''Banffia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of animals described from

Middle Cambrian Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek (di ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s. The genus commemorates

Banff, Alberta Banff is a resort town in Banff National Park, Alberta, Canada, in Alberta's Rockies along the Trans-Canada Highway, west of Calgary, east of Lake Louise, Alberta, Lake Louise, and above Banff was the first municipality to incorporate within ...

, near where the first fossil specimens were discovered. Its placement in higher

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

is controversial, with it mostly being considered to be a member of the enigmatic phylum

Vetulicolia Vetulicolia is a group of bilaterian marine animals encompassing several extinct species from the Cambrian, and possibly Ediacaran, periods. As of 2023, the majority of workers favor placing Vetulicolians in the stem group of the Chordata, but ...

Anatomy

''Banffia constricta'' is known from hundreds of fossils found in 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 fos ...

s. It is up to 10 cm in length, and divided equally into anterior and posterior parts. The entire body is twisted in a clockwise spiral, as seen from the front. This is believed to be a secondary adaptation from an initial

bilateral Bilateral may refer to any concept including two sides, in particular: *Bilateria, bilateral animals *Bilateralism, the political and cultural relations between two states *Bilateral, occurring on both sides of an organism ( Anatomical terms of l ...

condition for a burrowing lifestyle. The anterior section is covered by two

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

-like un-mineralized shells that are fused together. A crown-like structure formed of three concentric circular features surrounds the mouth. An antenna-form structure just posterior to the mouth may be a sensory organ. The posterior section is composed of 40 to 50 segments. The gut is straight, and the

anus In mammals, invertebrates and most fish, the anus (: anuses or ani; from Latin, 'ring' or 'circle') is the external body orifice at the ''exit'' end of the digestive tract (bowel), i.e. the opposite end from the mouth. Its function is to facil ...

is at the terminal tip of the posterior section. The gut appears to have a series of

diverticula In medicine or biology, a diverticulum is an outpouching of a hollow (or a fluid-filled) structure in the body. Depending upon which layers of the structure are involved, diverticula are described as being either true or false. In medicine, t ...

or pouches. A possible circulatory system is visible in the fossils. ''B. constricta'' and its relative ''

Skeemella ''Skeemella'' is a genus of elongate animal from the Middle Cambrian Wheeler Shale and Marjum lagerstätte of Utah. It has been classified with the banffozoan vetulicolians. Description ''Skeemella'', which was first described in 2005, is d ...

'' were probably

filter Filtration is a physical process that separates solid matter and fluid from a mixture. Filter, filtering, filters or filtration may also refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Fil ...

or deposit feeders.

Classification

There is no agreement on the classification of ''Banffia''. ''B. constricta'' was assigned to the

annelid The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to vario ...

s by Walcott in 1911. As of 2006, different proposals would place ''Banffia'' in

Arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

a, or

Urochordata Tunicates are marine invertebrates belonging to the subphylum Tunicata ( ). This grouping 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 ...

. While the body plan (equal anterior and posterior sections with segmentation) resembles that of the Vetulicolians, it is argued that the absence of

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

s and an

endostyle The endostyle is an organ found in invertebrate chordate species of tunicates, lancelets, and in the larval stage of vertebrate lampreys. It assists in filter-feeding. It has evolved into the thyroid in vertebrate chordates. Since the endo ...

, and the presence of gut diverticula makes ''Banffia'' unlikely to be a member of the

deuterostome Deuterostomes (from Greek: ) are bilaterian animals of the superphylum Deuterostomia (), typically characterized by their anus forming before the mouth during embryonic development. Deuterostomia comprises three phyla: Chordata, Echinodermata, ...

s. However, an apparent complete lack of appendages (aside from the antenna-like structures) makes ''B. constrictas placement within Arthropoda equally unlikely. More recent finds of similarly shaped animals show structures thought to be a

notochord The notochord is an elastic, rod-like structure found in chordates. In vertebrates the notochord is an embryonic structure that disintegrates, as the vertebrae develop, to become the nucleus pulposus in the intervertebral discs of the verteb ...

, making ''Banffia'' and their relatives

chordate A chordate ( ) is a bilaterian animal belonging to the phylum Chordata ( ). All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics ( synapomorphies) that distinguish them from ot ...

s, possibly the sister group to

tunicate Tunicates are marine invertebrates belonging to the subphylum Tunicata ( ). This grouping 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 species ''Banffia confusa'', known from fossils from the Chengjiang shales, was originally assigned to this genus, though, recent research shows that this species is not closely related to ''B. constricta'', having been renamed as its junior synonym, ''

Heteromorphus ''Heteromorphus'' is an extinct genus of banffiid from the lower Cambrian Chengjiang lagerstatte. It contains one broadly accepted species, ''Heteromorphus confusus'', as well as a proposed junior synonym, ''Heteromorphus longicaudatus'' that ...

longicaudatus'', and placed in a different class altogether, "Heteromorphida." Later, Aldridge, et al. resurrected ''B. confusa'' as ''Heteromorphus confusus'', noting a variety of anatomical differences among the various specimens of ''Heteromorphus'', suggesting that there may be more species recognized with more fossils discovered.

References

External links

* {{Taxonbar, from=Q923755 Vetulicolia Cambrian animals of North America Prehistoric animal genera Paleozoic life of British Columbia Burgess Shale animals Cambrian genus extinctions