Photo: Wyoming Dinosaur Center, via Wikimedia Commons
- Order
- Chiroptera
- Family
- Icaronycteridae
A Fossil Lake bat more closely related to modern bats than O. finneyi, with early echolocation.
Ear morphology suggests this species had developed the use of echolocation. It lacks claws on its wing digits, except for one claw on the index finger and one on the thumb.
One specimen has been discovered with a small fish scale preserved in the stomach, suggesting I. index fed on both insects and fish. The family Icaronycteridae appears to have gone extinct during the middle Eocene.
Species text: National Park Service, Fossil Butte National Monument — Fossil Mammal Species.