''Syllipsimopodi'' is an extinct member of the

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

subclass

Coleoidea Subclass (biology), Subclass Coleoidea, or Dibranchiata, is the grouping of cephalopods containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e., octopuses, squid and cuttlefish). Unlike its extant sister group, ...

belonging to the clade Vampyropoda, which includes

octopuses An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish ...

(Octopoda) and vampire squids (Vampyromorphida). The type and only known species is ''Syllipsimopodi bideni'', named in honor of US President Joe Biden, and to raise awareness of his climate change policies. The well-preserved

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

fossil was found in the

Bear Gulch Limestone The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often considere ...

deposit in the US state of

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

in 1988, and donated that year to the

Royal Ontario Museum The Royal Ontario Museum (ROM) is a museum of art, world culture and natural history in Toronto, Ontario, Canada. It is one of the largest museums in North America and the largest in Canada. It attracts more than one million visitors every year ...

by one B. Hawes, designated ROMIP 64897. The species lived during the (

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

) mississippian 330.3 to 323.4 million years ago pushing back the group of

cephalopods A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, an ...

by 81.9 million years. The cephalopod was named after Joe Biden, who was

president of the United States The president of the United States (POTUS) is the head of state and head of government of the United States of America. The president directs the executive branch of the federal government and is the commander-in-chief of the United Stat ...

at the time of its discovery. Whalen and Landman said in an interview that this name was chosen because they were, “encouraged by his plans to address climate change and to fund scientific research”.

Description

Individuals were long and had 10 arms with suckers, with two of the arms being longer than the others. It is currently the oldest known vampyropod and the oldest known cephalopod with biserial suckers on its ten robust appendages. The lead author of ''S. bideni'' states that it is the only known vampyropod that has 10 functional appendages, with all other species having eight arms, suggesting that their

ancestors An ancestor, also known as a forefather, fore-elder or a forebear, is a parent or (recursively) the parent of an antecedent (i.e., a grandparent, great-grandparent, great-great-grandparent and so forth). ''Ancestor'' is "any person from whom ...

had ten arms. The arms measure to about ~2.1 to 2.4 mm wide at the midlength. Two of the arms measure in at ~4.0 to 4.1 cm long making up 27% of the total body length. The elongated arms do not have obvious manus and are thinner than the other arms. The suckers are based along the midlength and are ~0.62 mm in diameter and are separated by ~0.5 mm. There is no evidence that the suckers were stalked. A possible funnel measuring ~2.4 mm long was preserved with a lateral edge of the head.

References

Octopodiformes Prehistoric cephalopod genera Mississippian cephalopods Carboniferous cephalopods of North America Fossils of the United States Fossil taxa described in 2022 {{Paleo-cephalopod-stub