Tortoise

related topics
{specie, animal, plant}
{god, call, give}
{son, year, death}
{food, make, wine}
{@card@, make, design}
{area, community, home}
{rate, high, increase}
{country, population, people}
{ship, engine, design}
{day, year, event}
{line, north, south}

Tortoises (Testudinidae) or land turtles are a family of land-dwelling reptiles of the order of Turtles (Testudines). Like their marine cousins, the sea turtles, tortoises are shielded from predators by a shell. The top part of the shell is the carapace, the underside is the plastron, and the two are connected by the bridge. The tortoise has both an endoskeleton and an exoskeleton. Tortoises can vary in size from a few centimeters to two meters. Tortoises are usually diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals.

Contents

Use of the term "tortoise"

Although the word "tortoise" is used by biologists in reference to the family Testudinidae only, in common usage it is used to describe many land-dwelling turtles. The inclusiveness of the term depends on the variety of English being used.

  • British English normally describes these reptiles as "tortoises" if they live on land.
  • American English tends to use the word "tortoise" for land-dwelling species, including members of Testudinidae, as well as other species such as box tortoises, though use of "turtle" by default is as common.
  • Australian English uses "tortoise" for terrestrial species, including semi-aquatic species that live near ponds and streams. Traditionally a "tortoise" has feet (including webbed feet) while a "turtle" has flippers.

Biology

Birth

Female tortoises dig nesting burrows in which they lay from one to thirty eggs.[1] Egg laying typically occurs at night, after which the mother tortoise covers her clutch with sand, soil, and organic material. The eggs are left unattended, and depending on the species, take from 60 to 120 days to incubate.[2] The size of the egg depends on the size of the mother and can be estimated by examining the width of the cloacal opening between the carapace and plastron. The plastron of a female tortoise often has a noticeable V-shaped notch below the tail which facilitates passing the eggs. Upon completion of the incubation period, a fully-formed hatchling uses an egg tooth to break out of its shell. It digs to the surface of the nest and begins a life of survival on its own. Hatchlings are born with an embryonic egg sac which serves as a source of nutrition for the first 3 to 7 days until they have the strength and mobility to find food. Juvenile tortoises often require a different balance of nutrients than adults, and therefore may eat foods which a more mature tortoise would not. For example, it is common that the young of a strictly herbivorous species will consume worms or insect larvae for additional protein.

Full article ▸

related documents
Salamander
Pharaoh Hound
Squirrel
Pinophyta
Bombyx mori
Ctenophore
Lovebird
Skunk
Macaw
Earless seal
Lyrebird
Prairie dog
Karyotype
Homology (biology)
Monk Parakeet
Carnivore
Hyena
Firefly
Hummingbird
Mitochondrial Eve
Hagfish
List of freshwater aquarium fish species
Mistletoe
Pelican
Scorpion
Peppered moth
Fern
Koala
Aye-aye
Herbivory