A reptile in your home
Reptiles are air-breathing and generally cold blooded. Their skin is invariably covered in scales or scutes and they lay eggs whose embryos are surrounded by the amnion membrane.
Apart from the Antarctica, there are four living types of reptiles which inhabit all other continents.
Four groups of reptiles
The four recognised groups of reptiles include Crocodilia (crocodiles, gavials, caimans and alligators) and total 23 species; Sphenodontia (tuatara) - two species; Squamata (lizards, snakes and worm-lizards) - around 7,900 species; and Testudines (turtles and tortoises) totalling around 300 species.
Obviously many of these are not suitable for home pets! But there are many reptiles that people do keep as pets.
A bit about reptiles
Most species of reptiles are oviparous which means they are egg laying creatures. However, certain species of squamates are capable of giving birth to live babies. This is achieved in one of two ways: either through ovoviviparity which is egg retention, or viviparity where the babies are born without the use of calcified eggs.
Many of the viviparous species feed their foetuses through varying forms of placenta analogous.
Reptiles range in size from a tiny gecko to the saltwater crocodile that can grow to up to 6m and can weigh in at more than 1000kgs.
