The identification key to the snapping turtle family, given by
Dr. Pritchard in his " Encyclopedia of turtles ":
KEY TO CHELYDRIDAE
- Supramarginal scutes present; eyes on the side of head; a worm - like fishing lure
on the base of mouth --------------> Macroclemys - alligator snapper
- Supramarginal scutes absent; eyes inclined toward top of head; no lure
on floor of mouth -----------------> Chelydra - common snapper
With its primitive looks, the snapping turtle is easily recognizable.
The carapace has three pronounced ridges, that almost disappear with age, and ranges from black,
brown, tan to olive in color.
Plastron , greatly reduced in snapping turtles, usually yellowish ( with occasional
dark patterns on some individuals ) throughout the turtles life.
The skin , covered with tubercles and scales of different sizes, can be black, grey,
brown, tan, olive or yellow, but usually a combination of these colors ( tends to be much
brighter on the underside ).
The head is large, with strong jaws and dorsolaterally positioned eyes.
Jaws are usually yellow
or cream with dark lines on them, and there is a pair of barbels on the chin.
Eyes have a black pattern of spots that resemble a cross in most snappers, and can be viewed
The neck is long, thick, and covered with many tubercules on top and sides. While "snapping",
a snapping turtle can reach with its beak back as far as half the length of its carapace.
The legs are very strong, large, heavily scaled and webbed.
Snapper's long neck
The windpipe in snapper's mouth - a canal through which the turtle can exhale air.
The snapper's body seems to be "too small" for its shell, and the turtle can not completely
The tail, as long or longer than the carapace, has three raws of scales on it.The center one
, very pronounced in some individuals, contributes to the snapping turtles' resemblance to the dinosaurs.
In the eyes of many keepers, those looks make the snapping turtle a very
attractive species, giving a feeling of coming across a living fossil, snapping turtle -
the modern age dinosaur.
In description, generalizing,
the Chelydra s. osceola resembles Chelydra s. rosignoni ,
and Chelydra s. serpentina resembles Chelydra s. acutirostris.
Comparing the Ch. s. osceola ( the Florida snapper )
with Ch. s. serpentina ( the common snapper )
, the neck muscles of
the Florida snapper are stronger. As a result, more space is needed
when withdrawing its
head, so there is more space across the free ribs
and the carapace is deeper ( slopes sharply at the back )
The evidence of this would be the comparison of the ratio width of the 3rd central costal scutes to
the height of the 2nd. For the Florida snapper it's height is on average, 0.838 ,
and for the common snapper is 0.973.( Pritchard, Encyclopedia of turtles ).
The Florida snapper has granular scales on top of the head and the papillae on the neck and soft under
parts of the face are pointed, while in the common snappers the scales are fewer in number and flat
, and the papillae rounded.
Florida snapping turtle (left) and common snapper (right)
Also, the snout of the Florida snapping turtle is more pointed than that of the common snapper.
The females and males of snapping turtles are about the same size.
The difference between sexes shows mainly in the structure of the tail,
and for the male snapper the tail is longer, thicker ( 2 ), and the vent is located much further ( 1 ) from the edge of
the plastron then that of the female.
Also, the plastron in males is somewhat smaller ( 3 )
and the bridges connecting the plastron and carapace
are narrower, which presumably helps males to hold on
to the females carapace during copulation.
The photograph below shows the underside tail area of
a male and a female Mexican snapping turtle - Chelydra rossignoni. Please pay
attention to the marked differences between the two.
Sometimes, for an untrained eye the alligator snapping turtle is mistaken for a common snapper, and the other way around ( it is in fact difficult to identify a turtle species looking from a distance at an animal in murky water, possibly covered with large amounts of green moss-like algae on their backs ).
Both species belong to the same family, yet their shells and bodies are quite different. The main difference, not easy to discover unless the animal opens its jaws, is the presence of a fleshy pink worm-like body at the bottom of the alligator snapping turtle's mouth.
I have seen quite a few pages on the Net mixing up the two species, mostly with the common snapper being given the description of an alligator snapper ( sometimes the text and pictures don't match ).
As a result of this, some estimations of a turtle's age or size might not be correct at times. In many areas the terms " snapping turtle " or " snapper " mean and are identified with the alligator snapping turtle only.
What might be true for the alligator snapping turtles may not be true for the common snappers, and vice versa.
The alligator snappers grow much much larger than the common snappers and live much longer lives. Considering their slow pace of growing to very large sizes, around 200 lb., their age probably exceeds 100 years.