was classified as the oldest and earliest branching cryptodiran turtle and the sole taxon within a new clade called Kayentachelyidae.

[8][9] Below is a cladogram depicting the phylogenetic hypothesis from Sterli and Joyce (2007): †Proganochelys †Paleochersis †Proterochersis †Kayentachelys †Mongolochelys †Kallokibotion Panpleurodira †Paracryptodira Eucryptodira Kayentachelys is known only from the "silty facies" of the Kayenta Formation in northeastern Arizona.

Despite extensive outcrop of the "typical facies" of the Kayenta Formation in Utah, Colorado, and northern Arizona, vertebrate fossils are rare in these regions.

Vertebrate fossils from the "silty facies" of the Kayenta Formation are most abundantly known from Ward Terrace along the Adeii Eechii Cliffs southeast of Tuba City, AZ on the lands of the Navajo Nation.

[10] Kayentachelys was initially interpreted as an aquatic turtle, based upon the sharp tapered edges of the low-domed shell and the lack of both limb armor and sculpturing on the carapace.