Denversaurus

Although at one point treated as a junior synonym of Edmontonia by some taxonomists, current research indicates that it is its own distinct nodosaurid genus.

In 1986, the paleontologists Kenneth Carpenter and Brent Breithaupt described DMNH 468 which was a specimen of a late Maastrichtian nodosaurid, tentatively assigned to Edmontonia sp., discovered from the lower Hell Creek Formation of South Dakota.

Bakker referred a second fossil to the species, specimen AMNH 3076, a skull found by Brown and American Museum of Natural History paleontologist Roland T. Bird at the Tornillo Creek in Brewster County, Texas, in a layer of the poorly dated Upper Cretaceous Aguja Formation, possibly from the Maastrichtian too.

[15][16] In 2010, American paleontologist Gregory S. Paul estimated the length of Denversaurus at 6 metres (20 ft) and its body mass at 3 tonnes (3.3 short tons).

[9] Robert T. Bakker considered Denversaurus distinct from Edmontonia and Chassternbergia in having a skull that was wide at the rear and a more rearward position of the eye sockets.

According to American paleontologist Kenneth Carpenter, the greater width of both the holotype and the referred specimen was due to crushing.

[3] In 2015, vertebrate anatomist and paleontologist Michael Burns published an abstract concluding that Denversaurus was different from Edmontonia, but similar to Panoplosaurus in having inflated, convex, cranial sculpturing with visible sulci, or troughs, between individual top skull armour elements, but is distinct from Panoplosaurus in having a relatively wider snout.

Original skull and osteoderms on Display at Black Hills Institute of Geological Research
Size comparison