Cubatyphlops, Hedges, Marion, Lipp, Marin and Vidal, 2014

Syromyatnikova, Elena, Aranda, Ernesto & González, Soraida Fiol, 2021, First insight into the diversity of snakes in the Pleistocene of Cuba, Acta Palaeontologica Polonica 66 (2), pp. 395-407 : 397-399

publication ID	https://doi.org/ 10.4202/app.00766.2020
persistent identifier	https://treatment.plazi.org/id/03D187E2-3E1B-FF8D-C399-F9D2FEC4FC9C
treatment provided by	Felipe
scientific name	Cubatyphlops
status

Treatment

cf. Cubatyphlops View in CoL

Fig. 2A View Fig .

Material.—Four precloacal vertebrae (PIN 5782/1–4), V and VII layers, late Pleistocene, El Abrón Cave, Cuba.

Description.—All vertebrae are nearly complete. They are small and dorsoventrally compressed, their centrum length ranging 1.3–2 mm ( Fig. 2A View Fig ; PIN 5782/1). In dorsal view, the interzygapophyseal constriction is moderately deep( Fig.2A View Fig 1 View Fig ). The zygosphene is widely concave anteriorly. Posteriorly, the neural arch is widely notched. The prezygapophyseal facets are oval, oriented anteriorly, but the prezygapophyseal process is long and directed almost laterally. In ventral view, the centrum lacks a haemal keel ( Fig. 2A 2 View Fig ). Subcentral foramina are present in variable size. In some specimens only one subcentral foramen is present. In lateral view, the neural arch is depressed and devoid of a neural spine ( Fig. 2A View Fig 3 View Fig ). The synapophyses have a spherical shape and are undivided. The lateral foramina are present. In anterior view, the neural canal is relatively large, having almost the same height as the cotyle ( Fig. 2A View Fig 4 View Fig ). The zygosphene is slightly convex dorsally in anterior view. The cotyle is depressed dorsoventrally. The prezygapophyses are slightly tilted upward. No paracotylar foramina are present. In posterior view, the neural canal is large and high (wider and higher than the condyle) ( Fig. 2A View Fig 5 View Fig ). The neural arch is depressed posteriorly and nearly horizontal dorsally. The condyle is depressed dorsoventrally.

Remarks.—All vertebrae display the characteristic morphological features of scolecophidian snakes: depressed neural arch devoid of neural spine, undivided synapophyses, lacking haemal keel, cotyle and condyle dorso-ventrally depressed ( Szyndlar 1991a). Most Cuban blindsnakes are assigned to the genus Cubatyphlops , which includes 12 species ( Hedges et al. 2014); consequently, we provisionally refer scolecophidians from El Abrón Cave to that genus. We realize that our fossils may actually represent other scolecophidian taxa and we hope in future excavations to use a finer-mesh screen to recover diagnostic cranial elements that may prove useful for more refined identifications.

Tropidophiidae Brongersma, 1951 View in CoL

Genus Tropidophis Bibron, 1840 View in CoL in Ramón de la Sagra 1838 –1843

Type species: Boa melanura Schlegel, 1837; Recent and Pleistocene of West Indies and N South America, île de Cuba [Greater Antilles] .

Tropidophis melanurus ( Schlegel, 1837) View in CoL

Fig. 2B View Fig .

Material.—Seven precloacal vertebrae ( PIN 5782/5–11), VI and VII layers, late Pleistocene, El Abrón Cave, Cuba.

Description.—The vertebrae are massively built, short, and wide ( Fig. 2B View Fig ; PIN 5782/5). The centrum length ranges 2.5–3.1 mm with a CL/NAW ratio of about 1. In dorsal view, the interzygapophyseal constriction is poorly developed ( Fig. 2B View Fig 1 View Fig ). The zygosphene is three-lobed with a wide central lobe. The prezygapophyseal facets are large and nearly subsquare in shape. The neural spine is swollen and flattened at the apex. The prezygapophyseal processes are short and almost invisible in dorsal view. In ventral view, the hypapophysis is long, and extends for most of the centrum length ( Fig. 2B 2 View Fig ). The subcentral foramina are small but distinct, located at the bottom of deep subcentral grooves. The subcentral ridges are well developed and almost parallel. In lateral view, the neural spine is high, but its length exceeds its height, and it presents a straight dorsal margin ( Fig. 2B View Fig 3 View Fig ). The hypapophysis is squarish in shape and markedly projects ventrally. The synapophyses are undivided, robust, and rounded. In anterior view, the zygosphene is dorsally convex ( Fig. 2B View Fig 4 View Fig ). The prezygapophyseal facets are clearly oblique. The cotyle is large and circular-shaped. The paracotylar foramina are present and positioned at the bottom of deep paracotylar grooves. In posterior view, the neural arch is depressed ( Fig. 2B View Fig 5 View Fig ). As with the cotyle, the condyle is large and circular-shaped.

Remarks.—The fossils are assigned to Tropidophis based on having vertebrae which are short and wide, with a relatively tall neural spine, depressed neural arch, reduced prezygapophyseal processes, and squarish hypapophysis Holman 2000). They agree in size and morphology with vertebrae of Recent Tropidophis melanurus ( Fig. 2C View Fig ; PIN H 103), a Cuban giant dwarf boa, and assigned here to this species. Tropidophis melanurus is the only large dwarf boa (SVL ranging 800–1000 mm), whereas other species of Tropidophis are relatively small in size, with SVL ranging 300–500 mm ( Powell and Henderson 2012).

Stratigraphic and geographic range.—Late Pleistocene until Recent of Cuba; Cuba.

Tropidophis sp.

Fig. 2D View Fig .

Material.—11 precloacal vertebrae ( PIN 5782/12–22), VI and VII layers, late Pleistocene, El Abrón Cave, Cuba.

Description.—The vertebrae are small, short and wide ( Fig. 2D View Fig ; PIN 5782/12). The centrum length does not exceed 2 mm. The ratio CL/NAW is 0.9. Their morphology is generally close to that described above for Tropidophis melanurus , however the following characters are different. The neural spine is well developed, but relatively low, about two times longer than high. It is somewhat overhanging anteriorly and posteriorly. At the apex, the neural spine is not distinctly swollen in dorsal view ( Fig. 2D View Fig 1 View Fig ). The prezygapophyseal facets are only slightly oblique in anterior view ( Fig. 2D View Fig 4 View Fig ). The cotyle and condyle are flattened dorsoventrally.

Remarks.—The vertebrae PIN 5782/12–22 are assigned to Tropidophis based on the same characters as listed for Tropidophis melanurus : short and wide vertebrae, depressed neural arch, reduced prezygapophyseal processes, and squarish hypapophysis ( Holman 2000). The described vertebrae differ from the Tropidophis melanurus described above in the smaller size and morphology of the neural spine, cotyle and condyle. The above-listed differences do not apparently relate to age or intra-columnar variability, and thus we suggest that Tropidophis sp. belongs to a separate small-sized species of Tropidophis . The vertebrae are morphologically more or less uniform, but some variations (proportions and shape of neural arch) were observed. We interpret that variation to reflect variation along the vertebral column rather than taxonomic differences. Because the osteological peculiarities of species of Tropidophis remain unknown in the literature, we tentatively consider all small-sized vertebrae of Tropidophis from El Abrón Cave as a single small form of Tropidophis sp.