Nature & Environment
Archaeologists Uncover Fossils from Earliest-Known Ancient Shark Nursery
Catherine Griffin
First Posted: Jan 08, 2014 07:16 AM EST
Archaeologists have uncovered one of the earliest known shark nurseries to have existed. They've found the spot where long-snouted Bandringa sharks migrated downstream from freshwater swamps to a tropical coastline to spawn 310 million years ago. The findings reveal a bit more about this unusual species that acted a bit like the salmon of today.
Bandringa sharks were bottom-feeding predators that lived in an ancient river delta system that spanned what is the Upper Midwest today. Their migratory behavior is still seen in sharks to this day, but the fact that they moved from freshwater to saltwater is highly unusual for sharks. Even so, Bandringa sharks were likely one of the earliest close relatives of modern sharks. The new fossil evidence reveals a bit more about their behaviors and their appearance.
"This pushes migratory behavior in sharks way back," said Lauren Sallan, one of the researchers, in a news release. "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 Bandringa looked a bit like a present-day sawfish and paddlefish; it had a spoon-billed snout up to half its body length and while juveniles were just four to six inches long, adults could grow up to 10 feet in length. New findings also revealed that Bandringa sharks had downward-directed jaws ideal for suction-feeding off the bottom, needle-like spines on the head and cheeks, and a complex array of sensory organs on both the extended snout and body that were suited for detecting prey in the murky water.
The new fossils that the archaeologists found also showed a bit more about how the Bandinga reproduced. Females traveled downstream to a tropical coastline to lay their eggs in shallow marine waters. The eggs themselves were enclosed in egg cases.
"This is the first fossil evidence for a shark nursery that's based on both egg cases and the babies themselves," said Sallan in a news release. "It's also 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."
The findings reveal a bit more about these extinct sharks. In addition, they show how migration patterns were present even in ancient species of sharks which tells scientists a bit more about the sharks of today.
The findings are published in the Journal of Vertebrate Paleontology.
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First Posted: Jan 08, 2014 07:16 AM EST
Archaeologists have uncovered one of the earliest known shark nurseries to have existed. They've found the spot where long-snouted Bandringa sharks migrated downstream from freshwater swamps to a tropical coastline to spawn 310 million years ago. The findings reveal a bit more about this unusual species that acted a bit like the salmon of today.
Bandringa sharks were bottom-feeding predators that lived in an ancient river delta system that spanned what is the Upper Midwest today. Their migratory behavior is still seen in sharks to this day, but the fact that they moved from freshwater to saltwater is highly unusual for sharks. Even so, Bandringa sharks were likely one of the earliest close relatives of modern sharks. The new fossil evidence reveals a bit more about their behaviors and their appearance.
"This pushes migratory behavior in sharks way back," said Lauren Sallan, one of the researchers, in a news release. "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 Bandringa looked a bit like a present-day sawfish and paddlefish; it had a spoon-billed snout up to half its body length and while juveniles were just four to six inches long, adults could grow up to 10 feet in length. New findings also revealed that Bandringa sharks had downward-directed jaws ideal for suction-feeding off the bottom, needle-like spines on the head and cheeks, and a complex array of sensory organs on both the extended snout and body that were suited for detecting prey in the murky water.
The new fossils that the archaeologists found also showed a bit more about how the Bandinga reproduced. Females traveled downstream to a tropical coastline to lay their eggs in shallow marine waters. The eggs themselves were enclosed in egg cases.
"This is the first fossil evidence for a shark nursery that's based on both egg cases and the babies themselves," said Sallan in a news release. "It's also 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."
The findings reveal a bit more about these extinct sharks. In addition, they show how migration patterns were present even in ancient species of sharks which tells scientists a bit more about the sharks of today.
The findings are published in the Journal of Vertebrate Paleontology.
See Now: NASA's Juno Spacecraft's Rendezvous With Jupiter's Mammoth Cyclone