Macrochelys temminckii (Troost in Harlan 1835)

Common name. Alligator Snapping Turtle

Holotype. MNHN-AC A. 4540, “collected near Memphis” (skull also figured in Bour 1987). (Western lineage; Figure 9).

Amended diagnosis. Carapacial caudal notch narrow and triangular or U-shaped, contained wholly on the pygal and not extending onto peripheral set 11, and pygal with two serrations and without medial suture; Peripheral 11 with 1 serration; pleural scute set 1 does not overlap onto the nuchal; distal rib end of costal 1 enters middle of peripheral 3; posterior projection of the squamosal globular and obtusely angled in lateral aspect, usually upwardly inflected; dermal scale on the frontals reduced in size; processus trochlearis oticum relatively straight with a single distal protuberance; posterior margin of squamosal-opisthotic contact relatively straight in dorsal aspect; mandible relatively narrow with slender triturating surfaces. Although generally the caudal notch is small and triangular, observable variation occurs within the species.