Tooth Be Told: Prehistoric Sharks Didn’t Need Serrations to Snack on Whales
When we think of the great white shark, we often picture its iconic serrated teeth tearing through prey in a swift and deadly strike. These blade-like teeth, shaped by millions of years of evolution, help the modern Carcharodon carcharias feast on energy-rich marine mammals like seals and dolphins. But what about their ancient relatives, before those serrated edges ever evolved?
A comparison between a serrated modern great white shark tooth on the left, and an unserrated fossil white shark tooth on the right, from of the Calvert Marine Museum.
A recent study published in Acta Palaeontologica Polonica by Godfrey et al. (2025) has changed the narrative. Two fossilized marine mammal vertebrae, one from a small dolphin and the other likely from a baleen whale, reveal direct evidence of predation by Carcharodon hastalis, a Miocene ancestor of the modern great white shark. What's astonishing? These sharks didn’t yet have serrated teeth.
Instead, their large, triangular teeth were smooth-edged, which had long been interpreted as a limitation, perhaps restricting them to hunting smaller fish. But the discovery of two fossil vertebrae from Maryland’s Calvert Cliffs, each with an embedded hastalis tooth, reveals that these sharks were in fact targeting large prey like dolphins and whales over 15 million years ago. It’s the first concrete fossil evidence of this behavior, and it may explain why serrated teeth evolved in the first place: to more efficiently dismantle larger prey.
Peering into Prehistory… in Virtual Reality
What makes this study so compelling isn’t just the discovery; it’s also how the fossil evidence was analyzed.
To truly understand the depth of the shark tooth’s penetration into the fossil whale vertebra (catalogued as CMM-V-11947), researchers turned to cutting-edge imaging and visualization. A CT scan of the fossil was first performed at Johns Hopkins University, capturing the internal structure of the bone and the embedded tooth in precise detail.
A rendering, performed in syGlass, of the whale vertebra, revealing the embedded shark tooth within.
The subsequent analysis of the image volume in the syGlass virtual reality platform allowed for precise characterization of the fossil evidence. Researcher used syGlass to reconstruct, from the stacked 2D image planes of the CT scan, an immersive 3D visualization of the fossil. With VR controllers, the team could manipulate the image in real time, placing oblique clipping planes through the vertebra, adjusting contrast and windowing, and even measuring the exact length and angle of the embedded tooth.
The syGlass volume rendering engine allowed the team to step inside the fossil, exploring this intimate interaction between predator and prey in a way that traditional image visualization simply can’t match. The 3D stereoscopic environment gave paleontologists the ability to see inside the vertebra, revealing how deeply the tooth had pierced the bone and how the vertebral tissue responded around the foreign object.
This digital autopsy in VR provided compelling evidence that C. hastalis, even without serrations, was fully capable of tackling large marine mammals. It also showcased how new visualization tools like syGlass are revolutionizing paleontology, helping scientists extract deeper meaning from fossils without damaging them.
Rethinking Evolution with Modern Tech
This discovery pushes back the timeline of shark-on-mammal predation and invites a fresh look at how anatomical features evolve. It’s possible that feeding behaviors drove the emergence of serrations, not the other way around.
Thanks to the power of CT scanning and immersive virtual reality, the team behind this study didn’t just uncover a fascinating fossil: they opened a new window into shark evolution, ecology, and behavior. In the words of lead author Dr. Stephen J. Godfrey, “The fossil record, when paired with emerging technologies, continues to surprise us. We’re now able to see ancient life with new eyes.”
And thanks to tools like syGlass, sometimes those eyes are wearing a VR headset.
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