The contemporary vampire squid is a mysterious creature. It lives a sluggish existence deep in the water, far from the shore, where it feeds on whatever dead organisms float past it on their way to the ocean floor.
Was life always like this? This is a difficult subject to answer for species such as squid, octopuses, and cuttlefish, as these organisms (coleoids, evolutionary cousins) are identified by what they lack: a hard shell. This means they lack bodily parts that predispose them to fossilization. Conditions must be ideal for the soft body of a coleoid to be preserved as a fossil.
This is why Thursday’s publication of new research in the peer-reviewed journal Scientific Reports is so significant. Paleontologist Alison Rowe and her team analyzed rare fossilized remains of an extinct vampire squid relative using 3D imaging. According to their findings, Vampyronassa rhodanica may have been a bit more robust. Their findings suggest a ferocious eight-armed hunter that most likely seized prey with two powerful suction cups.
Rowe got down with Interesting Engineering to explain the study, what they discovered about Vampyronassa rhodanica, and what this new information tells about the ancient waters.
This interview has been condensed and clarified for length and readability.
Interesting Engineering: How did you and your co-authors conduct the research?
Alison Rowe: In this study, we scanned fossil and modern specimens using advanced X-ray imaging techniques. This allowed us to observe the previously unobserved interior architecture of the fossils, as well as view the surface soft tissue anatomy with significantly higher resolution.
We can demonstrate for the first time, based on a comparison between the fossil and the living form, that V. rhodanica possessed a combination of anatomical characteristics that are no longer present. This research provides a little window into the richness of Jurassic character combinations that have been lost.
IE: You compare V. rhodanica to the current vampire squid in the paper. Can you give us a quick overview of the vampire squid and its relatives?
Rowe: Actually, the vampire squid is not a squid. It resembles octopuses more than squids. It contains eight arms, like the octopus, and two filaments that are developmentally analogous to arms, making it equivalent to squid or cuttlefish (Decabrachia), which have ten arms. It bears cirri on its arms, similar to the incinerates [a suborder of the Octopoda order]. It has unique properties, such as its sucker attachment type and its gladius, which is a form of the organic interior shell.
It is specially adapted to life in the deep sea, frequently in locations with low oxygen levels, and it is an opportunistic detritivore that feeds on organic matter descending from the water column.
What samples were utilized for this study?
Rowe: We reanalyzed three fossil specimens of Vampyronassa rhodanica and two extant specimens of V. infernalis [the modern vampire squid] from the American Museum of Natural History and Yale Peabody Museum collections. In addition, we compared these specimens to other fossils described in the literature.
The V. rhodanica fossils were collected from the La Voulte-sur-Rhône Lagerstätte in the Ardèche area of France. In most lagerstatte, fossils are retained as impressions, but at La Voulte-sur-Rhône, specimens are frequently preserved in three dimensions.
IE: You provide a reanalysis of the fossils using modern techniques in the study. When was the initial investigation conducted, and what did those researchers discover?
Fischer & Riou described V. rhodanica for the first time in their 2002 publication. For their anatomical descriptions, the authors had to rely on observations of the outward form at the time of publishing. They were able to define numerous exterior characteristics, and based on this, they determined that this species was the vampire squid’s earliest possible relative (V. infernalis).
What new tools did you employ 20 years later to evaluate these fossils?
Using advanced X-ray-based imaging techniques at the Muséum National d’Histoire Naturelle in Paris and the European Synchrotron Radiation Facility Synchrotron, we reanalyzed several of the Vampyronassa rhodanica specimens described in the 2002 publication (ESRF, ID 19 beamline, Grenoble, France). We utilized the same X-ray techniques on the two current vampire squid at the American Museum of Natural History.
We were able to detect the boundaries of anatomical structures and recreate them in three dimensions using this data.
What did this analysis uncover?
Rowe: The outcomes were enthralling. For instance, the resolution we were able to achieve on the suckers of V. rhodanica was unknown before the collection of these data. We were able to discover that the sucker attachment of V. rhodanica is identical to that of current V. infernalis, albeit the general morphology of the sucker itself is octopus-like.
What do these observations say about the lifestyle and behavior of V. rhodanica?
Rowe: Although we cannot examine how V. rhodanica uses its suckers. By comparing conserved anatomical traits with those of modern coleoids, such as suckers and cirri, and understanding how they work now, we can deduce how the Jurassic V. rhodanica may have utilized the same structures. Based on functional similarities with modern coleoids, the combination of traits observed in the arm crown of V. rhodanica as well as their streamlined, muscular mantle suggests that they were adapted to a pelagic, predatory existence.
IE: Were you shocked? Your findings were consistent with the initial analysis, right?
Rowe: The soft tissues of current coleoids provide a great deal of information about their lifestyle, even though this information is rarely preserved in fossils. Based on prior research, we had a notion of the outward characteristics that had been retained; nonetheless, the resolution with which we could see the finer details of these issues in the scans was astounding.
IE: How do your findings affect the current understanding of V. rhodanica? Do they reveal information about its larger habitat or ecology?
Rowe: The V. rhodanica lifestyle differs from that of the modern vampire squid. It is unknown when the lineage adapted to a deep-sea lifestyle, but new research has identified a fossil species of this family living in this environment during the Oligocene, approximately 33.9 to 23 million years ago. It is possible that the initial migration from shallower to deeper waters was prompted by competition in onshore habitats. The diversity of coleoid taxa at La Volute-Sur-Rhône (V. rhodanica and other species) demonstrates that Mesozoic coleoids occupied distinct ecological niches during the middle Jurassic.