mammals_9
![mammals_9](https://www.elpalacio.org/wp-content/uploads/2020/02/mammals_9.jpg)
The humerus (upper arm bone) of the early Paleocene mammal Psittacotherium multifragum. The robustness of the bone and large size of the muscle attachment sites indicates that Psittacotherium was a digger. It may have burrowed in its search for roots and tubers to eat. Photograph courtesy Thomas E. Williamson.