Differentiating Indotestudo forsteni from Indotestudo elongata

It is often said that Indotestudo elongata can be differentiated from Indotestudo forsteni via the presence of a nuchal scute.  Unfortunately, it is not that easy as some Indotestudo forsteni actually have a nuchal. 

It has also been said that the difference between the two species is obvious via the differences in the markings of the plastron and carapace.   Again, I have seen animals that could be easily mistaken simply by looking at the markings (especially I. elongata that look like I. forsteni in terms of their patterns). 

Below is a pictorial summary of the methods I use to differentiate the two species.

The Nuchal Scute

If your Indotestudo has a nuchal scute...it could be either I. elongata or I. forsteni. 

For example, the above animal has a pronounced, rather wide nuchal.

The animal above also has a nuchal scute but is a different species (top picture is I. elongata, picture above is an I. forsteni).

However, if there is no nuchal scute, such as in the picture above, then you can be reasonably sure you have a forsteni (odds of the animal being an I. travancorica, a highly protected Indian species which also lacks a nuchal scute, are extremely, extremely slim).

The Interpectoral Seam

This anatomical feature in my opinion is the best way to differentiate the two.  The interpectoral seam is the two scutes that run between the front limbs on the plastron.  In I. elongata, this seam is very wide from the front of the animal to the back of the animal (see picture of I. elongata just below with the interpectoral scutes denoted by the red bars):

In I. forsteni, the interpectoral seam is very short from the front to the back (see the picture of an I. forsteni below again with the red Ts denoting the interpectoral seam) :

If the above is insufficient for you to identify your Indotestudo, please feel free to send a digital picture of your animal to ctabaka@memphiszoo.org or rednine@earthlink.net for assistance.