What are the two main orders of amphibian and tell how to distinguish between them?
Order Anura (frogs and toads)
Adult frogs and toads are characterized by long hind legs, a
short body, webbed digits, protruding eyes and the absence of a
tail. Most have a semi-aquatic lifestyle, but move easily on land
by jumping or climbing. They typically lay their eggs in puddles,
ponds or lakes; and their larvae, called tadpoles, have gills and
develop in water.
Order Caudata (newts and salamanders)
Cuadata have slender bodies, short legs, and long tails. The
moist skin of the amphibians fits them to habitats either near
water or under some protection on moist ground, usually in a
forest. Some species are aquatic throughout life, some take to the
water intermittently, and some are entirely terrestrial as adults.
Salamanders superficially resemble lizards, but are easily
distinguished by their lack of scales. They are capable of
regenerating lost limbs.