''Nesonektris aldridgei'' is an extinct deuterostome

chordate A chordate () is an animal of the phylum Chordata (). All chordates possess, at some point during their larval or adult stages, five synapomorphies, or primary physical characteristics, that distinguish them from all the other taxa. These fi ...

from the Late

Botomian Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission on ...

-aged

Emu Bay Shale The Emu Bay Shale is a geological formation in Emu Bay, South Australia, containing a major Konservat-Lagerstätte (fossil beds with soft tissue preservation). It is one of two in the world containing Redlichiidan trilobites. The Emu Bay Shale ...

Lagerstätte A Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These f ...

Kangaroo Island Kangaroo Island, also known as Karta Pintingga (literally 'Island of the Dead' in the language of the Kaurna people), is Australia's third-largest island, after Tasmania and Melville Island. It lies in the state of South Australia, southwest ...

, Australia. So far, it is the fourth described

vetulicolia VetulicoliaThe taxon name, Vetulocolia, is derived from the type genus, ''Vetulicola'', which is a compound Latin word composed of ''vetuli'' "old" and ''cola'' "inhabitant". is a taxon (either phylum or subphylum in rank) encompassing several ex ...

n that is not restricted to the

Maotianshan Shales The Maotianshan Shales are a series of Early Cambrian deposits in the Chiungchussu Formation, famous for their '' Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized organisms or traces. The Maotianshan Shales ...

(the other three being ''

Ooedigera ''Ooedigera peeli'' is an extinct vetulicolian from the Early Cambrian of North Greenland. The front body was flattened horizontally, oval-shaped, likely bearing a reticulated or anastomosing pattern, and had 5 evenly-spaced gill pouches along ...

'' of

Sirius Passet Sirius Passet is a Cambrian Lagerstätte in Peary Land, Greenland. The Sirius Passet Lagerstätte was named after the Sirius sledge patrol that operates in North Greenland. It comprises six places in Nansen Land, on the east shore of J.P. Koch F ...

, ''

Banffia ''Banffia'' is a genus of animals described from Middle Cambrian fossils. The genus commemorates Banff, Alberta, near where the first fossil specimens were discovered. Its placement in higher taxa is controversial. It is considered to be a memb ...

'' of the

Burgess Shale The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fo ...

, and '' Skeemella'' of the

Wheeler Shale The Wheeler Shale (named by Charles Walcott) is a Cambrian ( 507 Ma) fossil locality world-famous for prolific agnostid and '' Elrathia kingii'' trilobite remains (even though many areas are barren of fossils) and represents a Konzen ...

Anatomy

''N. aldridgei'' is known from several incomplete fossils which suggest that, in life, it was a fairly large animal (when compared to other vetulicolians). The largest fossil is about 150 millimetres long, leading researchers to estimate that that individual was about 170 millimetres long. The exquisitely preserved fossils show that running the length inside the tail was a notochord, thereby demonstrating the animal's chordate affinities as being related to

tunicate A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time ...

s. The forebody, and overall form are similar to vetulicolids of

Vetulicolidae Vetulicolidae is an extinct family of Early Cambrian deuterostomes comprising two genera: '' Vetulicola'' and ''Ooedigera ''Ooedigera peeli'' is an extinct vetulicolian from the Early Cambrian of North Greenland. The front body was flatten ...

, though, its researchers do not have confidence to place ''N. aldridgei'' within either Vetulicolid families Vetulicolidae, or

Didazoonidae Didazoonidae is a family of Vetulicolian chordates containing the species ''Didazoon haoae'' and ''Pomatrum ventralis''. Their fossils are from the Maotianshan shales Cambrian Lagerstätte A Lagerstätte (, from ''Lager'' 'storage, lair' ' ...

Etymology

The genus name translates as "island swimmer" in reference to both its obvious adaptations for a

nekton Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms t ...

ic lifestyle in the water column, and the great distance between Kangaroo Island and China, the primary center of vetulicolian diversity, even during Cambrian times. The specific name commemorates the efforts and memory of Richard "Dick" Aldridge for his crucial research in resolving vetulicolian affinities.

References

{{Taxonbar, from=Q20712554 Vetulicolia Paleozoic animals of Australia Fossils of Australia Paleontology in South Australia Fossil taxa described in 2014