Tortoise Shell Scutes

Scutes -- A tortoise's bony shell is covered with a layer of scutes (plates, shields, scales). These scutes do not correspond in size or shape to the bones below them. Scute attributes can be used to identify tortoises.

Carapace scutes -- A typical tortoise (land turtle) has 5 vertebrals, 4 right and left costals, 11 right and left marginals, 1 nuchal scute, and 1 supracaudal scute.

Plastron scutes -- A typical tortoise has a pair of gulars, a pair of humerals, a pair of pectorals, a pair of abdominals, a pair of femorals, and a pair of anal scutes.

Sexing -- In many tortoise species, the male has a longer tail, a concave plastron, incurved supracaudal scute, and sometimes a more angular anal notch (angle between the anal scutes). Each species has its own gender characteristics though.

Carapace (top shell)	Plastron (bottom shell)
nu - nuchal ve- vertebral co - costal ma - marginal su - supracaudal	gu - gular hu - humeral pe - pectoral ab - abdominal fe - femoral an - anal

I used the shell of an Angulate tortoise (Chersina angulata) as my model for these illustrations. Just like a typical tortoise, the Angulate tortoise carapace has 5 vertebrals, 4 pairs of costals, 10-12 right and left marginals, 1 small nuchal, and a single undivided supracaudal scute.

However, the plastron of the Angulate tortoise has a unique feature: a single, protruding gular scute (throat shield). This scute gives the species its popular name Bowsprit tortoise. Bowsprit is the long pole in the front of a sailing ship. The Angulate tortoise also has a pair of humerals, a pair of pectorals, a pair of abdominals, a pair of femorals, and a pair of anal scutes.