Researchers have found an ancient monitor lizard with a fourth eye — a discovery that may signal a new wrinkle in the way eyesight evolved in vertebrates.
“This tells us how easy it is, in terms of evolution, for a complex organ to self-assemble under certain circumstances,” said Yale paleontologist Bhart-Anjan Bhullar, co-author of a new study in the journal Current Biology. “Eyes are classically conceived of as these remarkably complex structures. In fact, the developing brain is just waiting to make eyes given the right signals.”
In the study, researchers from Yale and the Senckenberg Research Institute in Germany present evidence that pineal and parapineal eyes, located on the top of the head, were present simultaneously in Saniwa ensidens, an extinct monitor lizard that lived nearly 50 million years ago.