''Haootia quadriformis'' is an

extinct animal This page features lists of extinct species, organisms that have become Extinction, extinct, either in the wild or completely disappeared from Earth. In actual theoretical practice, a species not definitely located in the wild in the last fifty ...

belonging to the

Ediacaran biota The Ediacaran (; formerly Vendian) biota is a Taxonomy (biology), taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period (). These were composed of enigmatic tubular and frond-sh ...

. Estimated to be about 560 million years old, ''H. quadriformis'' is identified as a

cnidaria Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter. Their distinguishing feature is cnidocytes, specialized cells that th ...

n polyp, and represents the earliest known evidence for

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...

tissue in an animal. Discovered in 2008 from

Newfoundland Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

in eastern Canada, it was formally described in 2014. It is the first Ediacaran organism discovered to show fossils of muscle fibres. Structural examination of the muscles and morphology indicate that the animal is a cnidarian, though, which

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...

''H. quadriformis'' belongs to is currently undetermined.

Discovery and name

The first fossil of ''Haootia'' was discovered from lower

Fermeuse Formation The Fermeuse Formation is a fossil-bearing Ediacaran Formation (geology), geologic formation in Newfoundland. Palaeobiological community On Avalon Peninsula there is low diversity, and includes rare trace fossils, ''Palaeopascichnus'', and ''A ...

of Back Cove,

Bonavista Peninsula The Bonavista Peninsula is a large peninsula on the east coast of the island of Newfoundland in the Canadian province of Newfoundland and Labrador. It consists of 50 incorporated towns/unincorporated communities which have a population of 12,176 ...

in Newfoundland. It was originally unearthed by Martin D. Brasier of the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

in 2008. However, the specimen was not allowed to be removed according to provincial law in Newfoundland, so that only a

plaster cast A plaster cast is a copy made in plaster of another 3-dimensional form. The original from which the cast is taken may be a sculpture, building, a face, a pregnant belly, a fossil or other remains such as fresh or fossilised footprints – p ...

was made. The cast (plastotype) is maintained in the collections of the

Oxford University Museum of Natural History The Oxford University Museum of Natural History, sometimes known simply as the Oxford University Museum or OUMNH, is a museum displaying many of the University of Oxford's natural history specimens, located on Parks Road in Oxford, England. It a ...

. The actual fossil specimen, or

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, remains on the north shore of Back Cove, roughly 1.8 km NNW of Melrose town. A second, incomplete specimen was also discovered in the Trepassey Formation of Burnt Point, Bonavista Peninsula. The generic name ''Haootia'' is derived from the

Beothuk The Beothuk ( or ; also spelled Beothuck) were a group of indigenous people who lived on the island of Newfoundland. Beginning around AD 1500, the Beothuk culture formed. This appeared to be the most recent cultural manifestation of peoples w ...

word ''Haoot'', meaning "

demon A demon is a malevolent supernatural entity. Historically, belief in demons, or stories about demons, occurs in religion, occultism, literature, fiction, mythology, and folklore; as well as in media such as comics, video games, movies, ani ...

," to signify the striking appearance of the holotype. The specific name ''quadriformis'' is said to be derived from Latin ''quadri'', meaning "fourfold", and ''formis'', for "form", relating to the quadrilateral symmetry of the body. The proper word in classical Latin for "fourfold" is actually ''quadruplex'',Lewis, C.T. & Short, C. (1879). ''A Latin dictionary founded on Andrews' edition of Freund's Latin dictionary.'' Oxford: Clarendon Press. while ''forma'' is the proper word in classical Latin for "form".

Description

''Haootia quadriformis'' is uniquely different from any other Ediacaran fossil so far discovered in that it consists of bundles of fibres that have been identified as muscles. The entire body is in a broadly four-fold symmetrical arrangement. Thus the overall body organisation conforms to the key features of modern

cnidarians Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter. Their distinguishing feature is cnidocytes, specialized cells that th ...

. The fossil measures 56×37 mm in diameter. It indicates it is a soft-bodied animal having an appearance of a smooth discoidal structure connected by a relatively short stem to a quadrate body comprising numerous and regularly aligned linear fibres. The fibres, which are similar in pattern to parallelly arranged

muscle fibres A muscle cell is also known as a myocyte when referring to either a cardiac muscle cell (cardiomyocyte), or a smooth muscle cell as these are both small cells. A skeletal muscle cell is long and threadlike with many nuclei and is called a muscl ...

, extend laterally across the body, linking adjacent corners. The fibres extend beyond each corner to form an elongate branch, which is divided into smaller dichotomous branches. Smaller branches also arise from the lateral margins of the quadrate body, and also form dichotomously branched fibres.

References

External links

560-Million-Year-Old Fossil Provides Earliest Evidence of MusclesNewfoundland fossil is earliest evidence of muscled animals
{{Taxonbar, from=Q18164962 Prehistoric cnidarian genera Ediacaran life Ediacaran Newfoundland and Labrador Fossils of Canada Prehistoric animal enigmatic taxa Fossil taxa described in 2014 Paleontology in Newfoundland and Labrador

Discovery and name

Description

See also

References

External links