Calabariidae Gray, 1858

Szyndlar, Zbigniew & Georgalis, Georgios L., 2023, An illustrated atlas of the vertebral morphology of extant non-caenophidian snakes, with special emphasis on the cloacal and caudal portions of the column, Vertebrate Zoology 73, pp. 717-886 : 717

Calabariidae Gray, 1858

General information.

This group comprises only a single species, Calabaria reinhardtii , distributed in Central and Western Africa ( Wallach et al. 2014). The species was originally described by Schlegel (1848) as a species of Eryx ; however, its distinctiveness from other booids was already highlighted by Gray (1858a), who created for it, not only his new genus Calabaria , but also the new tribe Calabariina in order to accommodate this bizarre taxon. It was placed in its own monotypic (sub)family of Boidae , the Calabariinae ( Underwood 1976; Rage 1987), or in Pythonidae (Bocage 1895; Schmidt 1923; Roux-Estève 1965; Underwood 1967; Guibé 1970; McDowell 1987), or joined with “erycines” ( Kluge 1993b). Nevertheless, recent phylogenies, usually place Calabariidae within Booidea (e.g., Wiens et al. 2008; Pyron et al. 2013; Reynolds et al. 2014; Scanferla et al. 2016; Ruane and Austin 2017; Smith and Scanferla 2021; Onary et al. 2022; Zaher et al. 2023). No fossil record of calabariids exists so far.

Vertebrae of Calabariidae are indicative of the general Boa constrictor morphology, but they primarily differ on the pattern of the subcentral structures in the trunk/caudal transition (see Description and figures of Calabaria below).

The only existing figures of vertebrae of Calabariidae in the literature so far were provided by Kluge (1993b) and Frýdlová et al. (2023), both of which presented also vertebrae from the cloacal and/or caudal portion of the column. Quantitative study on the intracolumnar variability of calabariid vertebrae was conducted by Head (2021). Besides, interesting observations (without figures) on calabariid vertebral structures have been mentioned by Rage (2001), Szyndlar and Böhme (1996), and Smith (2013).