Katherine Kurowski

Sometimes in a toy dinosaur set you’ll find Dimetrodon, the one with the massive sail on its back. But Dimetrodon doesn’t belong with the dinosaurs. In fact, it’s not even a reptile. Although misidentified, Dimetrodon ranks as one of the most recognizable of extinct animals because the form of its sail is quite memorable. But it’s the sail’s function that is the real mystery.

Today’s beaked whales (Ziphiidae) dive hundreds of meters to chase after their prey: seafloor-living squids, fishes, and crustaceans. However, one remarkable fossil suggests an ancestral species of these whales found its food near the water’s surface.

In 2015, paleontologists reported the discovery of a new lizard species in southern Brazil. Gueragama sulamericana is the first known acrodontan lizard found in the New World, otherwise dominated by other lizards. G. sulamericana’s discovery overturns long-held hypotheses of and provides insights into the early evolution of lizards in South America.