Dakotaraptor: Beast of the Week

This week we will be revisiting an unfortunately very confusing dinosaur.  Let's check out Dakotaraptor steini.  Dakotaraptor was originally published on in 2015 and was claimed by the head author to be a very large dromaeosaur, in the same family as Deinonychus and Velociraptor.  It would have lived in what is now South Dakota, United States, during the very late Cretaceous Period, 66 million years ago.  From snout to tail it was estimated to measure about eighteen feet long, which would have made it one of the largest dromaeosaurs known. Other dinosaurs that would have been from the same environment include Tyrannosaurus, Triceratops, Pachycephalosaurus, Edmontosaurus, Anzu, and Acheroraptor.  The genus name, Dakotaraptor, translates to "Dakota Thief/Hunter" in reference to where it was found.

Life restoration of what the creature associated with Dakotaraptor MAY have looked like if it was indeed an unenlagiine. (I included it's other misidentified parts too if you know what to look for!)

Since the initial discovery and publication, many the fossils associated with Dakotaraptor have, under more close examination, turned out to be from other animals.  The original bones weren't found articulated in any sort of death position, but were more jumbled up in what likely used to be the bottom of a body of water, so it makes sense that multiple different dead animals ended up there over time and were eventually fossilized.  Some of the bones turned out to belong to the large oviraptorosaur, Anzu, as well as Tyrannosaurus, and even a prehistoric Soft-shelled turtle, called Axestemys.  

Photograph of what was originally thought to be the "killer" retractable toe claw of Dakotaraptor that has since been recognized as possibly being from a Tyrannosaurus hand.

That being said there are still a few bones that were associated with Dakotaraptor that as of now appear to be from some kind of large dromaeosaur.  More recent peer reviewed research suggests Dakotaraptor may actually belong to the unenlagiine branch of dromaeosaurs, the group known for having very long narrow snouts, based on what little material there is.  Until these bones can be formally studied further, we may never know for sure.

References

Arbour, V.M.; Zanno, L.E.; Larson, D.W.; Evans, D.C.; Sues, H. (2015). "The furculae of the dromaeosaurid dinosaur Dakotaraptor steini are trionychid turtle entoplastra". PeerJ. 3: e1957.

DePalma, Robert A.; Burnham, David A.; Martin, Larry D.; Larson, Peter L.; Bakker, Robert T. (2015). "The First Giant Raptor (Theropoda: Dromaeosauridae) from the Hell Creek Formation.".Paleontological Contributions (14).

Jasinski, Steven E.; Sullivan, Robert M.; Dodson, Peter (2020-03-26). "New Dromaeosaurid Dinosaur (Theropoda, Dromaeosauridae) from New Mexico and Biodiversity of Dromaeosaurids at the end of the Cretaceous". Scientific Reports. 10 (1): 5105.

Hartman, S.; Mortimer, M.; Wahl, W. R.; Lomax, D. R.; Lippincott, J.; Lovelace, D. M. (2019). "A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight". PeerJ. 7: e7247.