An order of mammals including the armadillos sloths and anteaters - called also Bruta The incisor teeth are rarely developed in some groups all lacking?

Here's a breakdown of the information you provided:

* Xenarthra: This order includes armadillos, sloths, and anteaters.

* Bruta: This is an older, outdated term for Xenarthra. It's not used much anymore.

* Incisor teeth: These are the front teeth used for biting and cutting. Xenarthrans rarely have well-developed incisors. In fact, some groups, like anteaters, lack incisors entirely.

The absence or reduction of incisor teeth is a key characteristic of Xenarthra, reflecting their specialized diets and lifestyles.

Let me know if you have any other questions about Xenarthrans!