a meat-eating dromaeosaurid theropod dinosaur from the Early cretaceous of North America.
Pronunciation: die-NON-ee-kuss
Meaning: Terrible claws
Author/s: Ostrom (
1969)
Synonyms: Velociraptor antirrhopus
First Discovery: Montana, USA
Discovery Chart Position: #217
Deinonychus antirrhopus
Back in the day, Thomas Huxley announced his theory that birds had evolved from fearfully-great-lizards and was almost laughed out of science, and the opinion that dinosaurs were not-very-bright sluggish layabouts persisted right into the 1960's.
John Ostrom's study of Deinonychus—with its small body, sleek, horizontal posture, ratite-like spine, and enlarged raptorial claws on the feet, all suggestive of an active, agile predator—revolutionized the way scientists thought about dinosaurs and led to the "dinosaur renaissance".
Etymology
Deinonychus is derived from the Greek "deinos" (terrible) and "onyx" (claw), in reference to the large, sickle-shaped "killing claw" on the second toe of its hindfeet.
The
species epithet,
antirrhopus (an-TIHR-o-pus), is the Latinized Greek form of "antirrhopos" which means "counter-balancing" and refers to its tail—stiffened with interwoven tendons and bony struts—which acted as a stabiliser during running and attacking.
Discovery
The first fossils we now know belong to
Deinonychus—a partial skeleton (AMNH 3015, informally named "Daptosaurus agilis") and some large teeth wrongly associated with a smaller, partial skeleton (AMNH 3041, informally named "Megadontosaurus ferox")—were discovered near Billings, Wheatland County, Montana, in 1933 by Barnum Brown. The actual
holotype, YPM 5205, is a complete left foot and partial right foot found by John Ostrom at Edwards Ranch in the Cloverly Formation of Carbon County, Montana, during an expedition from Yale's Peabody Museum in 1964. Brown's "Megadontosaurus", minus the teeth, was renamed
Microvenator by Ostrom in 1970.
• Ostrom JH (1969) "
A new theropod dinosaur from the Lower Cretaceous of Montana".
Postilla, 128: 1–17.
• Ostrom JH (1969) "
Osteology of Deinonychus antirrhopus, an unusual theropod from the Lower Cretaceous of Montana".
Peabody Museum of Natural History, Bulletin 30: 1-165. 
• Ostrom JH (1970) "
Stratigraphy and Paleontology of the Cloverly Formation (Lower Cretaceous) of the Bighorn Basin Area,
Wyoming and Montana".
Volume 9. Fiftieth anniversary edition.
• Bakker RT (1986) "
The Dinosaur Heresies: New Theories Unlocking the Mystery of the Dinosaurs and Their Extinction".
• Chure DJ and McIntosh JS (1989) "A Bibliography of the Dinosauria: Exclusive of the Aves 1677 - 1986".
Museum of Western Colorado Paleontology Series No 1. [First official use of Brown's "Daptosaurus".
• Norell MA, Gaffney ES and Dingus L (2000) "
Discovering Dinosaurs: Evolution, Extinction, and the Lessons of Prehistory, Expanded and Updated".
• Fastovsky DE and Weishampel DB (2005) "Theropoda I: Nature Red in Tooth and Claw". In Fastovsky and Weishampel (eds.) "
The Evolution and Extinction of the Dinosaurs".
• Makovicky PJ and Grellet-Tinner G (2000) "Association between a specimen of
Deinonychus antirrhopus and theropod eggshell". In Bravo and Reyes (eds.) "First international symposium on dinosaur eggs and babies".
Isona i Conca Dellà Catalonia, Spain, 23–26 September 1999. Page 123–128.
• Grellet-Tinner G and Makovicky P (2006) "A possible egg of the dromaeosaur
Deinonychus antirrhopus: phylogenetic and biological implications".
Canadian Journal of Earth Sciences, 43(6): 705–719. DOI: 10.1139/E06-033
• Roach BT and Brinkman DL (2007) "
A Reevaluation of Cooperative Pack Hunting and Gregariousness in Deinonychus antirrhopus and Other Nonavian Theropod Dinosaurs".
Bulletin of the Peabody Museum of Natural History, 48(1): 103–138. DOI: 10.3374/0079-032X(2007)48[103:AROCPH]2.0.CO;2
• Parsons WL and Parsons KM (2009) "
Further descriptions of the osteology of Deinonychus antirrhopus (Saurischia, Theropoda)".
Bulletin of the Buffalo Society of Natural Sciences, 38
• Fowler DW, Freedman EA, Scannella JB and Kambic RE (2011) "
The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds".
PLoS One 6(12): e28964.
DOI: 10.1371/journal.pone.0028964
• Nudds JR, Lomax DR and Tennant JP (11 August 2022) "Gastroliths and
Deinonychus teeth associated with a skeleton of
Tenontosaurus from the Cloverly Formation (Lower Cretaceous), Montana, USA".
Cretaceous Research. DOI: 10.1016/j.cretres.2022.105327
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Atkinson, L.
"
DEINONYCHUS :: from DinoChecker's dinosaur archive".
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