They travelled north during the faunal interchange, and adapted well to North America, like the ground sloths, glyptodonts, armadillos, capybaras, and other South American immigrants. Their fossils are found from Brazil to the United States, mostly in Texas and Florida.
Holmesina is a genus of pampathere, an extinct group of armadillo-like creatures that were distantly related to extant armadillos. 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 species were herbivores that grazed on coarse vegetation; armadillos are mostly insectivorous or omnivorous.
Life reconstruction of Holmesina floridanus and size comparation.
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).