A recent study of fish skulls in the form of fossils completely dismissed the popular recent theory that bony fish evolved from sharks. It also demonstrated that humans evolved from a category of ‘cartilaginous’ fishes.
By making use of X-Rays and CT scans, researchers observed the fossils codenamed ‘Janusiscus’ for its two faced feature, which comes from the Roman origin of a god named Janus who was two-faced.
There does not exist any division in the bottom of the skull, showing clues that its evolution has just started. Sharks in these present times also lack external skulls in a similar manner.
The scans also reported that the fossil has a smaller yet existent external skull. Researchers concluded that the sharks lost the bony skeletons on their faces early in their evolution.
The two features that the fossils have branched out to two families in the evolution history: bony fish and cartilaginous fish. The latter further evolved to land vertebrates and then to humans.
“This mix of features, some reminiscent of bony fishes and others cartilaginous fishes, suggests that humans may have just as many features that you might call ‘primitive’ as sharks,” Oxford University’s Department of Earth Sciences researcher Matt Friedman said.
Experts previously pinned sharks on the primitive stage of the evolution history because of its external features but recent findings led them to give sharks another look.
“Janusiscus has helped us to look at sharks differently,” said Martin Brazeau of Imperial College of London’s Department of Life Sciences.
‘The fossil provided researchers new evolutionary insights,’ Dr. Brazeau added.