A collection of shark artifacts shows the lengthy and narrow nosed Bandringas moved to salt seawater from freshwater a minimum 310 million years ago for their offspring's birth The Daily Mail reported Friday.
Scientists found the fossils in Mazon Creek, Ill by a nuclear plant exposed to the air and with egg shells exactly like the fossil's counterpart from 310 years ago The Daily Mail reported.
'This is the first time we have eggs and fossilized hatchlings in the same place, proving it's a shark nursery," Lauren Sallan, co-author of the study told The Daily Mail. Sallan is also a a paleontologist at the University of Michigan, in Ann Arbor. "These sharks bred in the open ocean and spent the rest of their lives in fresh water," Sallan told The Daily Mail. "No shark alive today is known to do that. It's the earliest evidence for segregation, meaning that juveniles and adults were living in different locations, which implies migration into and out of these nursery waters," Sallan told The Daily Mail.
The fossil shark also had lengthy noses with electrical receptors or sensory organs in fish, sharks, skate fish, and electric eels according to Free Dictionary. The fossils also had spine-adorned head and cheeks The Daily Mail reported.
"This pushes migratory behavior in sharks way back," Sallan told The Daily Mail. 'These sharks bred in the open ocean and spent the rest of their lives in fresh water. No shark alive today is known to do that.'
The sharks also known as Bandringas are considered to be the most similar to modern sharks, and resemble sawfish, and paddlefish according to the findings The Daily Mail reported.
The sharks started out at 10 to 15 centimeters in length or four to six inches, and developed to three meters or 10 feet The Daily Mail reported.
