Is it a flipper or a paw?

Grey seals are a species of true seal, which swim by undulating their lower bodies and hindlimbs, whereas eared seals, such as sealions, move their forelimbs in a breaststroke-like action. On land, true seals bounce along on their fronts, while eared seals walk on their four limbs.

These differences are reflected in the anatomy of the seals’ forelimbs. Those of eared seals are more flipper-like but true seals, with their clawed digits ( below), use their forelimbs to grasp and manipulate food.

Collaborating with David Hocking from Monash University and Museum Victoria, in Melbourne, Australia, Anne-Claire and Travis will compare the bone structure and musculature of the two seal groups in unprecedented detail. The result will be a better description of the movements of these limbs and how the two groups evolved in different directions from a terrestrial ancestor.