The perfectly shaped cutting tools that were the teeth of the mighty megalodon were the result of millions of years of evolution, according to a new study published in the Journal of Vertebrate Paleontology.
Victor Perez, a doctoral student in geology at the Florida Museum of Natural History, analyzed 359 fossilized teeth found in the Calvert Cliffs on the western shore of Maryland’s Chesapeake Bay that belonged to the megalodon and its immediate ancestor, Carcharocles chubutensis. This unique geological site, which was underwater for millions of years, provided an uninterrupted fossil record between about 20 to 7.6 million years ago, a period that overlaps with these megatooth sharks.
The study found that the evolution of megalodon teeth took place over a period of over 12 million years. Megalodon’s earliest ancestor, Otodus obliquus, sported three-pronged teeth that could have acted like a fork for grasping and tearing fast-moving fishes.
In later megatooth shark species, teeth flattened and developed serrated edges, transitioning to a knifelike shape for killing and eating fleshy animals like whales and dolphins.
“This transition was a very long, drawn-out process, eventually resulting in the perfect cutting tool—a broad, flat tooth with uniform serrations,” Perez said. “It’s not yet clear why this process took millions of years and why this feature was lost.”
Perez’s analysis also suggested that Megalodon’s hunting style was likely a “single-strike tactic,” designed to immobilize its prey and allow it to bleed out.
“It would just become scavenging after that,” he said. “A shark wouldn’t want to grab and hold onto a whale because it’s going to thrash about and possibly injure the shark in the process.”
The vast majority of teeth analyzed in the study were discovered by amateur fossil collectors and donated to museum collections.
“This study is almost entirely built on the contributions of amateur, avocational paleontologists,” he said. “They are a valuable part of research.”