Vampyronassa rhodanica is thought to be one of the oldest relatives of the modern-day vampire squid (Vampyroteuthis infernalis), which is the only remaining living species of its family. This modern form lives in extreme deep ocean environments, often with little oxygen, and feeds on drifting organic matter. Like V. infernalis, the body of V. rhodanica was mostly made of soft tissue. As this rarely fossilizes, little is known about the physical characteristics and evolutionary history of this family.

Despite the scarcity of fossil material from this family, Alison Rowe, from Sorbonne University and colleagues were able to study three well-preserved V. rhodanica specimens from La Voulte-sur-Rhône (Ardèche, France), dating to more than 164 million years ago. The eight-armed specimens were small, measuring around 10 cm in length, and had elongated oval-shaped bodies with two small fins.

They took them to the ESRF for non-destructive 3D imaging: "We used synchrotron tomography at the ESRF in order to better identify the outlines of the various anatomical features," says Rowe. However, the task was challenging, as Vincent Fernández, scientist at the ESRF, explains: "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. The coherence of ESRF beamline ID19 was therefore very important to perform propagation phase-contrast computed-tomography and track all the minute details, such as the suckers and small fleshy extensions, called cirri."