Last episode we featured Lythronax, the oldest-known North American tyrannosaur and a close relative of Tyrannosaurus rex. But tyrannosaurs weren’t the only big carnivores to tromp through the Mesozoic of North America. Before the tyrant lizards were huge, there was another giant terrorizing the American West: Siats! Named for a Ute mythological giant, Siats was a bus-sized carnivore in the middle Cretaceous of Utah (99 million years ago). The giant had close relatives - the neoventors - on almost all the continents. This is a bit of a mystery because the continents were getting spread out by 99 million years, making it tough to explain how the neovenators conquered the world. In North America, this global dynasty replaced another family of giants: the carcharodontosaurs which included Acrocanthosaurus the top carnivore of the Early Cretaceous of Western and Eastern North America. The discovery of Siats shows different lineages of carnivorous dinosaurs could get really big and T. rex i
