Cubophis Hedges and Vidal

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 : 399-400

publication ID	https://doi.org/ 10.4202/app.00766.2020
persistent identifier	https://treatment.plazi.org/id/03D187E2-3E1D-FF8C-C399-FCBAFEA6F912
treatment provided by	Felipe
scientific name	Cubophis Hedges and Vidal
status

Treatment

Genus Cubophis Hedges and Vidal View in CoL in Hedges et al., 2009

Type species: Coluber cantherigerus Bibron, 1840 in Ramón de la Sagra 1838 –1843; Recent and Pleistocene of Cuba, Bahamas and Cayman Islands, Cuba .

Cubophis cf. cantherigerus (Bibron, 1840 in Ramón de la Sagra 1838 –1843)

Fig. 3A, B View Fig .

Material.—16 precloacal vertebrae ( PIN 5782/66–81), V – VII layers, late Pleistocene, El Abrón Cave, Cuba.

Description.—The precloacal vertebrae have a centrum length ranging 3.8–4.7 mm ( Fig. 3A, B View Fig ; PIN 5782/66 and 5782/67). The vertebrae are longer than wide with a CL/NAW ratio of 1.4. In dorsal view, the interzygapophyseal constriction is more ( Fig. 3A View Fig 1 View Fig ) or less ( Fig. 3B View Fig 1 View Fig ) developed, sometimes shifted posteriorly. The neural spine is thin along its dorsal margin. The zygosphene is three-lobed with the central lobe poorly developed or even reduced in some large-sized specimens. In the largest specimen ( Fig. 3B View Fig 1 View Fig ) the zygosphene is apparently narrower than in smaller specimens ( Fig. 3A View Fig 1 View Fig ). The prezygapophyseal facets are usually elongate in outline, but can be nearly circular ( Fig. 3A View Fig 1 View Fig ). The prezygapophyseal processes are well developed and oriented more laterally than anteriorly. They vary in length, reaching more or less than half the length of the prezygapophyseal facets. In ventral view, the subcentral area is wide, and in some specimens ( Fig. 3B View Fig 2 View Fig ) noticeably widened anteriorly. The haemal keel is narrow anteriorly and widened posteriorly. The subcentral grooves are wide, shallow, and confined mostly to the anterior part of the centrum. The subcentral ridges are well developed. The subcentral foramina are small and located close to the haemal keel. In lateral view, the neural spine is relatively low, about twice as long as it is high. Its dorsal margin is nearly straight or slightly inclined posteriorly. The anterior margin of the neural spine is nearly vertical, whereas the posterior margin overhangs the neural arch. The haemal keel is well visible laterally. Its ventral margin can be straight ( Fig. 3A 3 View Fig ) or slightly convex ( Fig. 3B 3 View Fig ) ventrally. In the anterior part of the subcentral area, the haemal keel is low and becomes taller in its middle and posterior parts. The synapophyses have distinct parapophyseal and diapophyseal portions of similar size. The lateral foramina are present. In anterior view, the zygosphene is convex and narrow (only slightly wider than the cotyle). The cotyle is more or less dorso-ventrally flattened. The neural canal is tunnel-like and moderately large, but its dorsoventral height is lower that the dorsoventral height of the cotyle. The prezygapophyseal facets are approximately horizontal

Fig. 3B View Fig 4 View Fig ) or only slightly inclined ( Fig. 3A View Fig 4 View Fig ). Paracotylar foramina are present. In posterior view, the neural arch is distinctly vaulted. The condyle is spherical.

Remarks.—The described vertebrae are assigned to Dipsadidae based on elongated centrum, presence of haemal keel instead of hypapophysis, synapophyses clearly divided into diapophyses and parapophyses ( Holman 1979, 1981, 2000). Most West Indian snakes of the family Dipsadidae belong to the subfamily Xenodontinae and tribe Alsophiini . In Cuba, there are small ( Arrhyton ), moderate-sized ( Caraiba ), and large ( Cubophis ) species of alsophiines ( Hedges et al. 2009). The vertebrae from El Abrón Cave are relatively large and identical in morphology and size to Recent Cubophis cantherigerus ( Fig. 3C View Fig ; PIN H 104). The vertebrae described are also in greatest correspondence with those of Cubophis described and figured by Mead and Steadman (2017) in having a CL/NAW ratio within the range of 1.20–1.40, a neural spine which is twice as long as high, having a slight overhang, and a horizontally positioned prezygapophyseal facet. The differences in the length of the prezygapophyseal processes, size of zygosphene, and wideness of subcentral area in the single largest specimen PIN 5782/67 ( Fig. 3B View Fig ) may be due to developmental or individual variation, however, it is not possible to completely exclude that the largest specimen belongs to another taxon. The species of Cubophis are medium to large-sized snakes. Оnly Cubophis cantherigerus is known in Cuba ( Powell and Henderson 2012), and is nearly ubiquitous on the island ( Rodríguez-Schettino et al. 2013). For this reason, as well as the morphological similarity, we provisionally assign the described vertebrae to Cubophis cf. cantherigerus .