Scientists uncovered fossils of a giant shark from the Lamniformes order in northern Australia, dating back approximately 115 million years. This discovery reveals that these large oceanic sharks attained immense sizes much earlier than previously assumed. The study is published in Communications Biology (ComBio:).
Lamniformes is an order of sharks often referred to as the mackerel sharks. It encompasses some of the most recognizable shark species, such as the great white shark and the mako shark, as well as lesser-known ones like the frilled shark and Megalodon (though Megalodon is often placed in its own order, this text follows the original grouping for similarity).
Vertebrae were discovered on the coast near Darwin, which was part of the Tethys Ocean during the Cretaceous period. Usually, only the teeth of sharks are preserved because their skeletons are cartilaginous, making large vertebrae a great rarity. The five elements found bore a striking resemblance to the vertebrae of the contemporary great white shark. However, while adult white sharks’ vertebrae reach about eight centimeters in diameter, the width of the fossil cartilaginous predator from Darwin exceeded 12 cm.
The morphology of the vertebrae allowed researchers to assign them to the Cardabiodontidae—enormous predatory sharks that inhabited the global ocean around 100 million years ago. Nevertheless, the new findings indicate that the Darwinian Lamniformes are about 15 million years older and were already reaching the sizes characteristic of Cardabiodontids at that time.
The authors estimate these sharks grew to six to eight meters long and weighed more than three tons, occupying the niches of apex predators during the group’s early evolutionary stages. They lived in shallow coastal waters and likely competed with large marine reptiles.
Researchers emphasize that this finding reshapes the timeline of shark evolution and highlights the importance of Australian fossils for comprehending ancient ecosystems. Every new fragment helps reconstruct the picture of oceans where immense predators reigned millions of years ago.
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