CONICET, Buenos Aires, Argentina

Bizarre tail weaponry in a transitional ankylosaur from subantarctic Chile

Published in Nature

Stegouros elengassen, an ankylosaur from the late Cretaceous of Chile, has a large tail weapon, named a macuahuitl after the Aztec club, with a frond-like structure formed by seven pairs of laterally projecting osteoderms encasing the distal half of the tail.