View source for Tanazios

{{Short description|Extinct genus of arthropods}}
{{Speciesbox
| fossil_range = {{fossil range|Homerian}}
| image =
| image_upright =
| image_caption =
| genus = Tanazios
| parent_authority = Siveter et al, 2007
| species = dokeron
| authority = Siveter et al, 2007
}}
'''''Tanazios''''' is a genus of [[Silurian]] stem-[[mandibulate]].
== Description ==
''Tanazios'' has a head with five pairs of appendages, these being the antennae, antennules, mandibles with gnathobasic coxae and two [[biramous]] limb pairs similar to those of the trunk, with a large projection in the [[hypostome]]'s centre. The trunk consists of 64 segments and has 60 appendage pairs, with a small telson on the end that holds the anus and a [[caudal ramus]].<ref name="Siveter et al">{{cite journal |last1=Siveter |first1=Derek J |title=A new probable stem lineage crustacean with three-dimensionally preserved soft parts from the Herefordshire (Silurian) Lagerstätte, UK |journal=The Royal Society Publishing |date=3 July 2007 |doi=10.1098/rspb.2007.0429 |url=https://royalsocietypublishing.org/doi/10.1098/rspb.2007.0429|pmc=2706188 }}</ref> ''Tanazios'' lacks second antennae, which character shared with [[Hexapoda|hexapods]].<ref>{{Cite journal |last=Budd |first=Graham E. |last2=Telford |first2=Maximilian J. |date=2009 |title=The origin and evolution of arthropods |url=https://www.nature.com/articles/nature07890 |journal=Nature |language=en |volume=457 |issue=7231 |pages=812–817 |doi=10.1038/nature07890 |issn=1476-4687}}</ref>
== Ecology ==
''Tanazios'' has been proposed to be either a benthic or [[demersal]] scavenger.<ref name="Siveter et al">{{cite journal |last1=Siveter |first1=Derek J |title=A new probable stem lineage crustacean with three-dimensionally preserved soft parts from the Herefordshire (Silurian) Lagerstätte, UK |journal=The Royal Society Publishing |date=3 July 2007 |doi=10.1098/rspb.2007.0429 |url=https://royalsocietypublishing.org/doi/10.1098/rspb.2007.0429|pmc=2706188 }}</ref>
== Etymology ==
''Tanazios'' is a combination of the words "tanaos", meaning "long", "zoon", meaning "animal" and "pelagios", meaning "of the sea". The species name ''dokeron'' is a combination of "dodeka" ("twelve"), "kerouchos" ("horned") and "epikranon" ("helmet").
== Distribution ==
''Tanazios'' is known from two reconstructed specimens from the [[Coalbrookdale Formation]] (as the concretions fossils are found in cannot be studied easily, fossils have to be reconstructed digitally via grinding then scanning them).
== Classification ==
''Tanazios'' was originally considered as stem-group [[crustacean]].<ref>{{Cite journal |last=Siveter |first=David J. |last2=Briggs |first2=Derek E. G. |last3=Siveter |first3=Derek J. |last4=Sutton |first4=Mark D. |last5=Legg |first5=David |date=2017-03-29 |title=A new crustacean from the Herefordshire (Silurian) Lagerstätte, UK, and its significance in malacostracan evolution |url=https://royalsocietypublishing.org/doi/10.1098/rspb.2017.0279 |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=284 |issue=1851 |pages=20170279 |doi=10.1098/rspb.2017.0279 |issn=0962-8452 |pmc=5378094 |pmid=28330926}}</ref> According to phylogenic analysis in Pulsipher ''et al.'' (2022), it is considered as stem-mandibulate instead.<ref name=":0">{{Cite journal |last1=Pulsipher |first1=M. A. |last2=Anderson |first2=E. P. |last3=Wright |first3=L. S. |last4=Kluessendorf |first4=J. |last5=Mikulic |first5=D. G. |last6=Schiffbauer |first6=J. D. |year=2022 |title=Description of ''Acheronauta'' gen. nov., a possible mandibulate from the Silurian Waukesha Lagerstätte, Wisconsin, USA |journal=Journal of Systematic Palaeontology |volume=20 |issue=1 |at=2109216 |doi=10.1080/14772019.2022.2109216 |s2cid=252839113}}</ref>{{clade|{{clade
|1=†''[[Parioscorpio|Parioscorpio venator]]''
|2={{clade
|1=†''[[Cascolus|Cascolus ravitis]]''
|2={{clade
|1=†'''''Tanazios dokeron'''''
|2={{clade
|1={{clade
|1=†''[[Captopodus|Captopodus poschmanni]]''
|2={{clade
|1=†''[[Acheronauta stimulapis]]''
|2=†[[Thylacocephala]]
}}
}}
|2={{clade
|1=†''[[Occacaris|Occacaris oviformis]]''
|2={{clade
|1={{clade
|1=[[Myriapoda]]
|2={{clade
|1=†''[[Ercaicunia|Ercaicunia multinodosa]]''
|2={{clade
|1={{clade
|1=†''[[Clypecaris|Clypecaris pteroidea]]''
|2={{clade
|1={{clade
|1={{clade
|1=†''[[Waptia|Waptia fieldensis]]''
|2=†''[[Perspicaris|Perspicaris dictynna]]'' |bar2=brown
}}
|bar2=brown
|2={{clade
|1=†''[[Canadaspis|Canadaspis perfecta]]''
|2={{clade
|1=†''[[Tokummia|Tokummia katalepsis]]''
|2=†''[[Branchiocaris|Branchiocaris pretiosa]]''
}}
}}
}}
|2={{clade
|bar1=brown
|1={{clade
|1=†''[[Nereocaris|Nereocaris exilis]]''
|2=†''[[Odaraia|Odaria alata]]''
}}
|2={{clade
|1=†[[Euthycarcinoidea]]
|label2=†[[Fuxianhuiida]]
|2={{clade
|1=†''[[Fuxianhuia]]''
|2={{clade
|1=†''[[Chengjiangocaris]]''
|2=†''[[Shankouia]]''
}}
}}
}}
}}
}}
}}
}}
}}
}}
|label2=[[Pancrustacea]]
|2={{clade
|1={{clade
|1=''[[Argulus]]''
|2=[[Ostracoda]]
}}
|2={{clade
|1={{clade
|1=†''[[Lepidocaris]]''
|2={{clade
|1=''[[Triops]]''
|2=''[[Artemia]]''
}}
}}
|2={{clade
|1={{clade
|1={{clade
|1=[[Remipedia]]
|2=[[Cephalocarida]]
}}
|2=[[Hexapoda]]
}}
|2=[[Multicrustacea]]
}}
}}
}}
}}
}}
}}
}}
}}
}}|style=width:33em;font-size:95%;line-height:70%|grouplabel1={{clade labels|label1=[[Hymenocarina]]|top1=46%}}|label1=[[Arthropoda]]}}
== References ==
{{reflist}}
{{Taxonbar|from=Q123453090}}
[[Category:Silurian arthropods of Europe]]
[[Category:Fossils of England]]
[[Category:Enigmatic arthropod taxa]]
[[Category:Homerian]]