Paleobiologist Dr. Kenshu Shimada has had a lifelong passion for fossil sharks, sparked by discovering his first megalodon tooth at just 13 years old. His curiosity intensified when he watched the 2018 film The Meg, which portrayed the long-extinct megalodon as surviving in modern times, and depicted it as excessively larger than previously believed.
The true size of the megalodon has been elusive, with no complete skeletons ever found. However, Shimada’s recent research indicates that this ancient predator could have reached lengths of up to 24 metres, surpassing previous estimates by up to 9 metres. His findings, published in Palaeontologia Electronica, shed new light on the megalodon’s appearance, suggesting it may have had a more streamlined physique akin to a lemon shark, rather than the bulky frame often associated with great white sharks.
Shimada stresses that the megalodon is not simply a gigantic version of the great white, proposing a shift in how we understand its form and size. This new perspective could inform both scientific understanding and how this creature is portrayed in media and fiction, as well as offering insights into the nature of marine growth.
Unlike what is portrayed in The Meg, the megalodon thrived between 15 and 3.6 million years ago and never coexisted with humans. It held the title of apex predator in oceans around the globe. While its teeth are frequently discovered due to their durability, the megalodon’s cartilaginous skeleton, which is not preserved well in fossils, complicates our understanding of its size and shape. Current known fossils, including parts of vertebrae, support the existence of large specimens, but many are without the distinct megalodon teeth.
Shimada’s research involved comparing proportions from 145 species of living and 20 extinct sharks to model the megalodon’s body shape. He concluded that a slender, elongated form would allow for increased size while maintaining movement efficiency in water, contrasting with stockier varieties. This concept not only alters the understanding of the megalodon but may also explain the variations in size among marine vertebrates.
Dr. Stephen Godfrey, a curator at the Calvert Marine Museum and not part of Shimada’s study, expressed astonishment at the suggested resemblance to lemon sharks and the drastic increase in estimated size. He acknowledges that a long, slender body could indeed enhance hydrodynamic efficiency.
Ultimately, for definitive answers regarding the megalodon’s true size and shape, complete skeleton discoveries would be necessary. Like Shimada, many researchers await further fossil findings to validate or challenge these groundbreaking theories.