Maldybulakia

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Maldybulakia
Temporal range: Pridoli–Frasnian
Maldybulakia.png
Multiple species of Maldybulakia, M. malcomi (B), M. angusi (C), M. mirabilis (D).
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: incertae sedis
Genus:† Maldybulakia
Tesakov & Alekseev, 1998
Species

M. mirabilisTesakov & Alekseev, 1992 (type)
M. angusiEdgecombe, 1998
M. malcomiEdgecombe, 1998
M. saierensisZong et al., 2023

Contents

Synonyms

LophodesmusTesakov & Alekseev, 1992

Maldybulakia is a genus of freshwater arthropod which lived during Late Silurian to Late Devonian. [1] [2] [3] Maldybulakia is known from three species, M. angusi and M. malcolmi from Australia, M. mirabilis from Kazakhstan, and M. saierensis from China. Its classification is uncertain, it was originally described as a myriapod-like animal, and later considered related to the xiphosurans, or an artiopod. [4] [3] [5]

Discovery and etymology

In 1992, the type species of Maldybulakia is described from the Pragian to Emsian-aged Sheshen'karinskaya Formation (also known as the Sheshenkarinskoy Suite [6] ) in central Kazakhstan, with scientific name Lophodesmus mirabilis. [1] [2] The genus name Lophodesmus came from the Greek lophos ("tubercle") and desmos ("bond"), and the species name mirabilis means "wonderful" in Latin. However, this genus name is already used for an extant genus of myriapod, and in 1998, the new genus name Maldybulakia, named after Maldybulak Farm in the Bayanaul District, Pavlodar Region in Kazakhstan, was given to the animal. [7] In addition, in 1998, two new species of Maldybulakia were described from two localities in the Devonian of New South Wales. M. angusi is described from the Lochkovian to earliest Pragian-aged Sugarloaf Creek Formation, M. malcomi is from Saltwater Creek Forest Road, usually regarded as Middle Devonian in age though some fossil contents give estimation between the Givetian to the Frasnian. [1] The two species were named after Australian musicians Malcolm and Angus Young. [1] In 2023, new species M. saierensis is described from Pridoli-aged ‘Xiemisitai’ Formation in Saier Mountains, Hoboksar, western Junggar, Xinjiang, northwest China, and it is the earliest record of the genus. [3]

Morphology

Maldybulakia is a large-sized arthropod around 10 cm (3.9 in), characterized with flat diplosegments like myriapods. [2] M. malcomi had trunks up to 11.5 cm (4.5 in), and had relatively minor serial variation on the pleurotergites. M. malcomi lacked long paratergal spines, posteromedian spines, and tuberculation. M. angusi had considerable serial variation on the pleurotergites. M. angusi is characterized with very long paratergal spines on the most bilobate trunk pleurotergites. Inferred width across spines up to approximately 11.5 cm (4.5 in). [1] M. saierensis is characterized by having long paratergal spines on pleurotergites. Width of paratergal spines measures up to over 31.67 mm (1.247 in). [3]

Paleoecology

All species of Maldybulakia are known from freshwater sediments. [1] [6] [3] According to the only associated fossils, the abundant lycopod flora with M. malcolmi and the presence of spiracles suggests terrestrial habits for Maldybulakia. [1] M. saierensis from late Silurian is the oldest body fossil of a putative freshwater arthropod other than from Laurussia. [3]

Classification

Reconstruction of Willwerathia, xiphosuran possibly related to Maldybulakia. 20200928 Willwerathia laticeps.png
Reconstruction of Willwerathia , xiphosuran possibly related to Maldybulakia.

Due to lack of information on the cephalic structure, appendages, position of the gonopore and genital morphology, it is controversial where to place Maldybulakia within Arthropoda. In 1992, it was classified as Arthropoda incertae sedis , as its characteristics did not permit its identification as a members of Kampecarida, Euthycarcinoidea and Arthropleurida. [2] In 1998, it was classified as a possible Dignatha in Myriapoda, rather than the alternatively proposed Crustacea. [1] After 2010s, Maldybulakia is commonly treated as a xiphosuran, a group including modern horseshoe crabs, due to morphological similarity with the synziphosurine Willwerathia . [4] [6] [8] In 2020, morphology of Willwerathia is compared to Cambrian artiopod Falcatamacaris . [5] Since known fossils are incomplete, taxonomic positions is not discussed at description of M. saierensis. [3]

Related Research Articles

<span class="mw-page-title-main">Chelicerata</span> Subphylum of arthropods

The subphylum Chelicerata constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, horseshoe crabs, and arachnids, as well as a number of extinct lineages, such as the eurypterids and chasmataspidids.

<span class="mw-page-title-main">Xiphosura</span> Order of marine chelicerates

Xiphosura is an order of arthropods related to arachnids. They are more commonly known as horseshoe crabs. They first appeared in the Hirnantian. Currently, there are only four living species. Xiphosura contains one suborder, Xiphosurida, and several stem-genera.

<span class="mw-page-title-main">Arachnomorpha</span> Clade of arthropods

Arachnomorpha is a proposed subdivision or clade of Arthropoda, comprising the group formed by the trilobites and their close relatives (Artiopoda), Megacheira and chelicerates. Under this proposed classification scheme, Arachnomorpha is considered the sister group to Mandibulata.

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

Cheloniellida is a taxon of extinct Paleozoic arthropods. As of 2018, 7 monotypic genera of cheloniellids had been formally described, whose fossils are found in marine strata ranging from Ordovician to Devonian in age. Cheloniellida has a controversial phylogenetic position, with previous studies associated it as either a member or relative of various fossil and extant arthropod taxa. It was later accepted as a member of Vicissicaudata within Artiopoda.

<span class="mw-page-title-main">Chasmataspidida</span> Order of arthropods

Chasmataspidids, sometime referred to as chasmataspids, are a group of extinct chelicerate arthropods that form the order Chasmataspidida. Chasmataspidids are probably related to horseshoe crabs (Xiphosura) and/or sea scorpions (Eurypterida), with more recent studies suggest that they form a clade (Dekatriata) with Eurypterida and Arachnida. Chasmataspidids are known sporadically in the fossil record through to the mid-Devonian, with possible evidence suggesting that they were also present during the late Cambrian. Chasmataspidids are most easily recognised by having an opisthosoma divided into a wide forepart (preabdomen) and a narrow hindpart (postabdomen) each comprising 4 and 9 segments respectively. There is some debate about whether they form a natural group.

<i>Jaekelopterus</i> Extinct Devonian species of the Eurypterida (sea scorpions)

Jaekelopterus is a genus of predatory eurypterid, a group of extinct aquatic arthropods. Fossils of Jaekelopterus have been discovered in deposits of Early Devonian age, from the Pragian and Emsian stages. There are two known species: the type species J. rhenaniae from brackish to fresh water strata in the Rhineland, and J. howelli from estuarine strata in Wyoming. The generic name combines the name of German paleontologist Otto Jaekel, who described the type species, and the Greek word πτερόν (pteron) meaning "wing".

<i>Willwerathia</i> Genus of horseshoe crab relatives

Willwerathia is a genus of Devonian arthropod. It is sometimes classified as synziphosurine, a paraphyletic group of horseshoe crab-like fossil chelicerate arthropods, while some studies compare its morphology to an artiopod. Willwerathia known only by one species, Willwerathia laticeps, discovered in deposits of the Devonian period from the Klerf Formation, in the Rhenish Slate Mountains of Germany.

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

Euthycarcinoidea are an enigmatic group of extinct possibly amphibious arthropods that ranged from Cambrian to Triassic times. Fossils are known from Europe, North America, Argentina, Australia and Antarctica.

<i>Bembicosoma</i> Extinct genus of chelicerate

Bembicosoma is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Bembicosoma was regarded as part of the clade Planaterga. Fossils of the single and type species, B. pomphicus, have been discovered in deposits of the Silurian period in the Pentland Hills, Scotland. Bembicosoma had been tentatively assigned as an eurypterid before its synziphosurine affinities revealed.

<i>Cyamocephalus</i> Extinct genus of chelicerate

Cyamocephalus is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Cyamocephalus was regarded as part of the clade Planaterga. Fossils of the single and type species, C. loganensis, have been discovered in deposits of the Silurian period in Lesmahagow, Scotland. Cyamocephalus is one of the two members of the family Pseudoniscidae, the other being Pseudoniscus. Cyamocephalus differ from Pseudoniscus by the fused tergites of 6th and 7th opisthosomal segments.

<i>Pasternakevia</i> Extinct genus of chelicerate

Pasternakevia is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Pasternakevia was regarded as part of the clade Planaterga. Fossils of the single and type species, P. podolica, have been discovered in deposits of the Silurian period in Podolia, Ukraine.

<i>Pseudoniscus</i> Extinct genus of chelicerate

Pseudoniscus is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Pseudoniscus was regarded as part of the clade Planaterga. Fossils of the genus have been discovered in deposits of the Silurian period in the United Kingdom, the United States and Estonia. Pseudoniscus is one of the two members of the family Pseudoniscidae, the other being Cyamocephalus.

<i>Weinbergina</i> Extinct genus of chelicerate

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.

<span class="mw-page-title-main">Synziphosurina</span> Group of arthropods

Synziphosurina is a paraphyletic group of chelicerate arthropods previously thought to be basal horseshoe crabs (Xiphosura). It was later identified as a grade composed of various basal euchelicerates, eventually excluded form the monophyletic Xiphosura sensu stricto and only regarded as horseshoe crabs under a broader sense. Synziphosurines survived at least since early Ordovician to early Carboniferous in ages, with most species are known from the in-between Silurian strata.

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

Borchgrevinkium is an extinct genus of chelicerate arthropod. A fossil of the single and type species, B. taimyrensis, has been discovered in deposits of the Early Devonian period in the Krasnoyarsk Krai, Siberia, Russia. The name of the genus honors Carsten Borchgrevink, an Anglo-Norwegian explorer who participated in many expeditions to Antarctica. Borchgrevinkium represents a poorly known genus whose affinities are uncertain.

<span class="mw-page-title-main">Timeline of eurypterid research</span>

This timeline of eurypterid research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of eurypterids, a group of extinct aquatic arthropods closely related to modern arachnids and horseshoe crabs that lived during the Paleozoic Era.

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

Houia is an extinct genus of dekatriatan, a clade of chelicerate arthropods. Fossils of Houia have been discovered in deposits of the Early Devonian period in Guangxi and Yunnan, both in China. The genus contains two species: H. guangxiensis, from the Pragian to Emsian epoch of Guangxi; and H. yueya, the type species, from the Lochkovian epoch of Yunnan. The name of the genus is derived from the Chinese character 鲎 (hòu), meaning "horseshoe crab".

<i>Venustulus</i> Extinct genus of chelicerate from Wisconsin

Venustulus is a genus of synziphosurine, a paraphyletic group of fossil chelicerate arthropods. Venustulus was regarded as part of the clade Prosomapoda. Fossils of the single and type species, V. waukeshaensis, have been discovered in deposits of the Silurian period in Wisconsin, in the United States. Venustulus is one of the few synziphosurine genera with fossil showing evidence of appendages, the other ones being Weinbergina, Anderella and Camanchia. Despite often being aligned close to horseshoe crabs, it has been found that Venustulus and its relatives form a group made up of various basal euchelicerate arthropods more distant to the xiphosurans.

<i>Camanchia</i> Extinct genus of chelicerate

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.

References

  1. 1 2 3 4 5 6 7 8 Edgecombe, Gregory D. (1998-11-25). "Early myriapodous arthropods from Australia: Maldybulakia from the Devonian of New South Wales". Records of the Australian Museum. 50 (3): 293–313. doi: 10.3853/j.0067-1975.50.1998.1288 .
  2. 1 2 3 4 Tesakov, A.S.; Alexeev, A.S. (1992). "Myriapod-like arthropodes in the lower Devonian of the central Khazakhstan" (PDF). Paleontological Journal. 26: 18–23.
  3. 1 2 3 4 5 6 7 Zong, Ruiwen; Edgecombe, Gregory D.; Liu, Bingcai; Wang, Yi; Yin, Jiayi; Ma, Juan; Xu, Honghe (2023). Cherns, Lesley (ed.). "Silurian freshwater arthropod from northwest China". Papers in Palaeontology. 9 (2): e1488. doi:10.1002/spp2.1488. ISSN   2056-2799. S2CID   257843305.
  4. 1 2 Lamsdell, James C. (2013-01-01). "Revised systematics of Palaeozoic 'horseshoe crabs' and the myth of monophyletic Xiphosura". Zoological Journal of the Linnean Society. 167 (1): 1–27. doi: 10.1111/j.1096-3642.2012.00874.x . ISSN   0024-4082. S2CID   82434358.
  5. 1 2 Lamsdell, James C. (2020-09-01). "A chasmataspidid affinity for the putative xiphosuran Kiaeria Størmer, 1934". PalZ. 94 (3): 449–453. doi:10.1007/s12542-019-00493-8. ISSN   1867-6812. S2CID   207914022.
  6. 1 2 3 Bicknell, Russell D. C.; Pates, Stephen (2020). "Pictorial Atlas of Fossil and Extant Horseshoe Crabs, With Focus on Xiphosurida". Frontiers in Earth Science. 8. doi: 10.3389/feart.2020.00098 . ISSN   2296-6463.
  7. ↑ Tesakov, A.S.; Alexeev, A.S. (1998). "A New Name for Lophodesmus Tesakov and Alekseev, 1992 (Arthropoda)" (PDF). Paleontological Journal. 32: 49.
  8. ↑ Dunlop, J. A., Penney, D. & Jekel, D. 2020. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch , version 20.5
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