Banffia is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of animals described from Middle Cambrian fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s. The genus commemorates Banff, Alberta

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....

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

Taxon

|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

 is controversial.

Anatomy

Banffia constricta is known from hundreds of fossils found in the Burgess Shale

Burgess Shale

The Burgess Shale Formation, located in the Canadian Rockies of British Columbia, is one of the world's most celebrated fossil fields, and the best of its kind. It is famous for the exceptional preservation of the soft parts of its fossils...

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

Symmetry (biology)

Symmetry in biology is the balanced distribution of duplicate body parts or shapes. The body plans of most multicellular organisms exhibit some form of symmetry, either radial symmetry or bilateral symmetry or "spherical symmetry". A small minority exhibit no symmetry .In nature and biology,...

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

Carapace

A carapace is a dorsal 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 underside is called the plastron.-Crustaceans:In crustaceans, the...

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

Antenna (biology)

Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....

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

Gastrointestinal tract

The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....

 is straight, and the anus

Anus

The anus 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, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...

 is at the terminal tip of the posterior section. The gut appears to have a series of diverticula or pouches. A possible circulatory system is visible in the fossils. B. constricta and its relative Skeemella

Skeemella

Skeemella clavula is an elongate animal from what is now the Middle Cambrian Wheeler Shale lagerstatten, of Utah....

 were probably filter

Filter feeder

Filter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish and some sharks. Some birds,...

 or deposit feeders.

Classification

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

Annelid

The annelids , formally called Annelida , are a large phylum of segmented worms, with over 17,000 modern species including ragworms, earthworms and leeches...

s by Walcott

Charles Doolittle Walcott

Charles Doolittle Walcott was an American invertebrate paleontologist. He became known for his discovery in 1909 of well-preserved fossils in the Burgess Shale of British Columbia, Canada.-Early life:...

 in 1911. As of 2006, different proposals would place Banffia in Urochordata

Tunicate

Tunicates, also known as urochordates, are members of the subphylum Tunicata, previously known as Urochordata, a group of underwater saclike filter feeders with incurrent and excurrent siphons that is classified within the phylum Chordata. While most tunicates live on the ocean floor, others such...

, Vetulicolia

Vetulicolia

VetulicoliaThe phylum name, Vetulocolia, is derived from the type genus, Vetulicola, which is a compound Latin word composed of vetuli, or "old," and cola, or "inhabitant." is an extinct phylum encompassing several Cambrian organisms...

 or Arthropod

Arthropod

An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

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

Gill

A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

s and an endostyle

Endostyle

An endostyle is a longitudinal ciliated groove on the ventral wall of the pharynx which produces mucus to gather food particles. It is found in urochordates and cephalochordates, and in the larvae of lampreys. It aids in transporting food to the esophagus. It is also called the hypopharyngeal groove...

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

Deuterostome

Deuterostomes are a superphylum of animals. They are a subtaxon of the Bilateria branch of the subregnum Eumetazoa, and are opposed to the protostomes...

s. However, an apparent complete lack of appendages (aside from the antenna-like structures) makes B. constrictas placement within Arthropoda equally unlikely.

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.