Euthycarcinoidea

Euthycarcinoidea
Temporal range: Cambrian–Middle Triassic
Life restoration of Apankura
Life restoration of Sottyxerxes
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Clade: Mandibulata
Subclass: †Euthycarcinoidea
Gall & Grauvogel, 1964
Order: †Euthycarcinida
Gall & Grauvogel, 1964
Genera

See text

Euthycarcinoidea are an enigmatic group of extinct, possibly amphibious arthropods that ranged from Cambrian to Triassic times,[1] with the earliest known species being Apankura machu from the Cambrian and the youngest Euthycarcinus kessleri from the Middle Triassic.[2] Fossils are known from Europe, North America, Argentina, Australia, and Antarctica.

Description

The euthycarcinoid body was divided into a cephalon (head), preabdomen, and postabdomen. The cephalon consisted of two segments and included mandibles, antennae and presumed eyes. The preabdomen consisted of five to fourteen tergites, each having up to three somites. Each somite had in turn a pair of uniramous, segmented legs. The postabdomen was limbless and consisted of up to six segments and a terminal tail spine.[3]

Affinities

Due to its particular combination of characteristics, the position of the Euthycarcinoidea within the Arthropoda has been ambiguous; previous authors have allied euthycarcinoids with crustaceans (interpreted as copepods, branchiopods, or an independent group), with trilobites, or the merostomatans (horseshoe crabs and sea scorpions, now an obsolete group[4]).[5] However, due to the general features and the discovery of fossils from this group in Cambrian rocks, a 2010 study suggested that they may have given rise to the mandibulates, the group that includes the myriapods (centipedes, millipedes and the like), crustaceans, and hexapods (insects, etc.).[3]

However, a 2020 study identified several characters, including compound eyes and various details of the preoral chamber, that suggested instead a position as the closest relatives of living myriapods.[6] This would help to close the gap between the earliest body fossils of crown-group myriapods in the Silurian and molecular clock data suggesting a divergence from their closest relatives during the Ediacaran or Cambrian.[3] This had already been suggested by the cladogram of a previous study.[7]

The Cambrian euthycarcinoid Mosineia macnaughtoni from the Elk Mound Group, Blackberry Hill, central Wisconsin. Cambrian euthycarcinoids such as this one may have been the first animals to walk and survive on land.[8]

Environment and life habits

Euthycarcinoid fossils have been found in marine, brackish and freshwater deposits.[3] Taxa from the Cambrian are from marine or intertidal sediments, while all specimens from the Ordovician to the Triassic are freshwater or brackish.[5] Fossil impressions of euthycarcinoid postabdomens in association with Protichnites trackways in Cambrian intertidal/supratidal deposits also suggest that euthycarcinoids may have been the first arthropods to walk on land.[9][10] It has been suggested that the biofilms and microbial mats that covered much of the vast tidal flats during the Cambrian Period in North America may have provided the nourishment that lured these arthropods onto the land.[11] Fossil evidence also suggests the possibility that some euthycarcinoids came onto the land to lay and fertilize their eggs via amplexus, as do the modern horseshoe crabs.[10]

Classification

The known species of euthycarcinoids and their distribution were reviewed by Racheboeuf et al. in 2008. Additional species were described by Collette and Hagadorn in 2010.[5][9][12]

  • Family Euthycarcinidae Handlirsch, 1914
    • Genus Euthycarcinus Handlirsch, 1914
      • Species Euthycarcinus ibbenburensis Schultka, 1991 - Pennsylvanian: Westphalian, from freshwater deposits in Germany
      • Species Euthycarcinus kessleri Handlirsch, 1914 - Triassic, from freshwater deposits in France
      • Species Euthycarcinus martensi Schneider, 1983 - Permian, from freshwater deposits in Germany
    • Genus Synaustrus Riek, 1964
      • Species Synaustrus brookvalensis Riek, 1964 - Triassic, from freshwater deposits of Australia
  • Family Kottixerxidae Starobogatov, 1988
    • Genus Heterocrania Hirst & Maulik, 1926
      • Species Heterocrania rhyniensis Hirst & Maulik, 1926 - Lower Devonian, from freshwater deposits of the United Kingdom[13]
    • Genus Kalbarria McNamara & Trewin, 1993
      • Species Kalbarria brimmellae McNamara & Trewin, 1993 - Ordovician or Late Silurian, from freshwater deposits of Australia (age and habitat are controversial)[14]
    • Genus Kottixerxes Schram, 1971
      • Species Kottixerxes anglicus Wilson & Almond, 2001 - Pennsylvanian: Westphalian, from brackish to freshwater deposits of the United Kingdom
      • Species Kottyxerxes gloriosus Schram, 1971 - Pennsylvanian: Westphalian, from brackish to freshwater deposits of the United States
    • Genus Schramixerxes Starobogatov, 1988
      • Species Schramixerxes gerem (Schram & Rolfe, 1982) - Late Pennsylvanian: Stephanian stage, from freshwater deposits in France
    • Genus Smithixerxes Schram & Rolfe, 1982
      • Species Smithixerxes juliarum Schram & Rolfe, 1982 - Pennsylvanian: Westphalian, from brackish to freshwater deposits of the United States
      • Species Smithixerxes pustulosus Wilson & Almond, 2001 - Pennsylvanian: Westphalian, from brackish to freshwater deposits of the United Kingdom
  • Family Mictomeridae Collette & Hagadorn, 2010[9]
    • Genus Mictomerus Collette & Hagadorn, 2010[9]
      • Species Mictomerus melochevillensis Collette & Hagadorn, 2010[9] - Cambrian, from intertidal deposits in Canada
  • Family incertae sedis
    • Genus Antarcticarcinus Collette, Isbell & Miller, 2017[15]
      • Species Antarcticarcinus pagoda Collette, Isbell & Miller, 2017[15] - Upper Carboniferous to Lower Permian, Pagoda Formation Antarctica.[15]
    • Genus Apankura Vaccari, Edgecombe & Escudero, 2004[16]
      • Species Apankura machu Vaccari, Edgecombe & Escudero, 2004[16] - Cambrian, from marine deposits in Argentina
    • Genus Ericixerxes Gueriau, Lamsdell, Wogelius, Manning, Egerton, Bergmann, Bertrand & Denayer, 2020
      • Species Ericixerxes potii Gueriau, Lamsdell, Wogelius, Manning, Egerton, Bergmann, Bertrand & Denayer, 2020 - Upper Devonian, from brackish deposits in Belgium
    • Genus Mosineia Collette & Hagadorn, 2010[9]
      • Species Mosineia macnaughtoni Collette & Hagadorn, 2010[9] - Cambrian, from intertidal deposits in the United States
    • Genus Pieckoxerxes Starobogatov, 1988
      • Species Pieckoxerxes pieckoae (Schram & Rolfe, 1982) - Pennsylvanian: Westphalian, from brackish to freshwater deposits of the United States
    • Genus Sottyxerxes Schram & Rolfe, 1982
      • Species Sottyxerxes multiplex Schram & Rolfe, 1982 - Late Pennsylvanian: Stephanian stage, from freshwater deposits in France

References

  1. ^ A new Devonian euthycarcinoid reveals the use of different respiratory strategies during the marine-to-terrestrial transition in the myriapod lineage
  2. ^ Euthycarcinoids - Ortega-Hernández - 2010 - Geology Today
  3. ^ a b c d Ortega-Hernández, Javier; Legg, David A.; Tremewan, Jonathan; Braddy, Simon J. (2010). "Euthycarcinoids". Geology Today. 26 (5): 195–198. doi:10.1111/j.1365-2451.2010.00770.x. ISSN 1365-2451.
  4. ^ Lamsdell, James C. (2012-12-18). "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.
  5. ^ a b c Racheboeuf, Patrick R.; Vannier, Jean; Schram, Frederick R.; Chabard, Dominique; Sotty, Daniel (2008). "The euthycarcinoid arthropods from Montceau-les-Mines, France: functional morphology and affinities" (PDF). Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 99 (1): 11–25. doi:10.1017/S1755691008006130. S2CID 59123727.
  6. ^ Edgecombe, Gregory D.; Strullu-Derrien, Christine; Góral, Tomasz; Hetherington, Alexander J.; Thompson, Christine; Koch, Marcus (2020). "Aquatic stem group myriapods close a gap between molecular divergence dates and terrestrial fossil record". Proceedings of the National Academy of Sciences. 117 (16): 8966–8972. doi:10.1073/pnas.1920733117. PMC 7183169. PMID 32253305. S2CID 215408474.
  7. ^ Vannier, Jean; Aria, Cédric; Taylor, Rod S.; Caron, Jean-Bernard (June 2018). "Waptia fieldensis Walcott, a mandibulate arthropod from the middle Cambrian Burgess Shale". Royal Society Open Science. 5 (6) 172206. doi:10.1098/rsos.172206. ISSN 2054-5703. PMC 6030330. PMID 30110460.
  8. ^ McNamara, Kenneth J.; Trewin, Nigel H. (1993). "A euthycarcinoid arthropod from the Silurian of Western Australia". Palaeontology. 36: 319–335.
  9. ^ a b c d e f g Collette, Joseph H.; Hagadorn, James W. (July 2010). "Three-dimensionally preserved arthropods from Cambrian Lagerstätten of Quebec and Wisconsin". Journal of Paleontology. 84 (4): 646–667. doi:10.1666/09-075.1. ISSN 0022-3360.
  10. ^ a b Collette, Joseph H.; Gass, Kenneth C.; Hagadorn, James W. (May 2012). "Protichnites eremita unshelled? Experimental model-based neoichnology and new evidence for a euthycarcinoid affinity for this ichnospecies". Journal of Paleontology. 86 (3): 442–454. doi:10.1666/11-056.1. ISSN 0022-3360.
  11. ^ MacNaughton, Robert B.; Cole, Jennifer M.; Dalrymple, Robert W.; Braddy, Simon J.; Briggs, Derek E.G.; Lukie, Terrence D. (2002). "First steps on land: Arthropod trackways in Cambrian-Ordovician eolian sandstone, southeastern Ontario, Canada". Geology. 30 (5): 391. doi:10.1130/0091-7613(2002)030<0391:FSOLAT>2.0.CO;2. ISSN 0091-7613.
  12. ^ "Euthycarcinoidea". Catalogue of Life. Species 2000: Leiden, the Netherlands. Retrieved 14 January 2026.
  13. ^ Anderson, Lyall I.; Trewin, Nigel H. (2003). "An Early Devonian arthropod fauna from the Windyfield cherts, Aberdeenshire, Scotland". Palaeontology. 46 (3): 467–509. doi:10.1111/1475-4983.00308. ISSN 1475-4983.
  14. ^ "Terrestrialization in the Ordovician". Geological Society, London, Special Publications. doi:10.1144/sp532-2022-92. Retrieved 2022-11-14.
  15. ^ a b c Collette, Joseph H.; Isbell, John L.; Miller, Molly F. (September 2017). "A unique winged euthycarcinoid from the Permian of Antarctica". Journal of Paleontology. 91 (5): 987–993. doi:10.1017/jpa.2017.28. ISSN 0022-3360.
  16. ^ a b Vaccari, N. E.; Edgecombe, G. D.; Escudero, C. (July 2004). "Cambrian origins and affinities of an enigmatic fossil group of arthropods". Nature. 430 (6999): 554–557. doi:10.1038/nature02705. ISSN 1476-4687.
allikas: http://en.wikipedia.org/wiki/Euthycarcinoidea