Drepanopterus
Encyclopedia
Drepanopterus is an extinct genus of eurypterid
. There are currently two species assigned to the genus. The genus has in the past been assigned its own family, with nine species associated with the genus Drepanopterus, however five of these have since been proven to be synonyms of pre-existing species, assigned to their own genera, or found to be based on insubstantial fossil data (the holotype of one proved to be a lithic clast).
Drepanopterus pentlandicus was first described from the Silurian
strata of the Pentland Hills
in Scotland
. The only other fully described valid species is Drepanopterus abonensis, from the Upper Devonian
of Portishead, Somerset
. The exact relationship of Drepanopterus to other Eurypterid
s has long been unclear, however it is now apparent that it is a primitive hibbertopteroid, and an early relative of the Carboniferous
Hibbertopterus
.
ranges from styliform to clavate. Drepanopterus date from the Silurian to the Upper Devonian periods.
Eurypterid
Eurypterids are an extinct group of arthropods related to arachnids which include the largest known arthropods that ever lived. They are members of the extinct order Eurypterida ; which is the most diverse Paleozoic chelicerate order in terms of species...
. There are currently two species assigned to the genus. The genus has in the past been assigned its own family, with nine species associated with the genus Drepanopterus, however five of these have since been proven to be synonyms of pre-existing species, assigned to their own genera, or found to be based on insubstantial fossil data (the holotype of one proved to be a lithic clast).
Drepanopterus pentlandicus was first described from the Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
strata of the Pentland Hills
Pentland Hills
The Pentland Hills are a range of hills to the south-west of Edinburgh, Scotland. The range is around 20 miles in length, and runs south west from Edinburgh towards Biggar and the upper Clydesdale.Some of the peaks include:* Scald Law...
in Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
. The only other fully described valid species is Drepanopterus abonensis, from the Upper Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
of Portishead, Somerset
Portishead, Somerset
Portishead is a coastal town on the Severn Estuary within the unitary authority of North Somerset, which falls within the ceremonial county of Somerset England. It has a population of 22,000, an increase of over 3,000 since the 2001 census, with a growth rate of 40 per cent, considerably in excess...
. The exact relationship of Drepanopterus to other Eurypterid
Eurypterid
Eurypterids are an extinct group of arthropods related to arachnids which include the largest known arthropods that ever lived. They are members of the extinct order Eurypterida ; which is the most diverse Paleozoic chelicerate order in terms of species...
s has long been unclear, however it is now apparent that it is a primitive hibbertopteroid, and an early relative of the Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
Hibbertopterus
Hibbertopterus
Hibbertopterus is a genus of giant sea scorpion that inhabited the swamps of Scotland during the Carboniferous.Hibbertopterus is a member of the family Hibbertopteridae, large bizarre Eurypterids found from the Upper Devonian to the end of the Permian period...
.
Description
Drepanopterus is distinguished by its "fairly large" size, compound eyes with parallel axes on a subrectangular to subovate prosoma (head). All of its legs are walking legs; the first three pairs are short and powerful, with spines; the last two pairs are moderately long, ending in strongly curved terminal claw. The last leg reaches as far as the penultimate abdominal segment. The telsonTelson
The telson is the last division of the body of a crustacean. It is not considered a true segment because it does not arise in the embryo from teloblast areas as do real segments. It never carries any appendages, but a forked "tail" called the caudal furca is often present. Together with the...
ranges from styliform to clavate. Drepanopterus date from the Silurian to the Upper Devonian periods.
Species
- Drepanopterus Laurie, 1892
- Drepanopterus abonensis Simpson, 1951 — Devonian, England
- Drepanopterus pentlandicus Laurie, 1892 — Silurian, Scotland