Cowiedesmus Temporal range: | |
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Scientific classification | |
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Order: | †Cowiedesmida |
Family: | †Cowiedesmidae |
Genus: | †Cowiedesmus Wilson & Anderson, 2004 |
Type species | |
Cowiedesmus eroticopodus |
Cowiedesmus is an extinct millipede genus described from Scotland, [1] and is considered as earliest known land animals alongside Pneumodesmus from same formation. [2] It is originally considered that it is from the middle Silurian, a 2017 study suggested that the geological formation it contains actually appears to be from the Early Devonian (Lochkovian) instead. [3] Although a 2023 study confirmed the age identification of the 2004 study through palynological, palaeobotanical and ziron analyses incorporating newly discovered additional data, [4] this is based on adjacent structurally separated block with different stratigraphy and sedimentology to the block with fossil site it was discovered, and it is confirmed as unsustainable. [5] Cowiedesmus was about 4 cm (1.6 in) long and characterized by a greatly enlarged pair of legs on the 8th segment which may have been used in clasping females or functioned as gonopods (modified legs used to insert sperm during mating). Coweiedesmus is distinct enough from other living and fossil millipedes to be placed in its own order, Cowiedesmida. The only known species, C. eroticopodus, was described in 2004. [1]
The name Cowiedesmus references the Cowie Formation, a geological formation at Cowie Harbor, near the village of Stonehaven, Scotland, where the fossil was found and desmus, a common root word in millipede nomenclature meaning "bond" or "bridge". The specific epithet eroticopodus means "erotic foot". [1]
The Devonian is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at 419.2 million years ago (Ma), to the beginning of the succeeding Carboniferous period at 358.9 Ma. It is named after Devon, South West England, where rocks from this period were first studied.
The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago (Mya), to the beginning of the Devonian Period, 419.2 Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out.
Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derived from this feature. Each double-legged segment is a result of two single segments fused together. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a tight ball. Although the name "millipede" derives from Latin for "thousand feet", no species was known to have 1,000 or more until the discovery in 2020 of Eumillipes persephone, which can have over 1,300 legs. There are approximately 12,000 named species classified into 16 orders and around 140 families, making Diplopoda the largest class of myriapods, an arthropod group which also includes centipedes and other multi-legged creatures.
Stonehaven is a town in Scotland. It lies on Scotland's northeast coast and had a population of 11,602 at the 2011 Census. After the demise of the town of Kincardine, which was gradually abandoned after the destruction of its royal castle in the Wars of Independence, the Scottish Parliament made Stonehaven the successor county town of Kincardineshire. It is currently administered as part of the Aberdeenshire Council Area. Stonehaven had grown around an Iron Age fishing village, now the "Auld Toon", and expanded inland from the seaside. As late as the 16th century, old maps indicate the town was called Stonehyve, Stonehive, Timothy Pont also adding the alternative Duniness. It is known informally to locals as Stoney.
Old Red Sandstone, abbreviated ORS, is an assemblage of rocks in the North Atlantic region largely of Devonian age. It extends in the east across Great Britain, Ireland and Norway, and in the west along the eastern seaboard of North America. It also extends northwards into Greenland and Svalbard. These areas were a part of the paleocontinent of Euramerica (Laurussia). In Britain it is a lithostratigraphic unit to which stratigraphers accord supergroup status and which is of considerable importance to early paleontology. The presence of Old in the name is to distinguish the sequence from the younger New Red Sandstone which also occurs widely throughout Britain.
Myriapods are the members of subphylum Myriapoda, containing arthropods such as millipedes and centipedes. The group contains about 13,000 species, all of them terrestrial.
Eurypterus is an extinct genus of eurypterid, a group of organisms commonly called "sea scorpions". The genus lived during the Silurian period, from around 432 to 418 million years ago. Eurypterus is by far the most well-studied and well-known eurypterid. Eurypterus fossil specimens probably represent more than 95% of all known eurypterid specimens.
Arthropleuridea is an extinct subclass of myriapod arthropods that flourished during the Carboniferous period, having first arisen during the Silurian, and perishing in the Early Permian. Members are characterized by possessing diplosegement paranotal tergal lobes separated from the body axis by a suture, and by sclerotized plates buttressing the leg insertions. Despite their unique features, recent phylogenetic research suggests Arthropleuridea be included among millipedes in the class Diplopoda. The subclass contains three recognized orders, each with a single genus.
Anaspida is an extinct group of jawless fish that existed from the early Silurian period to the late Devonian period. They were classically regarded as the ancestors of lampreys, but it is denied in recent phylogenetic analysis, although some analysis show these group would be at least related. Anaspids were small marine fish that lacked a heavy bony shield and paired fins, but were distinctively hypocercal.
Hylonomus is an extinct genus of reptile that lived 318 million years ago during the Bashkirian stage of the Late Carboniferous. It is the earliest known crown group amniote and the oldest known unquestionable reptile, with the only known species being Hylonomus lyelli. Despite being amongst the oldest known reptiles, it is not the most primitive member of the group, being a eureptile more derived than either parareptiles or captorhinids.
Pneumodesmus newmani is a species of myriapod. It is originally considered that it lived during the late Wenlock epoch of the Silurian period around 428 million years ago. However, a 2017 study dates its occurrence based on zircon data analysis as the Early Devonian (Lochkovian). Although the 2023 study confirmed the age identification of the 2004 study through palynological, palaeobotanical and zircon analyses incorporating newly discovered additional data, this is based on adjacent structurally separated block with different stratigraphy and sedimentology to the block with fossil site it was discovered, and it is confirmed as unsustainable. It is one of the first myriapods, and among the oldest creatures to have lived on land. It was discovered in 2004, and is known from a single specimen from Stonehaven, Aberdeenshire, Scotland.
Cowie is an historic fishing village in Kincardineshire, Scotland. This village has existed since the Middle Ages, but in current times it is effectively subsumed into the town of Stonehaven. It had an estimated population of 2,720 in 2020.
The Carboniferous rainforest collapse (CRC) was a minor extinction event that occurred around 305 million years ago in the Carboniferous period. The event occurred at the end of the Moscovian and continued into the early Kasimovian stages of the Pennsylvanian.
Archipolypoda is an extinct group of millipedes known from fossils in Europe and North America and containing the earliest known land animals. The Archipolypoda was erected by Scudder (1882) but redefined in 2005 with the description of several new species from Scotland. Distinguishing characteristics include relatively large eyes with densely packed ocelli, and modified leg pairs on the 8th body ring. Some species had prominent spines while others had a flattened appearance.
The Cowie Formation is geological formation located on the Highland Boundary Fault between the fishing village of Cowie and Ruthery Head, in Aberdeenshire, Scotland. Age of this formation is controversial, that was originally estimated at the Middle Silurian, Wenlock to Ludlow, but zircon geochronology shows the Early Devonian, Lochkovian instead. In study published in 2023, according to spore microfossils and additional zircon data, the Middle Silurian, late Wenlock age is suggested again. However, in 2024 it is considered as unsustainable because this conclusion is based on adjacent structurally separated block with different stratigraphy and sedimentology to the block with fossil productive Fish Bed. This formation preserves fossils, including a millipedes such as Pneumodesmus and Cowiedesmus that were discovered by Mike Newman in 2001, and some agnathan like Cowielepis.
The Stonehaven Group is a geologic group in Scotland. It preserves fossils dating back to the Silurian period. Fossils of cryptospores, such as the hilate cryptospore Hispanaediscus lamontii, have been found in this geologic group, along with miospores and other plant fragments.
Cowielepis is an extinct genus of jawless fish in the class Anaspida. It is from the Cowie Harbour fish bed of Stonehaven, Scotland, which age is considered as the Silurian, or Early Devonian (Lochkovian).
Parioscorpio is an extinct genus of arthropod containing the species P. venator known from the Silurian-aged Waukesha Biota of the Brandon Bridge Formation near Waukesha, Wisconsin. This animal has gone through a confusing taxonomic history, being called an arachnid, crustacean, and an artiopodan arthropod at various points. This animal is one of the more famous fossil finds from Wisconsin, due to the media coverage it received based on its original description in 2020 as a basal scorpion.
Kampecaris is an extinct genus comprising the Kampecarida, an enigmatic group of millipede-like arthropods, from the Silurian and early Devonian periods of Scotland and England. They are among the oldest known land-dwelling animals. They were small, short-bodied animals with three recognizable sections: an oval head divided along the midline, ten limb-bearing segments forming a cylindrical trunk that tapered slightly towards the front, and a characteristic swollen tail formed by a modified segment that tapers at its rear into an "anal segment". The cuticle forming their exoskeletons was thick, heavily calcified, and composed of two layers.
Coalbrookdale Formation, earlier known as Wenlock Shale or Wenlock Shale Formation and also referred to as Herefordshire Lagerstätte in palaeontology, is a fossil-rich deposit (Konservat-Lagerstätte) in Powys and Herefordshire at the England–Wales border in UK. It belongs to the Wenlock Series of the Silurian Period within the Homerian Age. It is known for its well-preserved fossils of various invertebrate animals many of which are in their three-dimensional structures. Some of the fossils are regarded as earliest evidences and evolutionary origin of some of the major groups of modern animals.