A prehistory of blindness

AUGUST 7, 2019

by University Of New England (Australia), University of New England

Fossils that had gone unstudied since the early 20thcentury helped a team led by University of New England (UNE) palaeontologist Dr Russell Bicknell to address a long-standing puzzle: were ancestors of the iconic horseshoe crab blind?

Examining fossil specimens housed within the New York State Museum and comparing them to other fossils from Australia, Bolivia, Canada, China, England, and the USA allowed Dr Bicknell and colleagues from the Museum and Harvard to determine that about 60 per cent of fossil horseshoe crab species showed no evidence of eyes.

Some of these fossils were collected as far back as 1865. Since these specimens were gathered in the 19th Century, the lack of evidence of eyes had persuaded generations of palaeontologists that the ancestors of modern horseshoe crabs were blind.

"We effectively ground-truthed that assumption, and found that to a degree, these statements were correct," Dr Bicknell said. "What those early investigators didn't have, and we did, was a more complete record of fossil horseshoe crabs."

More:
https://phys.org/news/2019-08-prehistory.html