Primer registro de cifoscoliosis en Sceloporus formosus (Squamata: Phrynosomatidae) en Veracruz, México.

A dicephalic Western Dusky Rattlesnake, Crotalus triseriatus (Squamata: Viperidae)

“…Most instances have been reported in captive individuals, whereas records of congenital malformations in wild animals tend to be rare (Bárcenas-Ibarra et al 2015). Among the congenital malformations reported in reptiles (e.g., de Carvalho et al 2017;Murphy 2018;Castillo-Juárez et al 2020) is dicephalism (or bicephalism), the duplication of part or all of the cranium and/or spinal column (Wallach 2007). A number of possible causes of dicephalism have been proposed; for snakes in nature, suggestions of possible causes include incomplete division of a single embryo, partial fusion of two embryos, abnormally low or high temperatures during incubation or gestation, regeneration after an embryonic lesion, and environmental pollution (see Wallach 2007 and references therein).…”