Despite their intimidating moniker, modern-day vampire squid (Vampyroteuthis infernalis) lead a pretty laid-back life. They potter around in the deep ocean feeding on drifting organic matter that they catch using sticky cells that cover their long, slender tentacles.
Their Jurassic ancestor, Vampyronassa rhodanica, however, was a different story altogether. V. rhodanica were most likely aggressive predators that actively stalked the deep ocean in search of prey, a study carried out by researchers at Sorbonne University has found.
To make the discovery, the team produced high-resolution 3D scans of three well-preserved V. rhodanica specimens found in La Voulte-sur-Rhône in southern France, and compared them to scans of extant V. infernalis specimens scanned at the American Museum of Natural History in New York.
The specimens date back more than 164 million years, are around 10 cm long, and have elongated oval-shaped bodies accented by two small fins.
Fossils of V. rhodanica are incredibly rare as, like their modern-day counterparts, their bodies are largely formed of soft tissue.
The scans revealed that the suckers that lined each of animals’ eight arms and the spine-like fleshy protrusions, known as cirri, that run along the inside of the arms, were much more robust in V. rhodanica compared to V. Infernalis. They also found that the shape of V. rhodanica's arm crown – the structure that forms the base of its arms – was a different shape.
This suggests that V. rhodanica was an active predatory hunter that used its arms to clamp onto their prey before devouring it, the researchers say.
Like V. infernalis, however, the suckers of V. rhodanica were unlikely to be toothed like many modern species of squid.
"We believe that the morphology and placement of V. rhodanica suckers and cirri in the differentiated arm crown allowed V. rhodanica increased suction and sensory potential over the modern form, and helped them to manipulate and retain prey,” said lead researcher Alison Rowe.
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