(CN) — Uniquely preserved soft tissue from the Jurassic era offers insight into the anatomy and lifestyle of an ancient cephalopod, according to research published in Scientific Reports on Thursday comparing the fossilized remains of Vampyronassa rhodanica with its modern relative, the vampire squid.
The Latin name Vampyroteuthis infernalis translates to “vampire squid from hell,” but the foot-long cephalopod is more closely related to octopus than squid and isn’t particularly aggressive as it glides through the deep sea, passively feeding on zooplankton.
The last known species in its order, the vampire squid is considered a living fossil, seeming to have undergone very little evolutionary change over the last hundred million years.
Now researchers postulate the vampire squid’s ancestor, Vampyronassa rhodanica, which measured only four inches long, occupied a more active ecological niche hunting deep sea prey.
Soft tissue is rarely preserved in the fossil record, leaving large knowledge gaps in the evolutionary history of organisms like cephalopods.
“Tracing their evolutionary history allows us to better understand their patterns of diversity, responses to environmental pressures, and is important for the conservation and management of existing species,” explained the paper’s lead author Alison Rowe via email. Rowe is a researcher at Sorbonne Université in Paris.
Uniquely preserved three-dimensional tissue from the Jurassic Lagerstätte of La Voulte‑sur‑Rhône, in Ardèche, France, provided Rowe and others with rare insight into the life of the modern-day vampire squid’s oldest known relative.
“The preservation that occurs here is a result of the soft tissue being replaced by various iron-rich minerals, and the specimen becoming phosphatized,” Rowe explained. “This phosphatization supports the preservation of fine details like muscular tissue as we can identify in these V. rhodanica specimens.”
The dig site contains the remains from a bathyal ecosystem, which once thrived thousands of feet below the ocean’s surface. In addition to 20 V. rhodanica, archeologists uncovered a diverse array of species related to modern-day arthropods, sea worms, and fish as well as shelled bivalves and brachiopods.
"Synchrotron X‑ray microtomography and reconstruction of V. rhodanica allowed, for the first time, a high‑resolution re‑examination of external and internal morphology, and comparison with other fossil and extant species,” the paper explained. “The new data obtained demonstrate that some key V. infernalis characters, such as its unique type of sucker attachment, were already present in Jurassic taxa.”
Notably, V. rhodanica had many suckers on the end of two long dorsal arms. Similar appendages are used by modern organisms to make a watertight seal and suction force to capture and hold prey.
These suckers therefore could have helped the ancient cephalopod hunt deep sea prey, allowing it to occupy a vastly different ecological niche than its modern opportunistic offspring.
Rowe hopes to one day find specimen preserved with stomach contents to be able to verify what the hunter ate. She continues to study coleoids and other specimens preserved at the site.
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