An illustrated atlas of the vertebral morphology of extant non-caenophidian snakes, with special emphasis on the cloacal and caudal portions of the column Author Szyndlar, Zbigniew Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Slawkowska 17, 31 - 016 Krakow, Poland Author Georgalis, Georgios L. https://orcid.org/0000-0001-7759-6146 Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Slawkowska 17, 31 - 016 Krakow, Poland dimetrodon82@gmail.com text Vertebrate Zoology 2023 2023-09-27 73 717 886 http://dx.doi.org/10.3897/vz.73.e101372 journal article http://dx.doi.org/10.3897/vz.73.e101372 2625-8498-73-717 8F3D5EDA2F184E5CA53E2F7741FF1339 318B657A15AB5708B3C35FC1A82B4945 Aspidites Peters, 1877 Material examined. Aspidites melanocephalus (Krefft, 1864) (NHMUK 1946.1.8.2 [part of the holotype ]; QM J30786 ; UMMZ 190743) . Description (Figs 152-157). Trunk vertebrae . Centrum much shorter than wide; cotyle and condyle orbicular; neural arch vaulted; posterior median notch of the neural arch deep; neural spine higher than long in most trunk vertebrae; prezygapophyseal accessory processes vestigial; hypapophyses restricted to about the first 70 vertebrae; haemal keel moderately developed, ridge-like (more anterior vertebrae) to flattened (more posterior vertebrae); paracotylar foramina absent. Figure 152. Pythonidae : Aspidites melanocephalus (QM J30786), anterior trunk vertebrae. Figure 153. Pythonidae : Aspidites melanocephalus (QM J30786), trunk vertebrae. Figure 154. Pythonidae : Aspidites melanocephalus (QM J30786), posteriormost trunk and cloacal vertebrae. Figure 155. Pythonidae : Aspidites melanocephalus (QM J30786), cloacal and caudal vertebrae. Figure 156. Pythonidae : Aspidites melanocephalus (NHMUK 1946.1.8.2 [part of the holotype]), mid-trunk vertebra. Figure 157. Pythonidae : Aspidites melanocephalus (UMMZ 190743), anterior trunk vertebrae. Trunk / caudal transition . The last trunk and cloacal vertebrae provided with a bulb-like haemal keel, disappearing in the anteriormost caudal vertebrae. Paired haemapophyses appear on the third caudal vertebra. Shape and length of haemapophyses in lateral view vary across the succeeding vertebrae: they are smaller in their first appearance, they get larger in C 6, possessing also a distinct anteroventral projection, and they get longer towards V 20. Posteriormost caudal vertebrae are fused. Number of vertebrae . Aspidites melanocephalus (QM J30786): 363 (307+5+51). Data from literature (all for Aspidites melanocephalus ): 337 trunk vertebrae plus 5 cloacal vertebrae plus 52 caudal vertebrae ( Scanlon 1993 ); 385 vertebrae in total ( Parmley and Reed 2003 ); 293 trunk and cloacal vertebrae plus 48+ caudal vertebrae ( Alexander and Gans 1966 ).