Donelan and his coauthors found that a kangaroo’s tail provides more forward-directed force than its hind and forelimbs combined. “Animals have discovered many uses for their tails but, as far as we ...

A 4-year-old, 2.7 kg, neutered male lop-eared Himalayan rabbit presented to a veterinarian for lethargy, inappetence, and wet, stained fur and skin on the hind limbs and abdomen (Fig. 1).

Mononykus's most distinctive feature is a pair of short, stunted forelimbs, each of which had only one functional finger and claw. The strange physiology of these short limbs has given rise to ...