Figure 4. Pie chart of the time averaged census for large-bodied dinosaurs from the entire Hell Creek Formation in the study area.

Triceratops is the most common dinosaur at 40% (n = 72); Tyrannosaurus is second at 24% (n = 44); Edmontosaurus is third at 20% (n = 36) followed by Thescelosaurus at 8% (n = 15), Ornithomimus at 5% (n = 9), and Pachycephalosaurus and Ankylosaurus at 1% (n = 2).