5 days ago · A reptile is any member of the class Reptilia, the group of air-breathing vertebrates that have internal fertilization, amniotic development, and epidermal scales covering part or all of their body. The major groups of living reptiles are turtles, tuatara, lizards, snakes, and crocodiles.

A reptile is an air-breathing animal that has scales instead of hair or feathers. Reptiles have lived on Earth for more than 280 million years. Scientists consider them to be the ancestors of birds and mammals. Over the years many kinds of reptiles have become extinct, or died out.

reptile, Any of the approximately 8,700 species of the class Reptilia, the group of air-breathing vertebrates that have internal fertilization and a scaly body and are cold-blooded. Most species have short legs (or none) and long tails, and most lay eggs.

Encyclopædia Britannica, Inc. As the term vertebrate implies, reptiles have a backbone. The internal organs of reptiles are similar to those of birds and mammals. No reptile has gills; all rely on well-developed lungs for respiration.

Mar 31, 2025 · turtle, (order Testudines), any reptile with a body encased in a bony shell, including tortoises. Although numerous animals, from invertebrates to mammals, have evolved shells, none has an architecture like that of turtles. The turtle shell has a top (carapace) and a bottom (plastron).

6 days ago · lizard, (suborder Sauria), any of more than 5,500 species of reptiles belonging in the order Squamata (which also includes snakes, suborder Serpentes). Lizards are scaly-skinned reptiles that are usually distinguished from snakes by the possession of legs, movable eyelids, and external ear openings.

5 days ago · Reptile - Circulation, Respiration, Adaptations: Modern reptiles do not have the capacity for the rapid sustained activity found in birds and mammals. With the evolution of lungs in early tetrapods, a new and more efficient circulatory system evolved.

5 days ago · Reptile - Evolution, Paleontology, Adaptation: The first land vertebrates, the Tetrapoda, appeared near the middle of the Devonian Period. The earliest known reptiles, Hylonomus and Paleothyris, date from the Late Carboniferous. The Mesozoic Era is known as the “Age of Reptiles.”

A turtle is a reptile that has a shell covering its body. Turtles are known for moving very slowly. There are more than 350 species, or types, of turtle. Turtles are found in most parts of the world. Most live in freshwater ponds, lakes, or rivers. Others live in the ocean or on land. Some turtles live in forests or even in the desert.

2 days ago · snake, (suborderSerpentes), any of more than 3,400 species of reptiles distinguished by their limbless condition and greatly elongated body and tail. Classified with lizards in the order Squamata, snakes represent a lizard that, over the course of evolution, has undergone structural reduction, simplification, and loss as well as specialization.