''Holoptychius'' (from el, όλος , 'whole' and el, πτυχή 'fold') 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
porolepiform
Porolepiformes is an Order (biology), order of prehistoric lobe-finned fish which lived during the Devonian geological period, period (about 416 to 359 million years ago). The group contains two family (biology), families: Holoptychiidae and Poro ...
lobe-finned fish from the
Middle Devonian to
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 ...
(
Mississippian) periods. It is known from fossils worldwide. The genus was first described by
Louis Agassiz
Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history.
Spending his early life in Switzerland, he rec ...
in 1839.
[
]
Description
''Holoptychius'' was a streamlined predator about long (though largest specimen could grew up to ), which fed on other bony fish
Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...
. Its rounded scales and body form indicate that it could have swum quickly through the water to catch prey. Similar to other rhipidistia
Rhipidistia, also known as Dipnotetrapodomorpha, is a clade of lobe-finned fishes which includes the tetrapods and lungfishes. Rhipidistia formerly referred to a subgroup of Sarcopterygii consisting of the Porolepiformes and Osteolepiformes, a d ...
ns, it had fang-like teeth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...
on its palate in addition to smaller teeth on the jaws. Its asymmetrical tail sported a caudal fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...
on its lower end. To compensate for the downward push caused by this fin placement, the pectoral fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...
s of ''Holoptychius'' were placed high on the body.
Species
Of the genus ''Holoptychius'' the following species have been described:[Species ''Holoptychius'']
/ref>
* ''H. americanus''
* ''H. andersoni''
* ''H. bergmanni'' (Downs et al, 2013) from the Frasnian
The Frasnian is one of two faunal stages in the Late Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Givetian Stage and followed by the Famennian Stage.
Major reef-building was under way during th ...
-aged Fram Formation
The Fram Formation is an Upper Devonian (Frasnian) sequence of rock strata on Ellesmere Island that came into prominence in 2006 with the discovery in its rocks of examples of the transitional fossil, ''Tiktaalik'', a sarcopterygian or lobe-finne ...
of Ellesmere Island
Ellesmere Island ( iu, script=Latn, Umingmak Nuna, lit=land of muskoxen; french: île d'Ellesmere) is Canada's northernmost and List of Canadian islands by area, third largest island, and the List of islands by area, tenth largest in the world. ...
, Arctic Canada[Downs, Jason P.; Daeschler, Edward B.; Jenkins, Farish A.; Shubin, Neil H. (2013-03).]
Holoptychius bergmannisp. nov. (Sarcopterygii, Porolepiformes) from the Upper Devonian of Nunavut, Canada, and a Review ofHoloptychiusTaxonomy
. Proceedings of the Academy of Natural Sciences of Philadelphia. 162 (1): 47–59. doi:10.1635/053.162.0104. ISSN 0097-3157.
* ''H. flemingi''
* ''H. giganteus''
* ''H. halli''
* ''H. hopkinsii''
* ''H. nobilissimus''
* ''H. quebecensis''
* ''H''. sp. indet. from the Kennebecasis Formation of New Brunswich, 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 ...
.
* ''H.'' sp. indet. from the Cuche Formation
The Cuche Formation ( es, Formación Cuche, Cc) is a geological formation of the Floresta Massif, Altiplano Cundiboyacense in the Eastern Ranges of the Colombian Andes. The sequence of siltstones, shales, and sandstone beds dates to the Late Devo ...
of Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
, known from an isolated tooth (UN-DG-PALV86) and preserved scales (UN-DG-PALV50-51).
Distribution
Fossils of ''Holoptychius'' have been found in the Mississippian of the United Kingdom and the Devonian of Belgium, Colombia (Cuche Formation
The Cuche Formation ( es, Formación Cuche, Cc) is a geological formation of the Floresta Massif, Altiplano Cundiboyacense in the Eastern Ranges of the Colombian Andes. The sequence of siltstones, shales, and sandstone beds dates to the Late Devo ...
, Boyacá),[Janvier & Villarroel, 1998] Norway, Canada, the Russian Federation, and the United States (Pennsylvania).[''Holoptychius'']
at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...
.org
Gallery
File:Holoptychius andersoni.jpg, ''H. andersoni''
File:Holoptychius sp. 2.jpg, Life restoration of ''Holoptychius'' sp.
File:Holoptychius nobilissimus.jpg, ''H. nobilissimus'' and scale
References
Bibliography
*
Porolepiformes
Late Devonian fish
Carboniferous fish
Devonian fish of Europe
Devonian fish of North America
Prehistoric fish of South America
Devonian animals of South America
Devonian Colombia
Fossils of Colombia
Fossil taxa described in 1839
Taxa named by Louis Agassiz
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