''Cyamocephalus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

synziphosurine Synziphosurina is a paraphyletic group of chelicerate arthropods previously thought to be basal horseshoe crabs (Xiphosura). It was later identified as a grade composed of various basal euchelicerates, eventually excluded form the monophyletic Xi ...

, a

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

group of fossil

chelicerate The subphylum Chelicerata (from New Latin, , ) constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, horseshoe crabs, and arachnids (including harvestmen, scorpions, spiders, solifuges, ticks, ...

arthropods Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chitin, oft ...

. ''Cyamocephalus'' was regarded as part of the clade

Planaterga Planaterga is a clade of prosomapod euchelicerates including several synziphosurid genera (mainly bunodids and pseudoniscids) and the group Dekatriata (which in turn includes arachnids, chasmataspidids and eurypterid Eurypterids, often ...

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 preserved ...

s of the single and

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

, ''C. loganensis'', have been discovered in

deposits A deposit account is a bank account maintained by a financial institution in which a customer can deposit and withdraw money. Deposit accounts can be savings accounts, current accounts or any of several other types of accounts explained below. ...

of the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 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 shortest period of the Paleozoi ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

Lesmahagow Lesmahagow ( ; sco, Lismahagie or ''Lesmahagae'', gd, Lios MoChuda) is a small town in the historic county of Lanarkshire on the edge of moorland, near Lanark in the central belt of Scotland. Lesmahagow was also a civil parish. It lies west o ...

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to th ...

(in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

). ''Cyamocephalus'' is one of the two members of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Pseudoniscidae Pseudoniscidae is an extinct family of synziphosurine chelicerates that lived in the Silurian. Pseudoniscidae is classified inside the clade Planaterga, alongside Bunodidae and Dekatriata ( chasmataspidids, eurypterids and arachnids). Pseudonisci ...

, the other being ''

Pseudoniscus ''Pseudoniscus'' is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. ''Pseudoniscus'' was regarded as part of the clade Planaterga. Fossils of the genus have been discovered in deposits of the Silurian period i ...

''. ''Cyamocephalus'' differ from ''Pseudoniscus'' by the fused tergites of 6th and 7th opisthosomal segments.

References

Synziphosurina Planaterga Silurian first appearances Silurian arthropods Fossils of Scotland Fossil taxa described in 1927 {{Chelicerata-stub