Like armadillos, and unlike the other extinct branch of megafaunal cingulates, the glyptodonts, the shell was made up of flexible plates which allowed the animal to move more easily.

Holmesina individuals were much larger than any modern armadillo: They could reach a length of 2 metres (6.6 ft), and a weight of 227 kilograms (500 lb), while the modern giant armadillo does not attain more than 54 kilograms (119 lb).

[3] Their fossils are found from Brazil to the United States,[4] mostly in Texas and Florida.

Holmesina species were herbivores that grazed on coarse vegetation; armadillos are mostly insectivorous or omnivorous.

[6] Three H. cryptae specimens have been described bearing evidence of bacterial and fungal infections, along with sand flea ectoparasitism.