Kodymirus

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Kodymirus
Temporal range: Cambrian Series 2 521–509  Ma
Kodymirus Reconstruction.jpg
Artist's restoration
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
(unranked): Artiopoda
(unranked): Vicissicaudata
Genus: Kodymirus
Chlupáč & Havlíček, 1965
Species:
K. vagans
Binomial name
Kodymirus vagans
Chlupáč & Havlíček, 1965

Kodymirus is a genus of Early Cambrian arthropod, known from the Czech Republic, which bears some resemblance to eurypterids and aglaspidids. Although it possessed great appendage-like raptorial arms, it was not homologous with those of megacheirans, and was instead a member of Vicissicaudata, closely related to aglaspidids. It is part of a small and low-diversity Paseky Shale fauna group, which dwelt in brackish waters. [1]

Contents

Description

Kodymirus was a small predator at 80 mm (3.1 in) long. Its distinctive feature is pair of large, serrated raptorial appendages. These appendages appear convergent to those of megacheirans and radiodonts, but are not homologous as they postantennular, suggesting raptorial arms evolved multiple times in Cambrian arthropods. [2]

Kodymirus is an enigmatic arthropod, and its precise taxonomic affinity remains uncertain. It was initially believed to be an early eurypterid and later a megacheiran, but today it is best considered to be a stem-group or ally of the aglaspidids. [2] [1] Its basipods closely resembles those of Emeraldella , [2] and is suggested to be related to Beckwithia due to the presence of axial spines. [3]

Paleoecology

Restoration of Kodymirus vagans hunting prey in brackish waters Kodymirus vagans.jpg
Restoration of Kodymirus vagans hunting prey in brackish waters

Kodymirus inhabited the Paseky Shale, within the modern day Czech Republic, which may be a shallow marine environment or brackish estuary. [2] [4] Trace fossils from the Shale have been interpreted as Kodymirus raking its claws along the sediment while swimming, disturbing benthic prey buried beneath the muck. This would make Kodymirus the earliest known arthropod predator in the intertidal zone. [2]

Related Research Articles

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Eurypterids, often informally called sea scorpions, are a group of extinct arthropods that form the order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period 467.3 million years ago. The group is likely to have appeared first either during the Early Ordovician or Late Cambrian period. With approximately 250 species, the Eurypterida is the most diverse Paleozoic chelicerate order. Following their appearance during the Ordovician, eurypterids became major components of marine faunas during the Silurian, from which the majority of eurypterid species have been described. The Silurian genus Eurypterus accounts for more than 90% of all known eurypterid specimens. Though the group continued to diversify during the subsequent Devonian period, the eurypterids were heavily affected by the Late Devonian extinction event. They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event 251.9 million years ago.

<i>Yohoia</i> Extinct genus of arthropods

Yohoia is an extinct genus of megacheiran arthropod from the Cambrian period that has been found as fossils in the Burgess Shale formation of British Columbia, Canada. The type species, Yohoia tenuis, was described in 1912 by Walcott, who considered it an anostracan crustacean. 711 specimens of Yohoia are known from the Greater Phyllopod bed, where they comprise 1.35% of the community. In 2015, Conway Morris et al. reported another species, Y. utahana, from the Marjum Formation, Utah.

<span class="mw-page-title-main">Dinocaridida</span> Extinct class of basal arthropods

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<i>Anomalocaris</i> Extinct genus of cambrian radiodont

Anomalocaris is an extinct genus of radiodont, an order of early-diverging stem-group arthropods.

<span class="mw-page-title-main">Cheloniellida</span> Order of arthropods (fossil)

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<i>Pambdelurion</i> Extinct genus of Arthropod

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<i>Parapeytoia</i> Extinct genus of arthropods

Parapeytoia is a genus of Cambrian arthropod. The type and only described species is Parapeytoia yunnanensis, lived over 518 million years ago in the Maotianshan shales of Yunnan, China. Unidentified fossils from the same genus also had been discovered from the nearby Wulongqing Formation.

<i>Hughmilleria</i> Genus of extinct arthropods

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<span class="mw-page-title-main">Megacheira</span> Extinct class of arthropods

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<i>Haikoucaris</i> Extinct genus of arthropods

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<i>Occacaris</i> Extinct genus of arthropods

Occacaris oviformis is an extinct nektonic predatory arthropod from the Lower Cambrian Maotianshan shale Lagerstätte. It bears a superficial resemblance to the Cambrian arthropod, Canadaspis, though, was much smaller, and had a pair of "great appendages", with which it may have grasped prey. It was originally considered to belong to Megacheira, however it is questioned in later study.

<span class="mw-page-title-main">Radiodonta</span> Extinct order of basal arthropods

Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and used for a variety of functions. Radiodonts are among the earliest large predators, but they also included sediment sifters and filter feeders. Some of the most famous species of radiodonts are the Cambrian taxa Anomalocaris canadensis, Hurdia victoria, Peytoia nathorsti, Titanokorys gainesi, Cambroraster falcatus and Amplectobelua symbrachiata. The later surviving members include the subfamily Aegirocassisinae from the Early Ordovician of Morocco and the Early Devonian member Schinderhannes bartelsi from Germany.

Kockurus is a problematic genus of Cambrian arthropod, known from the Czech Republic, which bears some resemblance to the eurypterids, aglaspidids and chelicerates. It is diagnostic of a small and low-diversity fauna endemic to the area, which dwelt in brackish waters.

<i>Cucumericrus</i> Extinct genus of arthropod

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<i>Worthenella</i> Extinct genus of arthropods

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<span class="mw-page-title-main">Hughmilleriidae</span> Extinct family of eurypterids

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<span class="mw-page-title-main">Artiopoda</span> Extinct group of arthropods

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<i>Strabops</i> Extinct genus of arthropods

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<i>Cheloniellon</i> Extinct genus of arthropods

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<i>Kylinxia</i> Genus of fossil arthropod

Kylinxia is a genus of extinct arthropod described in 2020. It was described from six specimens discovered in Yu'anshan Formation in southern China. The specimens are assigned to one species Kylinxia zhangi. Dated to 518 million years, the fossils falls under the Cambrian period. Announcing the discovery on 4 November 2020 at a press conference, Zeng Han of the Nanjing Institute of Geology and Paleontology, said that the animal "bridges the evolutionary gap from Anomalocaris to true arthropods and forms a key ‘missing link’ in the origin of arthropods," which was "predicted by Darwin’s evolutionary theory." The same day the formal description was published in Nature.

References

  1. 1 2 Chlupáč, I. "Lower Cambrian arthropods from the Paseky Shale (Barrandian area, Czech Republic)". Journal of the Czech Geological Society . 40 (4): 9–36. Retrieved 2009-06-06.
  2. 1 2 3 4 5 Lamsdell, James C.; Stein, Martin; Selden, Paul A. (2013-09-01). "Kodymirus and the case for convergence of raptorial appendages in Cambrian arthropods". Naturwissenschaften. 100 (9): 811–825. doi:10.1007/s00114-013-1081-y. ISSN   1432-1904.
  3. Ortega-Hernández, O; Legg, A; Braddy, J (2014). "The phylogeny of aglaspidid arthropods and the internal relationships within Artiopoda (project)". MorphoBank datasets. Retrieved 2022-09-28.
  4. "Ichnotaxonomy of the Cambrian Spence Shale Member of the Langston formation, Wellsville Mountains, Northern Utah, USA". Paleontological Contributions. 2018. doi: 10.17161/1808.26428 . hdl: 1808/26428 . ISSN   1946-0279.