"If you think about how long we've been looking for fossils around the world as a civilization -- which is maybe 200 years -- in (that time) we have found just three (sets of) fossils of this kind on the entire planet, and this most recent find from Australia is one of those three," Fitzgerald told CNN.
The species, carcharocles angustidens, is an ancient cousin to megalodon, thought to be the largest shark at an estimated 60 feet which became extinct about 2.6 million years ago, the Australian Associated Press reported.
Fitzgerald, noting the teeth were from the same species, led teams to further excavate the area in 2017 and January 2018 where they discovered more than 40 more teeth and part of a vertebra. Most belonged to the narrow-toothed shark, however many more smaller teeth, from the sixgill shark were found, suggesting they fed on the larger predator after it died.
An illustration of a great jagged narrow toothed shark being eaten by sixgill sharks. (Photo: Museums Victoria)
"Sixgill sharks still live off the Victorian coast today, where they live off the remains of whales and other animals," Fitzgerald said in a statement. "This find suggests they have performed that lifestyle here for tens of millions of years."
Mullaly donated the teeth to the museum where they are on display for the next six months.