''Urosthenes'' 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 of prehistoric
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 ...
that lived during the
Lopingian (late
Permian) to
Middle Triassic epochs
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 ...
in what is now
New South Wales, Australia.
The
type species is ''U. australis'', described from Middle Triassic deposits. The second species, ''U. latus'', was found in Permian (
Wuchiapingian?) aged
rock layers
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...
and was first described in 1931 by
Arthur Smith Woodward, based on a specimen found in
Lithgow, New South Wales.
Appearance
''Urosthenes'' had a short and round body with large and veil-like fins almost symmetrical in shape. The
ventral fins were closer to the head and also were quite large compared to the body, and similarly the
dorsal and
anal 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 ...
s. Contrary to most other archaic
actinopterygians, ''Urosthenes'' had very thin scales.
See also
*
Prehistoric fish
*
List of prehistoric bony fish
A ''list'' is any set of items in a row. List or lists may also refer to:
People
* List (surname)
Organizations
* List College
Albert A. List College of Jewish Studies, known simply as List College, is the undergraduate school of the J ...
References
External links
Bony fish in the online Sepkoski Database
Palaeonisciformes
Permian Australia
Triassic Australia
Fossils of Australia
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