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Shark bombshell: Huge 91-million-year-old previously unknown species linked to great white | Science | News


Dating back to the dinosaur-era, fossilised remains of what was later named the Cretodus houghtonorum were found in Kansas, US. Researchers uncovered 134 teeth, 61 vertebrae, 23 placoid scales and fragments of calcified cartilage preserved in sediments deposited on an ancient ocean called the Western Interior Seaway, that covered the middle of North America during the Late Cretaceous period. Traces of the shark were located and excavated by researchers Professor Kenshu Shimada and Dr Michael Everhart with help from local residents, Fred Smith and Gail Pearson. 

The ancient creature was estimated to be nearly 17-feet-long – the same size of the average great white shark seen in the oceans today – but that was not the only comparison.

Their research, published in the Journal of Vertebrate Paleontology, suggested that it was a rather sluggish shark and belonged to a group called Lamniformes that includes great whites as distant cousins.

Although a largely disarticulated and incomplete skeleton, it represented the best Cretodus specimen discovered in North America, according to Prof Shimada.

He added: “Much of what we know about extinct sharks is based on isolated teeth, but an associated specimen representing a single shark individual like the one we describe provides a wealth of anatomical information that in turn offers better insights into its ecology.

“As important ecological components in marine ecosystems, understanding about sharks in the past and present is critical to evaluate the roles they have played in their environments and biodiversity through time, and more importantly how they may affect the future marine ecosystem if they become extinct.”

During the excavation, Prof Shimada and Dr Everhart believed they had uncovered a specimen of Cretodus crassidens, a species believed to have originated from the UK and reported commonly in North America. 

However, not a single tooth matched the records of original Cretodus crassidens specimens or any other known species of Cretodus.

Prof Shimada added in 2019: “That’s when we realised that almost all the teeth from North America previously reported as Cretodus crassidens belong to a different species new to science.”

The expert also believes this species of shark may have grown up to 22 feet.

READ MORE: Shark bombshell: Mystery of world’s largest fish solved amid fear for ‘vulnerable’ species

He continued: “What is more exciting is its inferred large size at birth, almost four feet or 1.2 meters in length.

“This suggests that the cannibalistic behaviour for nurturing embryos commonly observed within the uteri of modern female Lamniformes must have already evolved by the late Cretaceous period.”

The research associates at the Sternberg Museum of Natural History decided to name the species houghtonorum in honour of Keith and Deborah Houghton, the landowners who donated the specimen to the museum for science.

Scientists continue to work on mapping out the history of sharks as they become increasingly concerned about great whites.

They say the Atlantic Ocean could experience an environmental collapse leading to the extinction of the apex predators.

California’s underwater kelp forests have been almost diminished following an explosion in urchins that eat the kelp, and that is due to a decline in sea otters that eat the urchins.

This is threatening the natural food chain of the area, which could completely collapse if great whites have no source of prey.

Bryan Franks, a Jacksonville University doctoral professor said at the time: “I can say with certainty you would lose stability, but there are so many factors involved it’s difficult to predict.

“Their prey would go up, then that third-level species would be depleted, but it’s difficult to model.  

“The classic example is the otters, the urchins and the kelp.”





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