''Haootia quadriformis'' is an extinct animal belonging to the

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

. 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 invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...

n polyp, and represents the earliest known evidence for

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

tissue in an animal. Discovered in 2008 from

Newfoundland Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the population ...

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, Classes, 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 d ...

''H. quadriformis'' belongs to was undetermined until a 2024 study found it to be a staurozoan.

Discovery and name

The first fossil of ''Haootia'' was discovered from lower Fermeuse Formation 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 The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...

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 – ...

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 (OUMNH) is a museum displaying many of the University of Oxford's natural history specimens, located on Parks Road in Oxford, England. It also contains a lecture theatre which is used by the univers ...

. The actual fossil specimen, or

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

, remains on the north shore of Back Cove, roughly north-northwest 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 peoples in Canada, Indigenous people of Canada who lived on the island of Newfoundland (island), Newfoundland. The Beothuk culture formed around 1500 CE. This may have been ...

word , meaning '

demon A demon is a malevolent supernatural entity. Historically, belief in demons, or stories about demons, occurs in folklore, mythology, religion, occultism, and literature; these beliefs are reflected in Media (communication), media including f ...

', to signify the striking appearance of the holotype. The specific name ''quadriformis'' is said to be derived from Latin , meaning 'fourfold', and , for 'form', relating to the quadrilateral symmetry of the body. The proper word in classical Latin for 'fourfold' is actually ,Lewis, C.T. & Short, C. (1879). ''A Latin dictionary founded on Andrews' edition of Freund's Latin dictionary.'' Oxford: Clarendon Press. while 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 invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...

. 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, 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, from2=Q129553420 Monotypic prehistoric cnidarian genera Ediacaran life Ediacaran Newfoundland and Labrador Fossils of Canada Fossil taxa described in 2014 Paleontology in Newfoundland and Labrador

Discovery and name

Description

See also

References

External links