Table 1.
Selected morphological characters in the genera composing the tribe Sonorini. Diagnostic differences with Yakacoatl are in grey. *Denotes qualitative characters, while ºmeristic characters.
Fig 1.
Phylogenetic relationships of the tribe Sonorini.
Numbers at the nodes represent ultrafast bootstrap values. Heads at the tips are intended to be illustrative and are not at the same scale.
Fig 2.
Yakacoatl tlalli (holotype, MZFC-HE 37100, 381 mm total length), dorsal (left) and ventral (right) aspects of the preserved specimen.
Note the difference in size between the dorsal scales of the body and those from the tail. The scale bar represents centimeters.
Fig 3.
Location of the Y. tlalli type locality (red dot, A).
Rural construction where the holotype (MZFC-HE 37100) was found (B); typical vegetation at the type locality (C). Photographs of the type locality were taken by OOL, shape files used to construct the map were obtained from INEGI (Instituto Nacional de Estadística y Geografía, Mexico).
Fig 4.
Hemipenis of Yakacoatl tlalli (A) and Pseudoficimia frontalis (B), a closely related Sonorini according to our phylogenetic tree.
Sulcate and asulcate views are presented as left and right, respectively. Scale bar represents millimeters.
Fig 5.
Dorsal (A), lateral (B), and ventral (C) views of the head of the holotype of Yakacoatl tlalli (MZFC-HE 37100).
Scale bar represents millimeters.
Fig 6.
CT-Scanned skull of the holotype (MZFC-HE 37100).
Lateral (A), dorsal (B), ventral (D), anterior (F), and posterior (G) view of the skull; lateral view of the left (C) and right (E) lower mandible. Scale bar represents millimeters.
Fig 7.
CT-Scanned skull of the paratype of Yakacoatl tlalli (UTA R-66192).
Scale bar represents millimeters.
Fig 8.
(A) Holotype of Yakacoatl tlalli (MZFC-HE 37100) with prey item.
(B) Food item consisting of a scorpion tail of the genus Diplocentrus (Alacranidae) found in the stomach of the snake. Scale bars represent centimeters.