An artist’s reconstruction of the newly described 328-million-year-old vampiropod. Credit: © K. Whalen
The description of the exceptionally preserved fossils pushes the age of Vampyropoda to almost 82 million years ago.
New research led by scientists from the American Museum of Natural History and Yale shows that the earliest ancestors of the group of animals that includes octopuses and vampire squids had not eight, but 10 arms. The study, which describes a new species of vampyropod based on a 328-million-year-old fossil that had not been previously described, pushes the age of the group back nearly 82 million years. The details were published March 8, 2022, in the journal Nature Communications .
“This is the first and only known vampiropod to possess 10 functional appendages,” said lead author Christopher Whalen, a postdoctoral researcher in the Museum’s Division of Paleontology and a National Science Foundation postdoctoral fellow in Yale’s Department of Earth and Planetary Sciences.
Vampyropoda are soft-bodied cephalopods, typically characterized by eight arms and an internalized chitinous shell or fin supports. Because they lack hard structures, Vampyropoda are not well represented in the fossil record. The new study is based on an exceptionally well-preserved vampyropoda fossil from the collections of the Royal Ontario Museum (ROM). Originally discovered in what is now Montana and donated to the ROM in 1988.
Whalen and co-author Neil Landman, curator emeritus in the museum’s Division of Paleontology, identified the fossil specimen as an entirely new genus and species, dating back about 328 million years, making it the oldest known vampyropod and extending the group’s fossil record by about 82 million years. In the new study, they also describe its 10 arms—all with preserved suckers—corroborating previous scientific arguments that the common ancestor of vampyropods also had 10 arms.
“Arm count is one of the defining characteristics that separates the 10-armed squid and cuttlefish lineage (Decabrachia) from the eight-armed octopus and vampire squid lineage (Vampyropoda). We have long understood that octopuses achieve the eight-armed number by eliminating the two vampire squid filaments and that these filaments are vestigial arms,” Whalen said. “However, all previously reported fossil vampyropoda that retain appendages have only 8 arms, so this fossil is arguably the first confirmation of the idea that all cephalopods have ten arms ancestrally.”
Two of the cephalopod’s arms appear to have been elongated compared to the other eight arms, and its torpedo-shaped body is reminiscent of modern squid. The fossil has been given the scientific name Syllipsimopodi . The genus name is derived from the Greek words “syllípsimos” for “prehensile” and “pódi” for “foot”—because it is the earliest known cephalopod to develop suction cups, allowing the arms, which are modifications of the mollusk foot, to better grasp prey and other objects. The species name honors the recently inaugurated (at the time of the paper’s submission) 46th President of the United States, Joseph R. Biden.
” Syllipsimopodi may have filled a niche more akin to extant squid, a mid-level aquatic predator,” Landman said. “It’s not inconceivable that they could have used their sucker-laden arms to extract small ammonoids from shells, or they might have ventured further ashore to prey on brachiopods, bivalves, or other shelled marine animals.”
Based on its age, characters, and phylogenetic position, the fossil challenges prevailing arguments for the origins of vampyropods, and the authors propose a new model for the evolution of coleoids (internally shelled cephalopods).
For more on this discovery, see New Species of Extended Vampire-Like Cephalopod with 10 Arms Named After Biden.
Reference: “Fossil coleoid cephalopod from the Mississippian Bear Gulch Lagerstätte sheds light on early vampyropod evolution” by Christopher D. Whalen and Neil H. Landman, March 8, 2022, Nature Communications .
DOI: 10.1038/s41467-022-28333-5
This study was supported in part by the Postdoctoral Fellowship in Biology Program of the US National Science Foundation (#2010822) and the Elis L. Yochelson Award by the Paleontological Society for Undergraduate Research.
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