Thor's hero shrew (Scutisorex thori ) is an extant species of shrew native to the Democratic Republic of the Congo. It and its sister species, the hero shrew (Scutisorex somereni ), are the only mammal species known to have interlocking vertebrae.
Thor's hero shrew has a smaller skull and fewer lower vertebrae—eight instead of ten or eleven—than its sister species. The vertebrae have fewer bony offshoots, and the animal's ribs are flatter and more robust. Like the hero shrew, it has an extremely strong back—roughly four times stronger than a human's, adjusted for size. It is less than 1 foot (0.30 m) long and weighs approximately 1.7 ounces (48 g). Hero shrews are generally less flexible than most mammals, but are able to turn around in confined spaces by sagittally flexing their spines.
