''Banffia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

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 ...

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 preserved ...

s. The genus commemorates

Banff, Alberta Banff is a town within Banff National Park in Alberta, Canada. It is located in Alberta's Rockies along the Trans-Canada Highway, approximately west of Calgary and east of Lake Louise. At above Banff is the community with the second highest ...

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

taxa In biology, a taxon ( back-formation from '' taxonomy''; plural 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 n ...

is controversial. It is considered to be a member of the enigmatic phylum

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 ...

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 und ...

-like un-mineralized shells that are fused together. A crown-like structure formed of three concentric circular features surrounds the mouth. An

antenna Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two collid ...

-form structure just posterior to the mouth may be a sensory organ. The posterior section is composed of 40 to 50 segments. The

gut Gut or guts may refer to: Anatomy * Abdomen or belly, the region of a vertebrate between the chest and pelvis * Abdominal obesity or "a gut", a large deposit of belly fat * Gastrointestinal tract or gut, the system of digestive organs * Ins ...

is straight, and the

anus The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, d ...

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'' were probably

filter Filter, filtering or filters may refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Filter (software), a computer program to process a data stream * Filter (video), a software component tha ...

or deposit feeders.

Classification

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

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

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

Arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

a, or

Urochordata 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 ca ...

. 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 respiratory organ that many 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 respiration on land provided they ar ...

s and an

endostyle The endostyle is an anatomical feature found in invertebrate chordates and larval lampreys. It is an organ which assists chordates in filter-feeding. It is found in adult urochordates and cephalochordates, as well as in the larvae of the ve ...

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

deuterostome Deuterostomia (; in Greek) are animals typically characterized by their anus forming before their mouth during embryonic development. The group's sister clade is Protostomia, animals whose digestive tract development is more varied. Some exa ...

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 In anatomy, the notochord is a flexible rod which is similar in structure to the stiffer cartilage. If a species has a notochord at any stage of its life cycle (along with 4 other features), it is, by definition, a chordate. The notochord cons ...

, making ''Banffia'' and their relatives

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 five ...

s, possibly the sister group 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 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 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

* Vetulicolia Cambrian animals of North America Prehistoric animal genera Paleozoic life of British Columbia Burgess Shale animals {{paleo-deuterostome-stub Cambrian genus extinctions