Turtles have been on the earth for more
than 200 million years. They evolved before mammals, birds, crocodiles,
snakes, and even lizards.
The earliest turtles had teeth and could
not retract their heads, but other than this, modern turtles are very
similar to their original ancestors.
Turtles live on every continent except Antarctica.
Turtles will live in almost any climate warm enough to allow them to complete their breeding cycle.
While most turtles do not tolerate
the cold well, the Blanding’s turtle has been observed swimming under
the ice in the Great Lakes region.
Turtles range in size from the 4-inch Bog Turtle to the 1500-pound Leathery Turtle.
North America contains a large variety of
turtle species, but Europe contains only two species of turtle and
three species of tortoise.
The shell of a turtle is made up of 60 different bones all connected together.
Most land tortoises have high, domed carapaces that offer protection from the snapping jaws of terrestrial predators.
Most turtle species have five toes on
each limb with a few exceptions including the American Box Turtle of the
Carolina species that only has four toes and, in some cases, only
three.
Turtles have good eyesight and an
excellent sense of smell. Hearing and sense of touch are both good and
even the shell contains nerve endings.
Some aquatic turtles can absorb oxygen
through the skin on their neck and cloacal areas allowing them to remain
submerged underwater for extended periods of time and enabling them to
hibernate underwater.
Turtles are one of the oldest and most
primitive groups of reptiles and have outlived many other species. One
can only wonder if their unique shell is responsible for their
longevity.
