A newfound South American dinosaur had a tail like a war club

A new species of armored dinosaur from subantarctic Chile boasted a large tail weapon that looked dramatically different from those found on its relatives, and may shed light on a mysterious phase in the group’s evolution. 

Scientists found the mostly-complete skeleton in 2018 in the Río de las Chinas Valley of Chilean Patagonia and determined it to be roughly 71.7 to 74.9 million years old, dating it to the late Cretaceous. When they further examined the skeleton, the researchers found a baffling mixture of features typically seen in ankylosaurs and stegosaurs. However,…