''Pambikalbae'' is a

monospecific In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

genus known from the

Ediacaran The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last ...

Period (approximately 555 million years ago) of South Australia. Its morphology resembles the morphology of colonial

cnidaria Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...

ns, such as

sea pen Sea pens are marine cnidarians belonging to the superfamily Pennatuloidea, which are colony-forming benthic filter feeders within the order Scleralcyonacea. There are 14 families within the order and 35 extant genera, and it is estimated a ...

s or

siphonophore Siphonophorae (from Ancient Greek σίφων (siphōn), meaning "tube" and -φόρος (-phóros), meaning "bearing") is an order within Hydrozoa, a class of marine organisms within the phylum Cnidaria. According to the World Register of Marine ...

Description

''Pambikalbae'' had a broad,

frondose Frondosity (from Latin ''frondōsus'' meaning 'leafy') is the property of an organism that normally flourishes with fronds or leaf-like structures. Many frondose organisms are thalloid and lack the organization of tissues into organs, with the ...

-shaped body composed of multiple vanes extending from an axial stem, and containing a serial series of chambers. Specimens of ''Pambikalbae'' found thus far have measured approximately 20 to 30 cm in length, with a width of 12 cm at the widest point of the frondose-body, and 6.6 cm wide at the stem.

Diversity

''Pambikalbae'' is a monospecific genus, with only one known species, ''Pambikalbae hasenohrae''.

Discovery

''Pambikalbae hasenohrae'' was discovered within a fossiliferous exposure on the Nilpena pastoral property in the Flinders Ranges in South Australia. Pamela Hasenohr, an amateur geologist, found and brought the ''Pambikalbae'' fossils to the attention of Richard Jenkins, a research associate of the

South Australian Museum The South Australian Museum is a natural history museum and research institution in Adelaide, South Australia, founded in 1856 and owned by the Government of South Australia. It occupies a complex of buildings on North Terrace in the cultur ...

. Richard Jenkins and his associate Chris Nedin collected five ''Pambikalbae'' specimens from this exposure, and published their description of the genus in 2007. In this publication, they named the type species of the genus, ''P. hasenohrae,'' after Pamela Hasenohr.The name of the genus is a combination of parnkalla words "Pambi(meaning small bag or purse, in reference to the chamber like structure)" and "Kalbi(meaning leaf)".

Distribution

''Pambikalbae hasenohrae'' specimens have been found preserved in channel sandstones on the Nilpena pastoral property in the Flinders Ranges of South Australia. These sandstones occur directly below the Ediacaran Member of the Rawnsley Quartzite, a stratigraphic layer rich with Ediacaran fossils that was deposited during cycles of marine transgression.

Taphonomy

''Pambikalbae hasenohrae'' fossils consist of both surface molds and internal casts. It is likely that the hollow chambers of these specimens were partly filled with sediments before their entire bodies were buried, preventing the bodies from being entirely flattened during burial and preserving the three-dimensional structure of both the internal and external parts of the original organisms. The lithified sands that occupy the once hollow parts of the specimens exhibit fine laminations and small scale crossbedding, which indicates that the specimens were buried progressively, not instantly. This gradual burial may have created enough time for currents to carry sediments into the internal chambers before the entire organism was buried.

Ecology

''Pambikalbae'' was likely a benthic, sessile, heterotrophic marine suspension feeder. The chambers of ''Pambikalbae'' were open to the external environment, allowing water to enter and exit freely. These chambers were likely lined with flagellate cells or cilia, which would capture detrital food particles suspended in the water.

References

{{Taxonbar, from=Q49002437 Ediacaran life Siphonophorae Monotypic prehistoric cnidarian genera Petalonamae