''Rhyncholepis'' was an
extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
genus of
anaspid from the Late
Silurian
The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...
.
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
s of species ''R. butriangula'' and ''R. parvula'' have been found in
Ringerike, Norway
Ringerike is a municipality in Buskerud county, Norway. It is part of the traditional region
A tradition is a system of beliefs or behaviors (folk custom) passed down within a group of people or society with symbolic meaning or special signi ...
, and
Oesel, Estonia.
The
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
has two species, described in 1911 and 2002.
Discovery
''Rhyncholepis parvula'' was discovered and originally described in 1911, and described in more detail in 1924 by Norwegian Professor Johan Kiær. In the associated monograph, Kiær describes the genus in great detail, along with several other anaspids discovered around the same time.
More recently, the second discovered species (''R. butriangula'') was described by Henning Blom, Tiiu Märss, and C. Giles Miller in 2002.
References
Birkeniiformes
Silurian jawless fish
Fossils of Norway
Fossil taxa described in 1911
Birkeniiformes genera
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