By the start of the Triassic, all the Earth's landmasses had ... and paddle-finned plesiosaurs preyed on fish and ancient squid. The bottom rung of the food chain was filled with microscopic ...

Working alongside paleobiologists Michelle Stocker and Sterling Nesbitt with junior microbiology major Maranda Stricklin, Stack drew this conclusion by analyzing a fossilized Triassic-era fish ...