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Pelobatidae are the European and American Spadefoot Toads. The content of the family as used here is more restricted than many others use it. The Asian megophryines and pelodytines were recognized as full families, Megophryidae and Pelodytidae, by Cannatella (1985).
Living pelobatids are rotund with short limbs and large eyes with vertical pupils. However, it is possible (but not yet demonstrated) that the morphology of the living forms is convergent, because some fossil pelobatids of the genus Eopelobates are rather gracile, lightly-built animals. In order to burrow, spadefoot toads use the spade, a bony element of the hindfoot capped with a keratinous cover. They do so rear-first into the ground (most burrowing frogs do so rear-first, only a very few such as Hemisus, enter the ground head-first).
The North American species have been placed in either one genus (Scaphiopus) or two (Spea, for the smaller species). Each group is monophyletic, so the division is somewhat arbitrary. However, the two groups are different in morphology and ecology, so recognition of two genera emphasizes the distinctiveness of each.
Pelobates are also well known as fossils from as far back as the Eocene and extend to the present. Scaphiopus is known from the early Oligocene. Macropelobates is from the Middle Oligocene.