a small grouping of huge extinct herbivorous mammals typical when you look at the Tertiary formation for the usa
- several huge, extinct, herbivorous animals, common inside Tertiary development of the US.
(n. pl.) A group of huge, extinct, herbivorous animals, typical into the Tertiary development associated with the United States.
Although the brain is relatively larger, the bones of the limbs, especially the short, five-toed feet, approximate to those of the Amblypoda and Proboscidea; but in the articulation of the astragalus with both the navicular and cuboid Arsinoitherium is nearer the former than the latter group. It is probable, however, that these resemblances are mainly due to parallelism in development, and are in all three cases adaptations necessary to support the enormous weight of the body.