Python sp.

Suraprasit, Kantapon, Jaeger, Jean-Jacques, Chaimanee, Yaowalak, Chavasseau, Olivier, Yamee, Chotima, Tian, Pannipa & Panha, Somsak, 2016, The Middle Pleistocene vertebrate fauna from Khok Sung (Nakhon Ratchasima, Thailand): biochronological and paleobiogeographical implications, ZooKeys 613, pp. 1-157 : 57

Taxon classification Animalia Squamata Boidae

Python sp.

Referred material.

Four trunk vertebrae-DMR-KS-05-03-00-21, DMR-KS-05-03-00-16 (two attached vertebrae), and DMR-KS-05-04-28-12.

Material description.

Vertebrae are almost complete and represent a large-sized snake (for measurements, see Tab. 17). In anterior view, the cotyle is suboval in outline with the dorsoventral compression (Fig. 35H). The ventro-lateral margins of the cotyle are nearly straight. The neural spine is well-developed and steep. The neural canal is narrow. The dorsal margin of the zygosphene is convex. The tubercle is located at the junction between the base of the zygoshene and the top of the neural canal. In posterior view, the neural arch is high and massive. The zygantra are wide and deep. In dorsal view, the median tubercle at the base of the zygosphene is distinct and the interzygapophyseal constriction is well-developed. In ventral view, the haemal keel is high (Fig. 35I) and the subcentral groove is poorly developed.

Taxonomic remarks and comparisons.

These four vertebrae are attributed to the family Boidae because of the following characters: a short, wide, and massive vertebral body (i.e., the widths of the centra are greater than the lengths, sensu Delfino et al. (2004)), a small prezygapophyseal process, paradiapophyses weakly subdivided into para- and diapophyseal surfaces, and an absence of spine-like hypapophyses on mid- and posterior-trunk vertebrae (replaced by haemal keels) ( Szyndlar and Böhme 1996, Rage 2001). Vertebrae of pythonines are commonly identified by many distinct characters: a straight and posteromedially angled zygapophyseal bridge, a triangular-shaped neural canal, a prominent zygosphenal tuberosity, a steep anterior border of the neural spine, a posterior border of the neural spine overhanging posteriorly, an absence of the paracotylar foramina, a haemal keel of mid- and posterior-trunk vertebrae delimited laterally by subcentral grooves that reach the cotylar rim, and a haemal keel projecting below the centrum (Scanlon and Markness 2001, Szyndlar and Rage 2003). The Khok Sung snake vertebrae are identified based on overall similarities with extant taxa (from the original description by Hoffstetter (1964)): a relatively elongated centrum compared to the neural arch width and the vertebral height, a longitudinal ridge along the haemal keel, and a thick zygosphenal base. The Khok Sung specimens are comparable in size to recent (e.g., Python molurus bivittatus: the specimen NMW 17117) and fossil (e.g., Python sp.: the specimens RMNH DUB 5794, DUB 6951, and DUB 6952 recovered from Trinil H. K., Java) python vertebrae. According to the fact that the species-level distinction based on the vertebral morphology is poorly known, we therefore assign these vertebrae to Python sp.