This large Dromaeosaur was the dominant raptor of the upper Cretaceous period in North America. This theropod was rather small at 7 feet or so in length, but made up for its size with a large mouth full of serrated teeth. Like the other raptors they possessed a large "sickle" claw on each foot. It probably hunted in packs and may have been feathered. Fossil remains include well preserved teeth, bones, and claws, and are highly valued by collectors. These top quality specimens were all legally collected from private lands in the northwestern US. Late Cretaceous, Hell Creek Fm. (or equivalent), 66 MYA. Note - the large Hell Creek (Lance Creek) Dromaeosaur species has not been named to date.
Note - Hell Creek Formation named raptor dinosaurs. There are only two named raptor dinosaurs in the Hell Creek / Lance Creek Formations - Acheroraptor temertyorum (2013) with a distinct ribbed appearance of the enamel running the full length of the crown. Dakotaraptor steini (2015) was a large raptor possessing teeth with consistent characteristics with the typical big Hell Creek raptor teeth. The large Hell Creek raptor teeth may or may not all be Dakotaraptor teeth. Both are Dromaeosaurid raptor dinosaurs. There is a possibility for additional Dromaeosaur raptors to be named since many teeth do not fit the characteristics of the two named Dromaeosaurid raptor dinosaurs.
Dakotaraptor steini appears to be a very scarce raptor based upon my large group of smaller eastern Montana Hell Creek Fm. theropod teeth. I found only find a few of them in my sample. As reported in the Fossil Forum, I focused on the following characteristics for an adult Dakotaraptor tooth.
1) Smooth Crown - These teeth do not have the vertical ridges found in Acheroraptor and are larger and beefier
2) Serration Density - The serrations on the mesial (outer) edge are greater than the distal ( inside ) carina (measured midline). I take these as the minimum amount of serrations required. Much more serrations than a small Nanotyrannus tooth.
Mestai: 5-6 serration/mm
Distal: 4-5 serrations/mm
3) Carina Shape/Location
Distal: Extends to the base of crown
Mesial: Often does not reach the base and is straight. Typically ends 1/3 from the base.