Glossary
 Ginger Shorthaired Cat Revealing Paws
Shorthaired Cat

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Tetrapod
A four-footed animal.
This group includes all vertebrates  that are descendants of four-footed ancestors.
In some instances, primitive limbs of tetrapods have been modified, lost or become vestigial. Modifications include wings and fins. The limbs of snakes are vestigial.
Therefore marine mammals with fins, snakes, legless lizards, legless amphibians, and birds are categorized as tetrapods, although they are not quadrupeds.
The taxonomic superclass Tetrapoda includes over 28,000 species of amphibians, reptiles, birds and mammals.
Cf. quadruped