The Hell Creek unenlagiid, teased as XXXXXXXX gen. nov., is a possible genus of unenlagiine dinosaur that lived in Montana during the Late Cretaceous.
History[]
A single well preserved metatarsal was recovered by Clint Boyd from a quarry in the Hell Creek Formation while on the hunt for Thescelosaurus. He plans on publishing the remains, having searched the same locality for more material. However, no additional remains have been found. The metatarsal was 3D scanned[1]. Thus, the unenlagiid identification is still tentative[2]. Thomas Holtz Jr. thinks the remains could be of a small deinonychosaurian, such as a halszkaraptorine similar to Mahakala[3]. Boyd teased a manuscript on October 20, 2021, showing a new dromaeosaurid known as "XXXXXXXX gen. nov." being named by him and Stephanie Drumheller as a new genus and species. He states it was found while hunting for thescelosaurids[4]. Boyd thinks the paper may be published in about a year if the peer review process is quick[5].
Classification[]
On October 21, 2021, Clint Boyd shared an image depicting a cladogram from a manuscript naming a new genus of Hell Creek dromaeosaur. Here, he and Drumheller use unenlagiinae as a dromaeosaurid subfamily. He states that this cladogram is extremely early, and that it may be placed much closer to unenlagiines as Neuquenraptor once more material is discovered since it "matches well"[6][7]. Their unresolved tentative placement can be seen below, with Dakotaraptor and Acheroraptor yet to be added to the dataset[8]:
| |||||||||||||||||||||||||
Description[]
The specimen bears distal curvature preserved poorly in most dromaeosaurs[9]. Deeply-grooved distal articulation present in the fossil is consistent in dromaeosaurs, with the lack of a plantar ridge consistent with Mahakala[10].
References[]