Triassic marine vertebrate apex predators

''Fadenia'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of eugeneodontid

holocephali Holocephali ("complete heads"), sometimes given the term Euchondrocephali, is a subclass of cartilaginous fish in the class Chondrichthyes. The earliest fossils are of teeth and come from the Devonian period. Little is known about these primiti ...

chondrichthyan Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. C ...

from the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

Period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

(

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

), the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

period of

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...

, and the

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a un ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

of Greenland and

Sulphur Mountain Formation The Sulphur Mountain Formation is a geologic formation of Early to Middle Triassic age. It is present on the western edge of the Western Canada Sedimentary Basin in the foothills and Rocky Mountains of western Alberta and northeastern British Col ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

Eugeneodontida The Eugeneodontida is an extinct and poorly known order of cartilaginous fishes. They possessed "tooth-whorls" on the symphysis of either the lower or both jaws and pectoral fins supported by long radials. They probably lacked pelvic fins and ana ...

are an extinct order of

Chondrichthyes Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. ...

. They are characterized by the presence of tooth whorls. They include iconic genera, such as ''

Helicoprion ''Helicoprion'' is an extinct genus of shark-like eugeneodont fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls", which in life were embedded in the lower jaw. As with most extin ...

'' (buzz-saw shark), '' Ornithoprion'', '' Edestus'' or '' Caseodus''. ''Fadenia'' is one of the few eugeneodontid genera that survived the end-Permian mass extinction event. It is one of the last surviving genera of this

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

. It could reach about in length. The first fossils of Fadenia were discovered and written about in the periodical

Meddelelser om Grønland ''Meddelelser om Grønland'' ("''Communications on Greenland''") is a Danish scientific periodical which publishes scientific results from all fields of research on Greenland. It was established by Frederik Johnstrup and published as a single ser ...

in 1932 by the Danish vertebrate palaeontologist Eigil Nielsen after studying the

Upper Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

beds of Cape Stosch, in the fjord of

Godthab Gulf Godthab Gulf ( da, Godthåb Golf), also known as Godthaab Golf, Clavering Fjord, Clavering Sound and Inner Bay, is a fjord in King Christian X Land, East Greenland. Administratively it is part of the Northeast Greenland National Park zone. History ...

King Christian X Land King Christian X Land ( da, Kong Christian X Land) is an area of northeastern Greenland. History This area was named after King Christian X of Denmark and Iceland (1870 – 1947), who rose to the throne in 1912. At the time of the Three-year ...

. He had joined at the beginning of the

Three-year Expedition to East Greenland The Three-year Expedition ( da, Treårsekspeditionen) was an exploratory expedition to East Greenland that lasted from 1931 to 1934 financed by the Carlsberg Foundation and the Danish state. The expedition included aerial surveys. Many geograph ...

led by Danish geologist and explorer

Lauge Koch Lauge Koch (5 July 1892 – 5 June 1964) was a Danish geologist and Arctic explorer. Biography Lauge Koch was born in 1892 to Karl and Elisabeth Koch. His development as a scientist was greatly influenced by his father's second cousin Johan Pet ...

. The manager of the expedition was the botanist

Gunnar Seidenfaden Gunnar Seidenfaden (1908 – February 9, 2001) was a Danish diplomat and botanist. He was Danish ambassador in Thailand 1955–1959, and in the U.S.S.R. 1959–1961. He was an expert on Southeast Asia Orchidaceae. He published several multi-volum ...

, after whose surname the taxon was named.

References

Further reading