Aardvark Forelimb and Scapula
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Aardvarks scratch-dig by alternatively flexing and extending their limbs. The claws break and loosen the soil which is then thrown under the body and dispersed by the hind legs to the rear of the animal. Other mammals that use this method to excavate include armadillos, pangolins, ground squirrels and carnivores. The clavicle is well developed.  |
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The humerus, radius and ulna are relatively short and stout which enables the aardvark to apply great force against the substrate. The radius is also shorter than the humerus which is line with the rule that the distal elements of the limb tend to be short in fossorial animals. The metacarpals of the manus are not markedly shorter than the radius which is the case in the more specialised diggers like echidnas and moles. Nor are the metacarpals very elongate as in the ungulates. Aardvarks walk on their digits and thus have digitigrade locomotion. The nails are actually somewhere between true nail and hoof in form. They are strongly constructed, shovel-like, and obviously adapted for digging. They are also used for defense. The first digit is missing in the forelimb and the third digit has the longest claw. |
