Definitions

1. adjective

relating to or characteristic of the group of mammals, such as armadillos and anteaters, that have a secondary or supplementary articulation of the vertebrae, usually in the form of a extra bony projection

“The xenarthral mammals were well adapted to their underground environments.”

2. noun

a member of a group of mammals, such as armadillos and anteaters, that have a secondary or supplementary articulation of the vertebrae

“The xenarthral animals were found in the fossil record.”