Deinonychus fossil map
Where fossils of Deinonychus have been found, shown on the Earth as it looked about 100 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 100 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Theropods |
|---|---|
| Lived | 143.1–93.9 million years ago (Berriasian to Cenomanian) |
| Periods | Cretaceous |
| Family | Dromaeosauridae |
| Named by | Ostrom 1969 |
| Fossil records | 47 occurrences at 35 locations (PBDB) |
| Found in | United States, Brazil |
| Rock formations | Cloverly, Antlers, Cedar Mountain, Sousa, Holly Creek, Arundel Clay |
About Deinonychus
Deinonychus ( dy-NON-ih-kəs; from Ancient Greek δεινός (deinós) 'terrible' and ὄνυξ (ónux), genitive ὄνυχος (ónukhos) 'claw') is a genus of dromaeosaurid theropod dinosaur with one described species, Deinonychus antirrhopus. This species, which could grow up to 3.4 meters (11 ft) long, lived during the Early and Late Cretaceous Period, about 115–98 million years ago (from the mid-Aptian to Cenomanian stages). Fossils have been recovered from the U.S. states of Montana, Utah, Wyoming, and Oklahoma, in rocks of the Cloverly Formation and Antlers Formation, though teeth that may belong to Deinonychus have been found much farther east in Maryland.
Paleontologist John Ostrom's study of Deinonychus in the late 1960s revolutionized the way scientists thought about dinosaurs, leading to the "dinosaur renaissance" and igniting the debate on whether dinosaurs were warm-blooded or cold-blooded. Before this, the popular conception of dinosaurs had been one of plodding, reptilian giants. Ostrom noted the small body, sleek, horizontal posture, ratite-like spine, and especially the enlarged raptorial claws on the feet, which suggested an active, agile predator.
Text in “About” is quoted from the Wikipedia article Deinonychus (revision 1379922637), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 22 October 2026. Ages are those of the rock layers the fossils were found in. Wikidata: Q14405.
