First insight into the diversity of snakes in the Pleistocene of Cuba

Abstract

The herpetofaunal biodiversity of West Indies suffered a significant change during the last few million years that is well documented for some squamate reptilies (lizards). However, almost nothing is known about past biodiversity of snakes, which are active predators and important component of terrestrial ecosystems. Here we describe the fossil remains of snakes (Reptilia: Serpentes) from the late Pleistocene of El Abrón Cave, Cuba. This is the first representative assemblage of fossil snakes from Cuba. It allows us to evaluate the taxonomic diversity of snakes in the Pleistocene of the island for the first time. The material includes eight taxa from the four snake families: cf. Cubatyphlops (Typhlopidae), Tropidophis melanurus, Tropidophis sp., Cubophis cf. cantherigerus, Arrhyton sp., cf. Caraiba andreae, Dipsadidae indet., and Natricidae indet. (Natricidae). Two (Dipsadidae indet. and Natricidae indet.) are not known in the modern fauna of Cuba. The assemblage from El Abrón Cave shows that ophidian Pleistocene assemblage was different from modern snake fauna of Cuba and was probably more diverse at genus level than it is now. Most of taxa revealed in El Abrón Cave were not previously known in the fossil record.

Westernmost record of the Spotted Red Trope, Tropidophis maculatus (Squamata: Tropidophiidae), with comments on the Tropidophis species assemblage from the Guanahacabibes Peninsula

“…Consequently, three basic ecotypes (terrestrial, semi-arboreal, and generalist) exist in most habitats, although a fourth gracile and climbing variant of the semi-arboreal ecotype, always represented by the Broad-banded Trope (T. feicki), occurs in mesic forested areas with limestone cliffs in western and central Cuba (Rodríguez-Cabrera et al 2020a, 2020b; see also Hedges and Garrido 1992 and Díaz and Cádiz 2020 for previous references to arboreality in the genus). Syromyatnikova et al (2021) found the first fossil evidence for the occurrence of multispecies Tropidophis assemblages at least since the Pleistocene (2.59-0.01 MYA) from cave deposits in western Cuba, where vertebrae of both the Giant Trope (T. melanurus), the almost omnipresent trope species in Cuban ecosystems, and of a second smaller unidentified species were present. The fact that regions where representatives of only some of the ecotypes be extirpated or extinct, have not yet dispersed to those areas, or have yet to be discovered.…”

Achieving kinematic identity across shape diversity in musculoskeletal modeling

“…Vertebrae can be assigned to Dipsadidae through a combination of characters that individually are not necessarily exclusive to the group. Dipsadid snakes generally have vertebrae that are square to slightly longer than wide in dorsal view, an elongated centrum, and long, low, and narrow neural spines that overhang posteriorly (some taxa also overhang anteriorly) (Holman, 2000;Parmley and Hunter, 2010;Holman et al, 2011;Mead and Steadman, 2017;Jurestovsky, 2021;Syromyatnikova et al, 2021). The neural arch is depressed to moderately vaulted in different species, and the zygosphene is usually crenate, but can be concave in some species when viewed dorsally (Holman, 2000;Mead and Steadman, 2017).…”

“…The cotyle and condyle are round to slightly dorsoventrally compressed, where the cotyle is flattened on the ventral portion in anterior view (Mead and Steadman, 2017;Jurestovsky, 2021) Epizygapophyseal spines are absent (Holman, 2000;Mead and Steadman, 2017;Jurestovsky, 2021). The synapophyses are divided into distinct diapophyses and parapophyses (Holman, 2000;Syromyatnikova et al, 2021). Distinct hemal keels with adjacent subcentral ridges are present, and hypapophyses are absent from trunk vertebrae except potentially in a few species (Holman, 2000;Ikeda, 2007;Head et al, 2016;Mead and Steadman, 2017;Syromyatnikova et al, 2021) Remarks.…”

“…The synapophyses are divided into distinct diapophyses and parapophyses (Holman, 2000;Syromyatnikova et al, 2021). Distinct hemal keels with adjacent subcentral ridges are present, and hypapophyses are absent from trunk vertebrae except potentially in a few species (Holman, 2000;Ikeda, 2007;Head et al, 2016;Mead and Steadman, 2017;Syromyatnikova et al, 2021) Remarks. The vertebrae of many extant dipsadid snakes have not yet been described and is outside the scope of this study, making it difficult to confirm the above characters across the entire group.…”

Giant dwarfs: Very large giant tropes Tropidophis melanurus (Squamata: Tropidophiidae), and new maximum size records for the species

“…The occurrence of these assemblages appears to reflect morphological and behavioral differentiation that allows ecological segregation (Rodríguez-Cabrera et al 2020a). Based on fossil remains of T. melanurus and a second smaller congener from a cave deposit in western Cuba,Syromyatnikova et al (2021) found evidence for the occurrence of Tropidophis assemblages at least since the Pleistocene (2.59-0.01 MYA).…”