LOS ANGELES — Scientists have finally identified a new species of
megamouth shark that prowled the oceans about 23 million years ago,
nearly 50 years after the first teeth were discovered and then
forgotten.
The ancient shark likely prowled both deep and shallow waters for plankton and fish, using its massive mouth to filter food.
"It was a species that was known to be a new species for a long time,"
said study co-author Kenshu Shimada, a paleobiologist at DePaul
University in Chicago. "But no one had taken a serious look at it," said
Shimada, who described the new species here at the 73rd annual meeting
of the Society for Vertebrate Paleontology. [
8 Weird Facts About Sharks]
Shark teeth
Scientists first found shark teeth from the species in the 1960s, but
at the time, there were no similar living creatures, so scientists
didn't quite know what to make of the find. Over time, researchers
turned up hundreds of similar teeth along the coast of California and
Oregon. All the specimens were tossed in a drawer and forgotten in the
collections of the Los Angeles County Museum and a few other California
museums.
An illustration of what the extinct megamouth shark would have looked like
Then in 1976, scientists discovered
the modern megamouth shark, dubbed
Megachasma pelagios,
which feeds exclusively on shrimplike creatures called plankton. The
sharks use their mammoth mouths to engulf plankton-filled water, forcing
the water through gills equipped with a filtering apparatus called gill
rakers, which direct plankton into the digestive track.
The monster beast is also a vertical migrator, meaning the shark lurks in the deep ocean during the day, but comes up to the shallow surface waters chasing plankton swarms at night, Shimada said.
Scientists haven't officially named the new species yet, but the genus will be called Megachasma, Shimada said.
