Zweifel, Richard G. Department of Herpetology, American Museum of Natural History, New York, New York.
Show previous versions
- Links to Primary Literature
- Additional Readings
The superclass of the subphylum Vertebrata whose members typically possess limbs, including all forms above fishes. The members of the superclass Tetrapoda (subphylum Vertebrata, phylum Chordata) constitute the limbed vertebrates and their descendants (which may have evolved into limbless forms). The animals making up the Tetrapoda (tetrapods) stand in contrast to the fishes (the informal grouping, Pisces), whose members have fins. The tetrapods typically live part or all of their lives on land, whereas the members of the Pisces live in water. The classes of the Tetrapoda are Amphibia (frogs, toads, salamanders, and caecilians), Reptilia (snakes, lizards, turtles, and crocodiles and their kin), Aves (birds), and Mammalia (mammals). The term Tetrapoda is derived from Greek words meaning “four feet,” but there are tetrapods that have only two limbs or none at all, such as some amphibians and reptiles. These forms, however, have evolved from four-footed ancestors. Ongoing research continues to investigate the origins of tetrapods, and remarkable fossil specimens (for example, the Devonian Tiktaalik roseae) are providing new clues into the exact nature of this evolutionary process. See also: Amphibia; Animal evolution; Aves; Devonian missing link; Mammalia; Pisces (zoology); Reptilia; Tetrapod origins
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Its dedicated editorial team is led by Sagan Award winner John Rennie. Contributors include more than 9000 highly qualified scientists and 39 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 17,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information