Frogs

Kingdom – Animalia

Phylum – Chordata
Class – Amphibia
Order – Anura
Families within Illinois:
  • Hylidae
  • Ranidae
  • Bufonidae
  • Pelobatidae
  • Microhylidae

    Frogs:

    • have permeable skin
    • have permeable egg membranes
    • are constrained to moist habitats
    • have no tail as adults
    • have a urostyle – fused vertebrae
    • have elongated ankle bones
    • have elongated tarsal bones

    There are approximately 6,300 species of frog in the world, 23 of which are found in Illinois.

    Ranidae – True Frogs

      frog
    • have teeth on the upper jaw
    • Illinois species have webbed feet
    • Illinois species lay their eggs in water
    • over 600 species
    • found on all continents except Antarctica

    Hylidae – Treefrogs

    frog

  • over 900 species on Earth
  • most are arboreal
  • have claw shaped terminal phalanges (last toe bone) because of cartilage between bones
  • many have toe-pads to help climb
  • found on all continents except Antarctica

    • Pelobatidae – Spadefoot Toads

    frog
  • have teeth
  • named for keratinized “spade” on hind feet
  • found in North America, Europe, and Asia.
  • 11 known species
  • One Illinois species

    • Microhylidae – Narrow-mouthed Toads

    frog
  • most have small pointy heads
  • most lack teeth
  • only one species in Illinois
    •

    Bufonidae – Toads

      toad
    • have no teeth
    • over 350 species
    • males have a Bidder’s Organ, an undeveloped ovary
    • found naturally on every continent except Antarctica and Australia
    • introduced to Australia
        Illinois’ 2 species have:

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