Shell-eating shark from the dinosaur age

Ptychodus mortoni fossils

‘Shell Crusher’ Shark Swam Cretaceous Kansas

With 1,000 teeth in its jaw, the 88.7 million-year-old shark could pulverize its prey

THE GIST:

* Paleontologists have found the remains of a 33-foot-long shark from the Cretaceous.
* The shark, nicknamed the “shell crusher,” had 1,000 “pavement-like” teeth built for pulverizing the shells of marine animals.
* This animal lived at a time when many other species — reptiles, fish and others — grew to very large sizes.

Paleontologists have just identified the remains of a gigantic, 88.7-million-year-old shark nicknamed the “shell crusher.” The Cretaceous species could pulverize large, shelled animals with its 1,000 teeth, suggests a new study.

A handful of other fossils for the shark, Ptychodus mortoni, had been previously found and hinted that the species was extremely big. The new discoveries support that contention and reveal the shark likely grew to at least 33 feet in length and chomped on its prey with its 3-foot-long jaw.

Its specialized teeth were just as impressive as its body size.

“Unlike ‘conventional sharks,’ Ptychodus mortoni possessed pavement-like upper and lower dental plates consisting of juxtaposed rows of massive teeth suited for crushing,” lead author Kenshu Shimada, a research associate in paleontology at the Sternberg Museum of Natural History, told Discovery News.

“The shark could have practiced suction feeding, but larger prey, such as giant clams, would have required the shark to pick them up directly with its mouth from the bottom of the ocean floor,” added Shimada, who is also an associate professor in the Environmental Science Program and Department of Biological Sciences at DePaul University.

His team identified a portion of a right upper jaw, 19 teeth and multiple oral and dermal scales for the shark, now housed at the Sternberg Museum. The scientists originally found the remains embedded in a vertical rock cliff in Kansas called the Fort Hays Limestone. …

The known remains, described in a paper accepted for publication in the journal Cretaceous Research, along with prior finds suggest “Ptychodus possibly resembled the modern nurse shark, which has a broad, rounded head with a stout body.”

The two sharks, however, were not closely related to each other.

During the Late Cretaceous, this shark was probably a “sluggish bottom dweller” in a seaway covering today’s Kansas and other parts of North America. Based on additional remains excavated before at the site, the shark shared its marine habitat with carnivorous reptiles, such as mosasaurs and plesiosaurs, as well as fish and other sharks. At least one shark, Squalicorax, probably fed on Ptychodus.

Most of these animals had one thing in common: They were big.

Whale shark butchered for its fins in the Philippines: here.

A pampering session at the beauty salon always works wonders for morale – not just for humans, but also for sharks and manta ray fish. Australian scientists have discovered that these large marine creatures regularly congregate at certain spots on the Great Barrier Reef to be groomed by smaller fish: here.

It might sound like a mashup of monster movies, but palaeontologists have discovered evidence of how an extinct shark attacked its prey, reconstructing a killing that took place 4 million years ago: here.