Nothronychus, meaning “slothful claw”, is a genus of dinosaur from the mid-Turonian age of the Late Cretaceous Period (91 million years ago). It was discovered in the Moreno Hill Formation in the Zuni Basin, on the border of New Mexico and Arizona. The type species, N. mckinleyi, was described in 2001. A second species, N. graffami, was discovered in the Tropic Shale Formation of Utah. This specimen dated back about a million years before the nominate species.
Nothronychus had a toothless beak, bird like hips, and four toes on each foot, with the toes all facing forward. Although Nothronychus belonged to a group of dinosaurs that was carnivorous, it evolved to become more omnivorous, and mostly subsisted on a diet of plants. It was bipedal and walked more upright than its carnivore ancestors. An adult would have been 15 to 20 feet long, 10 to 12 feet tall, and weighed about 2,000 pounds. The teeth were leaf-shaped with circular roots. It had a long neck and long arms. It had well-skilled hands with 4 inch curved claws on the fingers. It had short hind legs and a short tail. The abdomen was “pot-bellied”.
The second found species, N. graffami, was named for Graffam, the discoverer of the original specimen, N. mckinleyi.