Snakes and Lizards

Kingdom – Animalia

Phylum – Chordata
Class – Reptilia
Order – Squamata

    Squamates have:

    • a highly modified skull with the ability to open their jaws wide because their quadrate bones (back part of the jaw) can move
    • skin of horny scales or shields
    • no shells
    • males have a hemipenis (paired penes)

    Reproduction can be viviparous (live birth), ovoviviparous (live birth from an egg incubated within the female), or oviparous (egg laying). Squamates are divided into three groups:

    Sauria/Lacertilia

    Lizards

    There are approximately 5,800 species of lizard in the world, 7 of which are found in Illinois.
    Lizards:
    • have external ear openings
    • most have 4 limbs
    • most have eyelids, though some, like gekkos, have lost them
    • found on all contents except Antarctica

      Ophidia/Serpentes

      Snakes

      There are approximately 3,400 species of snake in the world, 38 of which are found in Illinois.
      Snakes:
      • lack movable eyelids.
      • lack limbs
      • lack external ear
      • are found on all continents except Antarctica
      • Ireland, Iceland, Greenland, and Hawaii have no native snakes
      • Sea snakes are found in the Indian and Pacific Oceans

      Amphisbaenia

      Worm Lizards

      There are over 180 species, none of which are found in Illinois.
      Worm Lizards:
      • lack limbs, except Bipes
      • lack external ears
      • have limited eyes
      • are fossorial (live underground)
      • have a solid bony skull to aid in digging
      • are found in North America, Europe, Africa, South America, the Middle-East and Caribbean.

      Learn more about our Amphibian and Reptile Conservation program
      Visit our Herpetology Collection website