Greek tortoises (Testudo graeca) are also called "Mediterranean spur-thighed" tortoises. The photos below shows you why. :0) Look at those big spurs (conical tubercles) on that male golden Greek's legs.
Greek tortoises can have one, two, or even three spurs on each back leg. Both males and females have leg spurs, and they are already present in baby tortoises. One of my adult golden Greeks has large double spurs while the others have single spurs.
In many cases, the presence or absence of these leg spurs makes it easy to distinguish between Greek (Testudo graeca) and Hermann's (Testudo hermanni) tortoises. Most Greeks have leg spurs, while most Hermann's do not. Instead, Hermann's tortoises have a terminal nail spur, a horn shaped scale, at the tip of their tails. Greek tortoises have blunt tails with no tail spurs.
However, the absence or presence of thigh spurs can not be relied upon as the only means of determining the species. Some Hermann's tortoises have thigh spurs, and some Greeks do not have spurs.
In most adult golden Greek tortoises thigh spurs are easy to see, but in some older tortoises, the spurs can be worn down flat to the skin level. It may then appear like there are no spurs present, especially if the diameter of the spurs is small.
Double spurs on the back leg of an adult male golden Greek.
Large, worn down spur on an adult female golden Greek.
In golden Greek babies, tiny leg spurs are already present at hatching.
Thigh spurs on a one-month-old golden Greek / Mesopotamian tortoise baby.
Another golden Greek hatchling. This little one is only 3 days old. Look at those tiny thigh spurs. Some golden babies are very small, only 6-10 grams. Yes, he's not much bigger than the tip of my thumb!
In addition to Greeks, some other tortoise species also have leg spurs, most notably, the sulcata aka "African spurred tortoise" (Centrochelys sulcata). Greek tortoises (Testudo graeca), commonly known as "Mediterranean spur-thighed tortoises" in Europe, stay small, but Sulcatas can grow huge (175+ lb).
Sometimes new keepers get confused with these two very different species due to both of their names having the word "spur" in it. If you are buying a baby "spur-thigh" tortoise, be sure to know which one you are getting: the small Greek tortoise or the giant sulcata.
Burmese star tortoises (Geochelone platynota) have multiple small spurs on their thighs and mature males often have a sharp spur (nail) on the tip of their tails. These tail spurs start to grow when males approach maturity. They can also drop off or wear down over time and then later on grow back.
A mature Burmese star tortoise male with a terminal tail spur. This tail spur can be short like pictured or much longer. One of my older adult males has a very long spur shaped like a hook (not pictured).
A Burmese star tortoise with multiple thigh spurs, but no tail spur.