Utahraptor ostrommaysi

 

Utahraptor ostrommaysi (Kirkland, Gaston, and Burge, 1993) 
Dinosauria 
Theropoda 
Tetanurae 
Coelurosauria 
Maniraptora 
Paraves 
Dromaeosauridae (Raptors) 

Dromaeosaurinae 

Valanginian to Hauterivian (Early Cretaceous) 
Cedar Mountain Formation 
Utah, United States 

Length: 5 - 5.5 m 

The largest known dromaeosaurs (raptor), Utahraptor differs from the typical raptor build with proportionally shorter limbs, a proportionally shorter tail, and a big, blocky head with forward-tilting teeth at the tip of the lower jaw. 

Sunday, October 8th, 2023 

Dakotaraptor steini

Dakotaraptor steini (DePalma et al., 2015) 

Dinosauria 

Theropoda 

Tetanurae 

Coelurosauria 

Maniraptora 

Paraves 

Dromaeosauridae (Raptors) 

Maastrichtian (Late Cretaceous) 

Hell Creek Formation 

South Dakota, United States 

Length: 4.5 - 6 m 

If valid*, despite being one of the largest known dromaeosaurs (raptors), Dakotaraptor retains the relatively agile build of smaller dromaeosaurs like Deinonychus rather than the stocky build of similarly sized dromaeosaurs like Utahraptor. 

* Note: Dakotaraptor's taxonomic validity is currently uncertain and may represent a chimaera. 

Sunday, January 8th, 2023