Cold-blooded, air-breathing VERTEBRATES belonging to the class Reptilia, usually covered with external scales or bony plates.

Large, long-tailed reptiles, including caimans, of the order Loricata.

Limbless REPTILES of the suborder Serpentes.

VERTEBRATES belonging to the class amphibia such as frogs, toads, newts and salamanders that live in a semiaquatic environment.

Large herbivorous tropical American lizards.

A family of snakes comprising the boas, anacondas, and pythons. They occupy a variety of habitats through the tropics and subtropics and are arboreal, aquatic or fossorial (burrowing). Some are oviparous, others ovoviviparous. Contrary to popular opinion, they do not crush the bones of their victims: their coils exert enough pressure to stop a prey's breathing, thus suffocating it. There are five subfamilies: Boinae, Bolyerinae, Erycinae, Pythoninae, and Tropidophiinae. (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, p315-320)

The capability of bearing live young (rather than eggs) in nonmammalian species. Some species of REPTILES and FISHES exhibit this.

The largest family of snakes, comprising five subfamilies: Colubrinae, Natricinae, Homalopsinae, Lycodontinae, and Xenodontinae. They show a great diversity of eating habits, some eating almost anything, others having a specialized diet. They can be oviparous, ovoviviparous, or viviparous. The majority of North American snakes are colubrines. Among the colubrids are king snakes, water moccasins, water snakes, and garter snakes. Some genera are poisonous. (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, pp321-29)

Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.

Proteins obtained from species of REPTILES.

Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.

General name for two extinct orders of reptiles from the Mesozoic era: Saurischia and Ornithischia.

Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.

A small aquatic oviparous mammal of the order Monotremata found in Australia and Tasmania.

Beliefs and practices concerned with producing desired results through supernatural forces or agents as with the manipulation of fetishes or rituals.

Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.

Animals kept by humans for companionship and enjoyment, as opposed to DOMESTIC ANIMALS such as livestock or farm animals, which are kept for economic reasons.

The capability of producing eggs (OVA) from which young are hatched outside the body. While mostly referring to nonmammalian species, this does include MAMMALS of the order MONOTREMATA.

The study of animals - their morphology, growth, distribution, classification, and behavior.

The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.

The relationships of groups of organisms as reflected by their genetic makeup.

The comparative study of animal structure with regard to homologous organs or parts. (Stedman, 25th ed)

The study of early forms of life through fossil remains.

An oviparous burrowing mammal of the order Monotremata native to Australia, Tasmania, and New Guinea. It has hair mingled with spines on the upper part of the body and is adapted for feeding on ants.

Keratins that form into a beta-pleated sheet structure. They are principle constituents of the corneous material of the carapace and plastron of turtles, the epidermis of snakes and the feathers of birds.

Historically, the treatment of disease by the administration of animal organs or their extracts (after Brown-Sequard). At present synthetic preparations substitute for the extracts of a gland. (From Stedman, 26th ed)

A board-certified specialty of VETERINARY MEDICINE, requiring at least four years of special education, training, and practice of veterinary surgery after graduation from veterinary school. In the written, oral, and practical examinations candidates may choose either large or small animal surgery. (From AVMA Directory, 43d ed, p278)

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.