Vampyronassa rhodanica is an ancient species of cephalopod that lived in the Jurassic oceans some 164 million years ago.
Vampyronassa rhodanica is thought to be one of the oldest relatives of the extant vampire squid (Vampyroteuthis infernalis), which lives in extreme deep ocean environments, away from the shoreline, often with little oxygen.
However, less is known about the physical characteristics of Vampyronassa rhodanica as the body is rarely found fossilized due to being largely formed of soft tissue.
In the new study, Sorbonne University researcher Alison Rowe and colleagues used a non-destructive 3D imaging technique to analyze three well-preserved specimens of Vampyronassa rhodanica from La Voulte-sur-Rhône, Ardèche, France.
The eight-armed creatures were small, measuring around 10 cm (3.9 inches) in length, and had elongated oval-shaped bodies with two small fins.
“We used synchrotron tomography in order to better identify the outlines of the various anatomical features,” Dr. Rowe said.
“However, the task was challenging,” added Dr. Vincent Fernández, a researcher at the European Synchrotron – ESRF and the Imaging and Analysis Centre at the Natural History Museum, London.
“The fossils are on small slabs, which are very difficult to scan. On top of that, soft tissues are preserved but we needed phase contrast imaging to visualize the faint density variation in the data.”
Similar to modern vampire squid, the suckers on Vampyronassa rhodanica were likely not toothed.
However, unlike vampire squid, the fossil specimens displayed evidence of robust suckers on the tips of two specialized, long dorsal arms.
Based on similar modern-day species, the researchers propose that Vampyronassa rhodanica used these suckers to create a watertight seal, producing a secure suction force.
“We believe that the morphology and placement of Vampyronassa rhodanica suckers and cirri in the differentiated arm crown allowed Vampyronassa rhodanica increased suction and sensory potential over the modern form, and helped them to manipulate and retain prey,” Dr. Rowe said.
“The presence of muscular suckers on each of the arms and sensory conical appendages for detecting prey suggests that Vampyronassa rhodanica was likely an active predatory hunter.”
“This is in contrast with its more opportunistic descendant the vampire squid, which has adapted to a low energy, deep ocean lifestyle.”
The study was published in the journal Scientific Reports.
A.J. Rowe et al. 2022. Exceptional soft-tissue preservation of Jurassic Vampyronassa rhodanica provides new insights on the evolution and palaeoecology of vampyroteuthids. Sci Rep 12, 8292; doi: 10.1038/s41598-022-12269-3
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