[1] Basilemys has been found in rocks dating to the Campanian and Maastrichtian subdivisions of the Late Cretaceous and is considered to be the largest terrestrial turtle of its time.

[4] Many paleontologists have described the behaviors of Basilemys to likely be comparable to that of tortoises, due to living in terrestrial habitats and consuming tough plants.

[4] Basilemys is easily distinguishable from other fossil turtles due to how thick its shell is, the intricate sculpture of rows of triangular tubercles separated by pits, and its reduced inframarginal scales.

[1] Turtles were prominent members of the Upper Cretaceous and thus, their specimens found throughout North America are useful in defining biogeographic patterns.

[1] In another part of Canada, a Basilemys specimen from the Frenchman Formation of Saskatchewan retained most of the neck and cranial fragments.

[6] Other shell fragments of Basilemys have been found in the El Gallo Formation, located in Baja California.

[5] The three shell fragments that were found in the El Gallo Formation represent the first record of Basilemys from the Upper Cretaceous of Mexico.

[1] The ventro-posterior corner of Basilemys' skull lacks a posterior projection into the temporal emargination which is unlike the genus Adocus.

[1] Near the center of individual bones, the skull roof of Basilemys is developed and there are striations that extend outwards from these central regions.

[1] In addition, the premaxillae of Basilemys are paired instead of fused to form a single element like in the Trionychia superfamily.

[1] The triturating surface of the maxilla is visible on both sides of the skull of Basilemys and has a well developed maxillary tooth.

The surface texture of a Basilemys carapace consists of many small, shallow pits that are arranged in a chain-link pattern.

[8] The sample from the North American Basilemys showcased a highly organized “spindle-shaped” ornamentation pattern.