An artist’s rendering of Bandringa, a 310 million-year-old shark originally found in fossil deposits from Mazon Creek, Illinois. University of Michigan paleontologist Lauren Sallan and a colleague say this bottom-feeding predator migrated to the ocean to spawn in shallow coastal waters and left behind fossil evidence of one of the earliest known shark nurseries. Painting by John Megahan, University of Michigan.
Sharks are known to be one of the most ancient creatures to still exist into the modern era, but just how far back they can really be surprising. The intriguing things we see in some of today’s sharks originated millions of years ago. Today we investigate more into this ancient shark relative, the Bandringa. The Bandringa lived between 307-315 million years ago, nearly 50 million before the first dinosaurs! Even more exciting about this ancient creature was its peculiar anatomy and migration patterns.
A common understanding of sharks in the modern era is the fact that all sharks must live in salt water to survive, with one very big exception (find out more with our post on bull sharks here). Scientists understand that sharks migrate and move throughout the world’s waters, but the Bandringa not only lived in the salty waters on the ancient coasts of land that would later form Illinois, Michigan, and Ohio in the United States, but also migrated into the inland fresh waters there as well. Like a salmon travelling upstream to have its young, evidence suggests that the Bandringa would return to fresh waters from their salty home to visit a type of nursery. Just as modern sharks can have special locations where they go to lay their eggs, so too did the Bandringa, with fossils of the Bandringa being found in these fresh waters alongside egg cases found in the same areas. Even more surprising is the fact that these ancient sharks displayed many of the same behaviors of their modern relatives today.
A full grown adult Bandringa could reach up to nearly 10 feet long from tip of its tail to its snout, and what a snout it had! Many modern comparisons find a similar relative in the sawfish of today, comparing the long noses between the two species. Modern sawfish use their noses to stir up the seafloor in their environment to reveal prey, leading researchers to believe that this ancient ancestor performed a similar action millions of years ago. Also, like the sawfish, the Bandringa would live in shallow marine areas so that it could hunt with its specialized snout. Perhaps it is a good thing that they lived in these marshy, swampy shallow areas; because of decomposing plant and animal matter in these shallow marine environments, when a Bandringa would die it would settle to the bottom of these silty areas, quickly covered by mud and there they would lay for millions of years as they turned into the fossils we discover today.
50 million years before the earliest dinosaurs appeared, the earliest of the relatives of the beautiful sharks of today were already well-developed and specialized for the world they lived in. The Bandringa is no exception, with its long snout and migration to fresh waters, these same behaviors are found in all sorts of fishes to this day!
GUEST BLOG POST WRITER: JOSHUA ROOKS
TFUI Founder Melissa C. Marquez is author of all animal bios and "Behind the Fins" segments.
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