Setapedites Temporal range: | |
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Fossils of Setapedites | |
Life restoration | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Family: | † Offacolidae |
Genus: | † Setapedites Lustri, Gueriau and Daley, 2024 |
Species: | †S. abundantis |
Binomial name | |
†Setapedites abundantis Lustri, Gueriau and Daley, 2024 | |
Setapedites abundantis is an Ordovician offacolid chelicerate from the Fezouata Formation of Morocco. [1]
Setapedites is roughly 6 mm long excluding the telson, with eleven body segments and a prosoma with six appendage pairs. The first appendage pairs are elongated chelicerae, with the other five being biramous appendages. The exopods of these appendages bear setae on their tips, hence the name Setapedites. The opisthosoma is divided into a pre-abdomen and an abdomen. Each pre-abdomen segment has both a pair of appendages and on the tergites, leaf-shaped tergopleurae, although somite 14 and all of the abdominal somites lack appendages. The first pre-abdominal somite has a large, flap-like exopod. The abdominal somites have fused tergites and sternites forming ring-shaped structures, alongside two pairs of spines derived from the tergopleurae. Under the 11th tergite, a small, symmetrical round structure is preserved, which may be an anal pouch. The telson as the end of the abdomen is roughly as long as the pre-abdomen, with a triangular shape. [1]
Setapedites shares similarities with Offacolus like the elongated chelicerae and limb arrangement, however the number of segments is closer to that of Dibasterium . Unusually, it also shares some features with Habelia like the anal pouch and structure of the opisthosomal tergites. [1] Phylogenic analysis shows that Setapedites is closely related to Bunaia . [2]
Setapedites translates to "foot with setae" and derives from the characteristic setae of the outer endopod segments. The specific name abundantis translates to "abundant", referring to how common the genus is within the Fezouata Formation. [1]
Marrella is an extinct genus of marrellomorph arthropod known from the Middle Cambrian of North America and Asia. It is the most common animal represented in the Burgess Shale of British Columbia, Canada, with tens of thousands of specimens collected. Much rarer remains are also known from deposits in China.
Nektaspida is an extinct order of non-mineralised artiopodan arthropods. They are known from the lower-Cambrian to the upper Silurian. Originally classified as trilobites, which they superficially resemble, they are now placed as close relatives as members of the Trilobitomorpha within Artiopoda. The order is divided into three major families; Emucarididae, Liwiidae, and Naraoiidae.
Pulmonoscorpius is an extinct genus of scorpion from the Mississippian of Scotland. It contains a single named species, Pulmonoscorpius kirktonensis. It was one of the largest scorpions to have ever lived, with the largest known individual having an estimated length exceeding 70 cm. Pulmonoscorpius retains several general arthropod features which are absent in modern scorpions, such as large lateral eyes and a lack of adaptations for a burrowing lifestyle. It was likely an active diurnal predator, and the presence of book lungs indicate that it was fully terrestrial.
Salteropterus is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Salteropterus have been discovered in deposits of Late Silurian age in Britain. Classified as part of the family Slimonidae, the genus contains one known valid species, S. abbreviatus, which is known from fossils discovered in Herefordshire, England, and a dubious species, S. longilabium, with fossils discovered in Leintwardine, also in Herefordshire. The generic name honours John William Salter, who originally described S. abbreviatus as a species of Eurypterus in 1859.
Habelia is a genus of extinct arthropod from the Middle Cambrian, thought to be one of the earliest known relatives of chelicerates. Its fossils have been found in the Burgess Shale in British Columbia, Canada. Fifty-four specimens of Habelia are known from the Greater Phyllopod bed, where they comprise 0.1% of the community.
Angustidontus is a genus of predatory pelagic crustaceans from the Late Devonian and Early Carboniferous periods, classified as part of the subclass Eumalacostraca. Fossils of the genus have been recovered in relative abundance from Canada, Germany, the Czech Republic, Poland, Belarus, Ukraine and large parts of the United States, including Oklahoma, Ohio, Indiana, Kentucky, Montana, Utah, Nevada.
Bunaia is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Bunaia was tentatively placed as part of the clade Planaterga, however a 2024 study found it to be within Offacolidae instead. The genus contains at least one species: Bunaia woodwardi from the Silurian period in Svalbard, Norway and the Bertie Group of Ontario
Weinbergina is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Fossils of the single and type species, W. opitzi, have been discovered in deposits of the Devonian period in the Hunsrück Slate, Germany.
Schinderhannes bartelsi is a species of hurdiid radiodont (anomalocaridid), known from one specimen from the Lower Devonian Hunsrück Slates. Its discovery was astonishing because the latest definitive radiodonts were known only from the Early Ordovician, at least 66 million years earlier than this taxon.
Haikoucaris is a genus of megacheiran arthropod that contains the single species Haikoucaris ercaiensis. It was discovered in the Cambrian Chengjiang biota of China.
The Fezouata Formation or Fezouata Shale is a geological formation in Morocco which dates to the Early Ordovician. It was deposited in a marine environment, and is known for its exceptionally preserved fossils, filling an important preservational window beyond the earlier and more common Cambrian Burgess shale-type deposits. The fauna of this geological unit is often described as the Fezouata biota, and the particular strata within the formation which exhibit exceptional preservation are generally termed the Fezouata Lagerstätte.
Tariccoia is a genus of nektaspid arthropods belonging to the family Liwiidae, known from fossils found in Ordovician strata in Sardinia and Morocco. It is between 2.5 centimetres (0.98 in) and 6 centimetres (2.4 in) long. It has a headshield wider than the tailshield (pygidium), and in between them three thoracic body segments (somites).
Periclimenes pholeter, is a species of shrimp belonging to the family Palaemonidae. The species is closest to Periclimenes indicus, P. obscurus and P. toloensis, resembling these species in the presence of an epigastric tooth on the carapace, the shape of the abdomen, the spinulation of the carapace, and the unarmed fingers of the first chelipeds. P. pholeter most resembles P. indicus by the elongatecarpus and long fingers of the second pereiopods, differing in these features from P. toloensis, which has the fingers slightly less than half as long as the palm. In P. obscurus the fingers are shorter than the palm, but the carpus is about as long as the palm. From P. indicus, this species differs: by the greater size; by the much higher rostrum and the greater number of ventral rostral teeth; by the shorter eye; by the less slender antennular peduncle; by the more deeply cleft upper antennular flagellum; by the more robust scaphocerite; by the fingers of the first pereiopods ; by the more slender pereiopods, especially the fifth, which is much longer than the ischium.
Aegirocassis is an extinct genus of giant radiodont arthropod belonging to the family Hurdiidae that lived 480 million years ago during the early Ordovician in the Fezouata Formation of Morocco. It is known by a single species, Aegirocassis benmoulai. Van Roy initiated scientific study of the fossil, the earliest known of a "giant" filter-feeder discovered to date. Aegirocassis is considered to have evolved from early predatory radiodonts. This animal is characterized by its long, forward facing head sclerite, and the endites on its frontal appendages that bore copious amounts of baleen-like auxiliary spines. This animal evolving filter-feeding traits was most likely a result of the Great Ordovician Biodiversification Event, when environmental changes caused a diversification of plankton, which in turn allowed for the evolution of new suspension feeding lifeforms. Alongside the closely related Pseudoangustidontus, an unnamed hurdiid from Wales, the middle Ordovician dinocaridid Mieridduryn, and the Devonian hurdiid Schinderhannes this radiodont is one of the few dinocaridids known from post-Cambrian rocks.
Alpheus tricolor is a crustacean belonging to the family of snapping shrimp. It was first isolated in Indonesia and Sri Lanka. It counts with a setose carapace, an acute rostrum, shallow adrostral furrows and a basicerite with a strong ventrolateral tooth. The lamella of its scaphocerite is not reduced, with an anterior margin that is concave. Its third maxilliped counts with an epipodial plate bearing thick setae, while its first chelipeds are found with their merus bearing a strong disto-mesial tooth; its third pereiopod has an armed ischium, with a simple and conical dactylus. Its telson is broad, distally tapering, with 2 pairs of dorsal spines. The species is named after its characteristic colour pattern, including white, red and orange.
Offacolidae is a family of basal euchelicerate arthropods from the Ordovician and Silurian of Europe, Morocco and North America. The family is united by several features, including paddle-like sixth post-cheliceral appendages, elongated chelicerae, and reduced first tergites. They share with most other euchelicerates a wide carapace, which has led to them being placed in the paraphyletic “Synziphosurina” for a long time, however more detailed studies have led to them being separated.
Camanchia is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Camanchia was regarded as part of the clade Prosomapoda. Fossils of the single and type species, C. grovensis, have been discovered in deposits of the Silurian period in Iowa, in the United States. Alongside Venustulus, Camanchia is one of the only Silurian synziphosurine with fossil showing evidence of appendages.
Palaeoisopus is a monotypic genus of fossil pycnogonid, known only by one species, Palaeoisopus problematicus, discovered from the Lower Devonian Hunsrück Slate of Germany. It have several characters unusual for a pycnogonid, such as swimming legs with alternating size, medially-arranged eyes, and most significantly, a long, segmented abdomen, which were highly reduced in modern counterparts.
Pseudoangustidontus is a genus of hurdiid (peytoiid) radiodont from the Lower Ordovician of Morocco. This genus is known from two described species, P. duplospineus and P. izidigua, with some specimens that are hard to determine which species to belong to. This animal is only known from the Fezouata Formation, a fossil site in Morocco that is of Lagerstätte status, meaning that the fossils from this site are exceptionally preserved. Because of its partial remains, its classification was debated, but with more complete fossils it is identified as radiodont frontal appendage.
Apankura machu is a Cambrian euthycarcinoid from the Santa Rosita Formation of Argentina. It was at one point the only Cambrian euthycarcinoid. However, Mosineia and Mictomerus are likely older.