in Arizona

Postosuchus kirkpatricki was a carnivorous predator that occupied a prominent place in the food chain of its ecosystem

suggesting that it could move quickly and efficiently

Height 99 mm

Irritator challengeri Seymouria in ArizonaIrritator challengeri is a genus of spinosaurid theropod dinosaur that lived during the Early Cretaceous Period, approximately 110 million years ago, in what is now Brazil. Its name comes from the Latin "irritator", in reference to the frustration of paleontologists upon discovering that the original fossil had been altered with plaster by the collectors who found it, and "challengeri" in honor of Professor Challenger, a fictional character created by