Macrochelys temminckii

Thomas, Travis M., Granatosky, Michael C., Bourque, Jason R., Krysko, Kenneth L., Moler, Paul E., Gamble, Tony, Suarez, Eric, Leone, Erin, Enge, Kevin M. & Roman, Joe, 2014, Taxonomic assessment of Alligator Snapping Turtles (Chelydridae: Macrochelys), with the description of two new species from the southeastern United States, Zootaxa 3786 (2), pp. 141-165 : 149

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.

Figures

FIGURE 9. Bayesian inference phylogeny for extant chelydrids (Chelydra and Macrochelys). Note that representative skeletal synapomorphies in skull and carapace (above and below, respectively, next to lineage name) are provided for each lineage of Macrochelys; values above major nodes represent posterior probabilities (≥ 95 %); values below major nodes represent the mean divergence time estimation of the most recent common ancestor (MRCA); and bars at major nodes represent 95 % Highest Posterior Density (HPD).