Pronunciation: hes-puh-ruh-NIE-kus
Meaning: West claw
Author/s: Longrich and Currie (2009)
Synonyms: None known
First Discovery: Alberta, Canada
Discovery Chart Position: #670
Hesperonychus elizabethae
Collected by the late Dr. Elizabeth Nicholls way back in 1982, Hesperonychus lay misidentified for 25 years until Nicholas Longrich "discovered" its remains whilst sifting through drawers at the University of Alberta in 2007.
Known only from pelvic bones from Dinosaur Provincial Park which were fused and therefore belonged to an adult for sure, and a few toes bones from the same area that were referred to it tentatively, Hesperonychus may also own at least some of the copious sharp pointy bits in the Royal Tyrrell Museum collections that have been collected from the same general area over the years, such as raptor-like "killing claws" and steak-knife-esque killing teeth to match. If so, Hesperonychus was well-equipped to terrorize the inhabitants of Late Campanian Albertan swamps and forests, but its awesome arsenal was all wrapped up in a body about the size of a squirrel. Yes, a squirrel.
As an area not only dominated by large-bodied predators (such as tyrannosaurs) but previously lacking evidence of a small meat-eating dinosaur altogether, palaeontologists were beginning to wonder if the "tiny terror" niche of Late Cretaceous North America was occupied by mammals, and if small hunters of the theropod persuasion — that is: under 10kg in weight — were unique to Asia. Hesperonychus blew that theory out of the water in spectacular fashion, and in doing so expanded the fossil range of microraptorian dinosaurs, dragging it forward by some 45 million years. But, funnily enough, it is most closely related to the tiny, feathered critters Sinornithosaurus and Microraptor, which are both Asian, hailing from the Jehol Group of China.
Known only from pelvic bones from Dinosaur Provincial Park which were fused and therefore belonged to an adult for sure, and a few toes bones from the same area that were referred to it tentatively, Hesperonychus may also own at least some of the copious sharp pointy bits in the Royal Tyrrell Museum collections that have been collected from the same general area over the years, such as raptor-like "killing claws" and steak-knife-esque killing teeth to match. If so, Hesperonychus was well-equipped to terrorize the inhabitants of Late Campanian Albertan swamps and forests, but its awesome arsenal was all wrapped up in a body about the size of a squirrel. Yes, a squirrel.
As an area not only dominated by large-bodied predators (such as tyrannosaurs) but previously lacking evidence of a small meat-eating dinosaur altogether, palaeontologists were beginning to wonder if the "tiny terror" niche of Late Cretaceous North America was occupied by mammals, and if small hunters of the theropod persuasion — that is: under 10kg in weight — were unique to Asia. Hesperonychus blew that theory out of the water in spectacular fashion, and in doing so expanded the fossil range of microraptorian dinosaurs, dragging it forward by some 45 million years. But, funnily enough, it is most closely related to the tiny, feathered critters Sinornithosaurus and Microraptor, which are both Asian, hailing from the Jehol Group of China.
(Elizabeth Nicholl's West Claw)Etymology
The species epithet, elizabethae, is named in honor of Elizabeth (Betsy) Nicholls, the well-known Alberta palaeontologist and former curator at the Royal Tyrrell Museum in Drumheller who unearthed the fossils.
Discovery
Hesperonychus was discovered at the Dinosaur Park Formation on the south side of the Red Deer River, 20 km east of Dinosaur Provincial Park, Alberta, Canada, by Elizabeth Nicholls in 1982.
The holotype (UALVP 48778, housed at the University of Alberta's Laboratory for Vertebrate Palaeontology) consists of pelvic bones. In addition, numerous claws and foot bones have been recovered from the Dinosaur Park and Oldman Formations and tentatively referred to Hesperonychus, so the name may be based on remains that don't actually belong to it. It wouldn't be the first time.
Preparator
Clive Coy.
