All teeth evolved from a single ancient sea predator, according to a new study.
The study explains how certain species evolved to grow teeth by pinpointing their likely origin in an armored ray that swam the oceans 100 million years ago.
They evolved from jagged spikes along the snout of the primitive sea predator named Ischyrhiza mira. Known as rostral denticles, they helped the beast forage–and fight off bigger fish. The finding is based on an analysis of fossils.
