Dolichopterus
Encyclopedia
Dolichopterus is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of the prehistoric sea scorpion
Sea Scorpion
Sea Scorpion may refer to:* Eurypterids, members of the extinct class Eurypterida* some members of the Cottidae family of fish including the Long-spined Sea Scorpion and Short-spined Sea Scorpion...

s, arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

s in the order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 Eurypterida.

Distribution

It lived in the Late Silurian (around ) in shelf or epicontinental seas of the region where Avalonia
Avalonia
Avalonia was a microcontinent in the Paleozoic era. Crustal fragments of this former microcontinent underlie south-west Great Britain, and the eastern coast of North America. It is the source of many of the older rocks of Western Europe, Atlantic Canada, and parts of the coastal United States...

, Baltica
Baltica
Baltica is a name applied by geologists to a late-Proterozoic, early-Palaeozoic continent that now includes the East European craton of northwestern Eurasia. Baltica was created as an entity not earlier than 1.8 billion years ago. Before this time, the three segments/continents that now comprise...

 and Laurentia
Laurentia
Laurentia is a large area of continental craton, which forms the ancient geological core of the North American continent...

 met during the Caledonian orogeny
Caledonian orogeny
The Caledonian orogeny is a mountain building era recorded in the northern parts of the British Isles, the Scandinavian Mountains, Svalbard, eastern Greenland and parts of north-central Europe. The Caledonian orogeny encompasses events that occurred from the Ordovician to Early Devonian, roughly...

; its fossils have been found in modern-day North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and the Baltic region
Baltic region
The terms Baltic region, Baltic Rim countries, and Baltic Rim refer to slightly different combinations of countries in the general area surrounding the Baltic Sea.- Etymology :...

. They were about 25–30 cm (9.8–11.8 ) long.

Relatives

Strobilopterus
Strobilopterus
Strobilopterus is a genus of prehistoric eurypterid of the family Dolichopteridae.-Description:Dolichopterids, which lived in the Silurian and Devonian periods, were medium-sized, and had outer surfaces that were either smooth with pustules and semilunar scales. Their compound eyes were arcuate...

probably was one of the closest relatives of Dolichopterus, but overall the phylogeny and systematics
Systematics
Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...

 of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Dolichopteridae
Dolichopteridae
Dolichopteridae are an extinct family of eurypterids that lived in the Silurian and Devonian periods.-Description:Dolichopteridae had outer surfaces that were either smooth or with pustules and semilunar scales. Their compound eyes were arcuate and located anteriorly on the prosoma . Their...

 is disputed: some place it closer to the Eurypteridae
Eurypteridae
Eurypteridae are an extinct family of eurypterids. They were members of the superfamily Eurypteroidea.-Description:Eurypteridae, which lived during the Silurian period, were characterized by small to large exoskeletons with inconspicuous semilunar scales or curved ridges. The telson, was...

, while others assign it to the second lineage of sea scorpions which contains the Stylonuridae
Stylonuridae
Stylonuridae are an extinct family of prehistoric eurypterids within the Superfamily Stylonuroidea.-Description:Stylonuridae, which lived from the Ordovician to Lower Permian periods, were small to very large forms with scales developing into tubercules and knobs. The prosoma exhibited variable...

.

Description

Dolichopteridae
Dolichopteridae
Dolichopteridae are an extinct family of eurypterids that lived in the Silurian and Devonian periods.-Description:Dolichopteridae had outer surfaces that were either smooth or with pustules and semilunar scales. Their compound eyes were arcuate and located anteriorly on the prosoma . Their...

, which lived in the Silurian and Devonian periods, had outer surfaces that were either smooth with pustules and semilunar scales. Their compound eyes were arcuate and located anteriorly on the prosoma (head). Their abdomens had epimers (lateral projections). The telson, (tail) was lanceolate. Their chelicerae were small, and the first three pairs of walking lags were stout, with powerful spines. The last pair of walking lags had supplementary lobes, while the swimming lags had the last joint enlarged, as part of the paddle. The male genital appendage was long.

Dolichopterus is distinguishable by its nearly smooth outer surface; its subquadrate prosoma (head), and the slightly serrated margins on the distal joints and lobes of the swimming legs.

Species

The following species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 have been named:
  • Dolichopterus gotlandicus Kjellesvig-Waering, 1979 – Sweden
  • Dolichopterus jewetti Caster & Kjellesvig-Waering, 1956 – USA
  • Dolichopterus macrocheirus Hall, 1859 (type species
    Type species
    In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

    ) – USA, Canada
  • Dolichopterus siluriceps Clarke & Ruedemann, 1912 – USA, Canada
  • ?Dolichopterus stoermeri Caster & Kjellesvig-Waering, 1956 – Estonia
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