Hesperonychus elizabethae

Source: http://wanderingalbatross.deviantart.com/art/Fledgling-267097416

Name: Hesperonychus elizabethae

Name Meaning: Western Claw

First Described: 2009

Described By: Longrich & Currie

ClassificationDinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Dromaeosauroidea, Dromaeosauridae, Microraptoria

Hesperonychus was another small microraptorian, but rather than being from Asia this genus was found in Dinosaur Park Formation in Alberta, Canada. It lived in the Campanian age of the Late Cretaceous, about 76.5 million years ago. It is known from partial remains, and it would have been just under a meter long. It is, thus, the smallest known carnivorous dinosaur from North America (Albertonykus, though smaller, was an insectivore). The fact that this dinosaur was a microraptorian not only extends the geographic range of this group, but also the temporal range, as it lived about 45 million years after the other members of this group. It wasn’t competed with much in its environment, being one of a very few number of small carnivorous dinosaurs in the region. It was fairly common in its environment. 



Shout out goes to along-came-happiness!

The Western claw, Hesperonychus (2009)

Phylum : Chordata
Class : Reptilia
Order : Saurischia
Family : Dromaeosauridae
Genus : Hesperonychus
Species : H. elizabethae

  • Late Cretaceous (75 Ma)
  • 60 cm long and 2 kg (size)
  • Dinosaur park formation, Canada (map)

Microraptorines are well known for their small size and, in some cases, ability to fly or glide. Longrich and Currie concluded that it was unlikely for Hesperonychus to exhibit four wings or gliding behavior as in Microraptor, and speculated that it was more likely to be similar to Sinornithosaurus given their closer similarity in size. Nevertheless, Hesperonychus seems to show that microraptorines did not vary much in size, remaining very small relative to other dromaeosaurids throughout their history.

Aside from extending the known range of microraptorines, the discovery of Hesperonychus filled in a gap in the ecology of Late Cretaceous North America. Unlike roughly contemporary environments in Europe and Asia, North America appeared to lack very small carnivorous dinosaurs. In modern ecosystems dominated by endothermic mammals, small animal species outnumber larger ones. Since dinosaurs are also presumed to have been endotherms, the lack of small species and great number of known large species in North America was unusual. Hesperonychus helped to fill that gap, especially since, given the number of fragmentary remains and claws that have been collected (representing at least ten distinct specimens, compared to thirty of the contemporary Saurornitholestes and two of Dromaeosaurus), it appears to have been a very common feature of the Dinosaur Park Formation environment.

Walking with Feathers
Ken Ham posted a blog about the movie, Walking with Dinosaurs in which he quoted from an upcoming review of the movie soon to be posted on Answers in Genesis.  

The film is set in what evolutionists call the Late Cretaceous period—and the influence of evolutionary ideas is evident in the way the dinosaurs are portrayed. The Troodon, Hesperonychus, and Chirostenotes are all feathered dinosaurs that appear in the film. On many occasions Answers in Genesis has responded to the claims that dinosaurs had feathers. One of the more recent responses can be found on our website. But there’s no evidence that dinosaurs had feathers. Such claims are just the evolutionists’ way of making the evolutionary story seem true. They so want kids to believe in evolution, this claim of dinosaurs having feathers is made very often in our day—through movies, museums, books, newspaper articles, documentaries, etc.

I saw the movie today and could not help but think that there should be evidence that any member of the ceratopsian “kind” existed with the crow “kind”, elephant “kind”, bear “kind”… Just look at all the types of mammalian and avian “kinds” that were supposed to be coexisting and herding with ceratopsians. The evidence for a cretaceous crow “kind” is not there.

Two members of the family Troodontidae have been found with feathers. In fact, I’ve found a couple of articles on AiG claiming that Anchiornis huxleyi was actually a bird. If “kinds” are generally families, then why can’t other members of the Troodon “kind” have feathers or simply be considered avian “kinds” created on Day 5?

Likewise other members of the Dromaeosauridae family have been proclaimed “birds” by AiG and the evidence seems to suggest that Velociraptor might have had feathers. Why can’t other members of the Dromaesauridae family/“kind” like Hesperonychus have feathers?

At least two species of the clade Oviraptorosauria are considered “flightless birds” by AiG. Why would it be so great a leap for Chirostenotes to have feathers? Typing this out, it amazes me how many members of different dinosaur clades are considered birds by AiG.