Reptilia Taxonomy
Sean Bobbit, RVC

Introduction

Snakes are the most recently evolved group of reptiles and have numerous specialisations that distinguish them from other squamates (scaled reptiles). Their musculoskeletal system is adapted for creeping, burrowing, swimming and gliding. Chemo and thermoreceptors are a key feature in their methods of predation, in addition to extreme cranial kinesis and, in some species, deadly venoms.

Evolution and Taxonomy

Snakes are members of the class Reptilia and order Squamata (scaled reptiles). Squamata is made up of the suborders Serpentes (snakes) and Sauria (lizards). Snakes are the most recently evolved group of reptiles. Their fossil record is limited due to their fragile skeletons, however recent discoveries of early fossil snakes with posterior legs has generated debate about the origins of their evolution.

Royal python, Python regius Photo credit: Claire Porteous

Common Species

Snakes commonly presented in practice are non-venomous and come from two diverse families - Colubridae and Boidae.

Colubrids are the largest family of snakes. Common examples include milk snakes, kingsnakes, rat snakes, corn snakes and garter snakes. All are rodent eaters in captivity and oviparous except for garter snakes that eat fish and invertebrates and are viviparous.

Boids include boas and pythons. Boas are viviparous and have single, undivided subcaudal scales. Pythons are oviparous and generally have divided subcaudal scales. Common pets include boa constrictors, royal pythons (known as ball pythons in North America) and Burmese pythons.

Identification of Common Species

Identification can be difficult, given the range of species. However, these are the most common snakes you are likely to see in practice.

Family Genera
Primitive Snakes
Anomalepididae Blind snakes 4
Infraorder Typhlopidae Blind worm snakes 3
Scolecophidia Leptotyphlopidae Slender blind snakes 2
Advanced Snakes
Infraorder Acrochordidae File snakes 1
Alethinophidia Aniliidae Coral pipe snakes 1
Atractaspididae Mole vipers 1
Boidae Boas and pythons 23
Bolyeriidae Round Island ‘boas’ 2
Colubridae Advanced snakes 303
Elapidae Cobras, kraits and sea snakes 60
Loxocemidae Mexican burrowing pythons 1
Uropeltidae Short-tail snakes 10
Viperidae Vipers 28
Xenopeltidae Sunbeam snake 1