An international team of researchers has discovered a new species of extinct shark. The team named it Megalolamna paradoxodon, which grew up to 10 meters or 33 feet in length.
The shark lived 20 million years ago during the early Miocene epoch. It belonged to Lamniformes, a group that includes mako sharks and modern-day great whites.
It is also part of the Otodontidae family, which also includes the extinct megalodon’, also known as megatoothed shark.
The researchers found fossilized teeth as big as 4.5 centimeters or 1.8 inches in California and North Carolina in the US, as well as in Peru and Japan.
The scientists add that Megalolamna paradoxodon had grasping-type front teeth and cutting-type back teeth, which it used to catch and slice medium-sized fish.
“It’s quite remarkable that such a large lamniform shark with such a global distribution had evaded recognition until now, especially because there are numerous Miocene localities where fossil shark teeth are well sampled,” points out the study’s lead author Kenshu Shimada, a paleobiologist at DePaul University.
The findings also indicate that the members of the megatoothed lineage should now be classified to the genus Otodus. Previously, sharks like megalodon are classified to the genus Carcharocles.
“The idea that megalodon and its close allies should be placed in Otodus is not new, but our study is the first of its kind that logically demonstrates the taxonomic proposition,” points out Shimada.
In a press release, the research team explains, “Because the megatoothed shark lineage simply represents a subset of Otodus, excluding megatoothed sharks would not reflect a full lineage for Otodus — an uncomfortable taxonomic condition referred to as ‘non-monophyletic.’ The inclusion of megatoothed sharks into Otodus would make the genus a much preferred complete lineage referred to as a ‘monophyletic group’ that is considered to be a next of kin to the new genus Megalolamna.”