Named By: Federico L. Agnolin, Jaime E. Powell, Fernando E. Novas and Martin Kundrát - 2012.
Classification: Chordata, Reptilia, Dinosauria, Saurischia, Theropoda, Coelurosauria, Maniraptoriformes, Alvarezsauroidea, Alvarezsauridae, Patagonykinae.
Species: B. ultimus (type).
Diet: Presumed insectivore.
Size: Estimated at 2.6 meters long.
Known locations: Argentina, Patagonia.
Time period: Late Campanian/Early Maastrichtian of the Cretaceous.
Fossil representation: Partial post cranial skeleton with two eggs. Additional egg remains found in close proximity to the type specimen.
is a hot bed for dinosaur fossils, although it’s usually the
dramatic giants such as Giganotosaurus
take the spotlight. Bonapartenykus was much
smaller than these two
dinosaurs, however for the purposes of palaeontology and
understanding of Mesozoic Patagonia it is at least just as important.
First is the dating if the type specimen to near the boundary of the
Campanian and Maastrichtian stages. This indicates that while related
forms like Patagonykus
are only known from earlier in the Cretaceous,
patagonykine alvarezsaurs survived in South America until the latest
stage of the Cretaceous. It is this relationship to Patagonykus
other alvarezsaurs in general that has led palaeontologists to consider
Bonapartenykus an insectivore despite the lack of a
skull in the type
The Bonapartenykus type specimen is thought to have been a female due to the presence of two eggs that are preserved in the area where the oviducts are expected to have been. On top of this is the presence of further egg remains that were found near to the type specimen that may have been part of a nest belonging to this dinosaur. Another interesting fact about the eggs is that they show the signs of fungal contamination. It’s possible that the death of the mother meant that the nest could not be tended which allowed the fungus to take hold. Because the eggs of Bonapartenykus were unlike any other dinosaur egg so far seen they have been placed in their own family, the Arraigadoolithidae.
Bonapartenykus is named after the palaeontologist José F. Bonaparte who is considered one of the most important figures in Argentine palaeontology and is credited with naming the dinosaurs Carnotaurus, Agustinia and Saltasaurus as well as the specialised pterosaur Pterodaustro amongst a great many others.