Asaphus

{{Short description|Extinct genus of trilobites}} {{distinguish|Asaphes}} {{Automatic taxobox | fossil_range = {{Geological range|475|458|upper Floian to Darriwilian}} | image = Asaphus latus frontal.jpg | image_caption = ''A. latus'' | taxon = Asaphus | authority = Brongniart, 1822<ref name="Brongiart, 1822" /> | subdivision_ranks = Species | subdivision = *see text | type_species=''Entomostracites expansus''<ref name="Jaanusson, 1956"/> | type_species_authority=Wahlenberg, [1818]<ref name="Wahlenberg, 1818" /> }}

'''''Asaphus''''' ({{IPA|/ˈæsæfʌs/}}) is a genus of trilobites that is known from the Lower (upper Arenig) and Middle Ordovician of northwestern Europe (Sweden, Estonia, Saint Petersburg Area).<ref>{{cite journal |author=Martin Stein & Jan Bergström |year=2010 |title=Some lower Middle Ordovician species of ''Asaphus'' (Trilobita) from Sweden |journal=GFF |volume=132 |issue=2 |pages=105–116 |doi=10.1080/11035897.2010.486478|bibcode=2010GFF...132..105S |s2cid=129705036 }}</ref>

== Etymology == The generic name is derived from the Greek word ''asaphes'', meaning "indistinct."

== Description == thumb|left|''A. plautini'', enrolledThe headshield (or cephalon) and tailshield (or pygidium) are semicircular and without a border (defined by a furrow or a change in convexity parallel to its margin). The cephalon is of approximately equal size as the pygidium (or isopygous). The central raised area of the cephalon (or glabella) is long, reaching the frontal margin. It may have faint lateral glabellar furrows or be smooth, and sometimes an inconspicuous tubercle is present just in front of the hardly discernible occipital ring. The natural fracture lines (sutures) of the head run along the top edges of the compound eye. From the back of the eye these cut to the back of the head (or is said to be opisthoparian) and not to the side. The free cheeks (or librigenae) are separated from each other anteriorly by a suture at the midline. The corner between the side and the back of the cephalon (or genal angle) is rounded or (in a few species) pointed into spines. Eyes holochroal, commonly more or less conical, short or moderate in length. In some evolution lines, the visual surface of the eye is raised on a stalk.

The lateral corners of the palate (or hypostome), visual from the ventral side, are more or less protruding, and the posterior part is forked with two triangular teeth. The reflexed margin of the exoskeleton (or doublure) is broad. The articulate midlength part of the body (or thorax) consists of 8 segments. Furrows in the parts outside the axis (or pleural furrows) are diagonal. The pygidium is rounded, and has a long axis with concave, posteriorly parallel sides. Some rings may be faintly defined anteriorly and the axis dissolves in the postaxial field. The areas outside the axis (or pleural fields) are smooth or very faintly ribbed.<ref name=Treatise334>{{cite book|last= Moore|first= R.C.|year= 1959|title= Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha|publisher= Geological Society of America/University of Kansas Press|series= Treatise on Invertebrate Paleontology|volume= Part O.|pages= O334–O436|location= Boulder, Colorado/Lawrence, Kansas|isbn= 978-0-8137-3015-8}}</ref>

==Species== {{More citations needed section|date=September 2017}}

[[File:Asaphus kowalewskii lateral overlapeyes.jpg|thumb|right|''A. kowalewskii'']] {{div col|colwidth=30em}} * ''A. expansus'' (Wahlenberg, [1818])<ref>{{cite journal|author= International Commission on Zoological Nomenclature|year= 1982|title= Direction 111 - ''Entomostracites punctatus'' Wahlenberg (Trilobita) (Official List Of Specific Names No. 1595): Date To Be Cited As [1818]|journal= Bulletin of Zoological Nomenclature|volume= 39|url= http://biostor.org/reference/76324}}</ref> (type species) synonyms ''Entomostracites expansus'', ''Entomolithus paradoxus α expansus'' * ''A. acuminatus'' Boeck, 1838 * ''A. bottnicus'' Jaanusson * ''A. broeggeri'' Schmidt, 1898 * ''A. cornutus'' Pander, 1830 * ''A. eichwaldi'' Schmidt * ''A. heckeri'' (Ivantsov) * ''A. holmi'' Schmidt, 1898 * ''A. ingrianus'' Jaanusson, 1953 * ''A. intermedius'' Lessnikova in Balashova, 1953 * ''A. knyrkoi'' Schmidt * ''A. kotlukovi'' Lessnikova in Balashova, 1953 * ''A. kowalewskii'' Lawrow, 1856 * ''A. latus'' Pander, 1830 * ''A. laevissimus'' Schmidt, 1898 * ''A. lepidurus'' Neiszkowski, 1859 * ''A. minor'' * ''A. neiszkowskii'' Schmidt, 1898 * ''A. pachyophthalmus'' * ''A. platycephalus'' (Stokes, 1824) <ref>{{cite book |url=https://archive.org/details/texanpermianand00whitgoog |quote=charles stokes fossil. |page=[https://archive.org/details/texanpermianand00whitgoog/page/n32 28] |title=The Texan Permian and Its Mesozoic Types of Fossils |first=Charles Abiathar |last=White |author-link=Charles Abiathar White |year=1891 |publisher=United States Geological Survey |access-date=26 April 2018}}</ref> * ''A. plautini'' Schmidt, 1898 * ''A. punctatus'' Lessnikova, 1949 * ''A. raniceps'' Dalman, 1827 * ''A. robustus'' * ''A. sulvevi'' Jaanusson * ''A. vicarius'' (Toernquist, 1884) * ''A. wahlenbergi'' {{div col end}}

===Species previously assigned to ''Asaphus'' === thumb|right|''A. expansus'' showing the broad doublure and the forked hypostomeAs the genus ''Asaphus'' was established early, many species have since been reassigned to genera in various trilobite orders.<ref name=Treatise446>{{cite book|last= Moore|first= R.C.|year= 1959|title= Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha|publisher= Geological Society of America/University of Kansas Press|series= Treatise on Invertebrate Paleontology|volume= Part O.|pages= O446 and O468|location= Boulder, Colorado/Lawrence, Kansas|isbn= 978-0-8137-3015-8}}</ref> {{div col|colwidth=30em}} * ''A. angustifrons'' = ''Ptychopyge angustifrons'' * ''A. armadillo'' = ''Nileus armadillo'' * ''A. aspectans'' = ''Coronura aspectans'' * ''A. barrandei'' = ''Basilicus barrandei'' * ''A. brongniarti'' = ''Eohomalonotus brongniarti'' * ''A. canadensis'' = ''Pseudogygites canadensis'' * ''A. cawdori'' = ''Acaste cawdori'' * ''A. corndensis'' = ''Ogyginus corndensis'' * ''A. debuchii'' = ''Ogygiocarella debuchii'' * ''A. devexus'' = ''Xenasaphus devexus'' * ''A. duplicatus'' = ''Platycalymene duplicatus'' * ''A. eichwaldi'' = ''Bollandia eichwaldi''<ref name='Osmólska'>{{cite journal|last= Osmólska|first= H.|year= 1970|title= Revision of non-cyrtosymbolinid trilobites from the Tournaisian-Namurian of Eurasia|journal= Palaeontologia Polonica|volume= 23}}</ref> * ''A. extans'' = ''Bathyurus extans'' * ''A. fischeri'' = ''Pliomera fischeri'' * ''A. frontalis'' = ''Niobe frontalis'' * ''A. gemmuliferus'' = ''Phillipsia gemmulifera''<ref name='Osmólska'/> * ''A. globiceps'' = ''Bollandia globiceps''<ref name='Osmólska'/> * ''A. granuliferus'' = ''Bollandia globiceps''<ref name='Osmólska'/> * ''A. hausmanni'' = ''Odontochile hausmanni'' * ''A. homfrayi'' = ''Asaphellus homfrayi'' * ''A. latifrons'' = ''Stygina latifrons'' * ''A. nasutus'' = ''Neoprobolium nasutus'' * ''A. obsoletus'' = ''Bollandia obsoleta''<ref name='Osmólska'/> * ''A. palpebrosus'' = ''Symphysurus palpebrosus'' * ''A. plicicostis'' = ''Plectasaphus plicicostis'' * ''A. praetextus'' = ''Ogmasaphus praetextus'' * ''A. selenourus'' = ''Odontocephalus selenourus'' * ''A. seminiferus'' = ''Eocyphinium seminiferum''<ref name='Osmólska'/> * ''A. seticornis'' = ''Tretaspis seticornis'' * ''A. stacyi'' = ''Homalopyge stacyi'' * ''A. stokesii'' = ''Warburgella stokesii'' * ''A. subcaudatus'' = ''Acaste subcaudata'' * ''A. truncatulus'' = ''Phillipsia truncatula''<ref name='Osmólska'/> * ''A. tyrannus'' = ''Basilicus tyrannus'' {{div col end}}

== References == {{Reflist|30em|refs= <ref name="Brongiart, 1822">{{cite book|last1=Brongiart|first1=Alexandre|editor1-last=Brongniart|editor1-first=Alexandre|editor2-last=Desmarest|editor2-first=Anselme-Gaëtan|title=Histoire naturelle des crustacés fossiles|date=1822|publisher=L.-T. Cellot|location=Paris|pages=17–25|chapter-url=https://www.biodiversitylibrary.org/page/9656469|chapter=Des corps organisés fossiles nommés trilobites}}</ref>

<ref name="Jaanusson, 1956">{{cite journal|last1=Jaanusson|first1=Valdar|title=Proposed use of the Plenary Powers to suppress the generic name ''Asaphus'' as published by Brongniart in Desmarest, 1817, and to designate a type species in harmony with general usage for the genus ''Asaphus'' Brongniart, 1822 (Class Trilobita)|journal=The Bulletin of Zoological Nomenclature|date=1956|volume=12|issue=3|pages=90–96|url=https://www.biodiversitylibrary.org/part/36409}}</ref>

<ref name="Wahlenberg, 1818">{{cite journal|last1=Wahlenberg|first1=Georgio|title=Petrificata telluris svecanae|journal=Nova Acta Regiae Societatis Scientiarum Upsaliensis|date=1821|volume=8|pages=25–27|url=https://www.biodiversitylibrary.org/page/2560249|orig-year=1818}}</ref> }}

== External links == *{{Wikispecies-inline|Asaphus|''Asaphus''}} * [https://web.archive.org/web/20140103232456/http://www.macroevolution.narod.ru/ivantsov/ivantsov.htm drawings of many ''Asaphus'' species] * [https://web.archive.org/web/20120414161230/http://www.paleoart.com/catalog/332/cornutus Website of the Saint-Petersburg Paleontological Laboratory] * [http://www.fossilmuseum.net/Fossil_Sites/trilobites-russia/Russian_Trilobites.htm Schematic of the relationships between the different species]

Category:Asaphida genera Category:Ordovician trilobites of Europe Category:Fossils of Estonia Category:Fossils of Russia Category:Fossils of Sweden Category:Early Ordovician first appearances Category:Middle Ordovician extinctions Category:Taxa named by Alexandre Brongniart Category:Floian Category:Dapingian Category:Darriwilian Category:Fossil taxa described in 1822 Category:Asaphidae