Temporal range: Late Cretaceous, 70 Ma[1]
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Alvarezsauridae
Genus: BonapartenykusAgnolin et al. 2012
B. ultimus
Binomial name
Bonapartenykus ultimus
Agnolin et al. 2012

Bonapartenykus (meaning "Bonaparte's claw", named after José Bonaparte)[2] is a genus of alvarezsaurid theropod dinosaurs known from the Late Cretaceous (Campanian/Maastrichtian stage) Allen Formation of northwestern Patagonia, Argentina. The type species is B. ultimus.[3] An adult female of B. ultimus has been discovered with two eggs that may have still been inside its oviducts,[1][2] although some evidence suggests that the eggs may have been incubated in a nest.[4] The size of the adult female has been estimated as at least 8.5 feet (2.6 m),[5][2] and the weight of Bonapartenykus has been estimated as 100 pounds (45 kg).[1] Its diet probably consisted of insects.[1] Paleontologist Fernando Novas compared its bones to those of the ñandú, a modern-day Patagonian flightless bird.[6]

The eggs of Bonapartenykus were considered unique enough for them to be given a new parataxonomic name, Arriagadoolithus, which was classified in a new oofamily, the Arriagadoolithidae, so named for the owner of the site where the discovery was made.[3][4]


  1. ^ a b c d Bob Strauss. "Bonapartenykus". The New York Times Company. Retrieved April 19, 2012.
  2. ^ a b c Jennifer Viegas (April 11, 2012). "Dinosaur Mom Died with Eggs Still Inside Her". Discovery News. Discovery Communications. Retrieved April 19, 2012.
  3. ^ a b Federico L. Agnolin; Jaime E. Powell; Fernando E. Novas & Martin Kundrát (June 2012). "New alvarezsaurid (Dinosauria, Theropoda) from uppermost Cretaceous of north-western Patagonia with associated eggs". Cretaceous Research. 35: 33–56. doi:10.1016/j.cretres.2011.11.014.
  4. ^ a b Nola Doyle-Burr (April 11, 2012). "Which came last, the dinosaur or the egg?". The Christian Science Monitor. Retrieved April 19, 2012.
  5. ^ Holtz, Thomas R., Jr.; Rey, Luis V. (2007). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages ([1]). New York: Random House. ISBN 978-0-375-82419-7.
  6. ^ "Bird-like dinosaur found with eggs in Patagonia". BBC News. BBC. April 12, 2012. Retrieved April 19, 2012.