Giant plankton-eating fish prowled the earth's waters between 172 million and 66 million years ago. Two Sternberg Museum of Natural History associates joined five other scientists in publishing this revelation in the past Feb. 19 issue of the prestigious scientific journal Science.
Now, Discover Magazine has heralded their discovery as one of the top 100 science stories of 2010. The findings, sparked by research on a fossil originally found by a Fort Hays State University student, fill in a 106-million-year gap in the fossil record.
"Giant plankton-feeders in our modern oceans -- baleen whales, basking sharks and manta rays -- include some of the largest living animals," said Mike Everhart, Sternberg Museum adjunct curator of paleontology and one of seven co-authors of the paper. "The fact that such creatures appeared to be missing from the fossil record for hundreds of millions of years has been an ongoing mystery among marine paleontologists."
In 1971, FHSU undergraduate student Chuck Bonner found a fossil specimen in Logan County that was thought to be the remains of a giant swordfish. Collected later that year by his father, Marion, and his brother, Orville, the specimen was donated to the University of Kansas. Forty years later, a team of scientists closely examined the fossil and found toothless jaws supporting a gaping mouth and long, rod-like bones that contributed to the fish's ability to filter enormous quantities of plankton from the ocean. The team named this fish Bonnerichthys gladius.
"I started examining museum collections and found more examples that had been overlooked or misidentified," said Dr. Matt Friedman, lecturer in palaeobiology at Oxford University, Oxford, England.
Revisiting previously collected fossils netted the team evidence that this unique group of fishes thrived for over a hundred million years and colonized many parts of the globe.
A much more recent specimen of the fish was discovered by FHSU graduate and Sternberg Museum Research Associate Dr. Kenshu Shimada while on a field trip with Everhart in 2008. Donated to the Sternberg Museum of Natural History by landowners Mahlon and Carolyn Tuttle of Quinter, it has been placed on display in the museum.
"It's the most complete specimen of Bonnerichthys in the world," said Everhart, founder of the "Oceans of Kansas" website and an authority on marine fossils of the Smoky Hill Chalk. "The ancestors of large modern filter-feeders such as baleen whales and whale sharks only appeared after the extinction of Bonnerichthys and its relatives, suggesting that today's filter-feeders evolved to fill the ecological vacancy left by the extinction of these plankton-eating contemporaries of the dinosaurs."
For more information about the discovery, contact the Sternberg Museum at 785-628-4286. The "Oceans of Kansas" website is located at http://www.oceansofkansas.com.