Cheloniellon range about 20 centimeters in body length (excluding appendages).[1] The flattened, ovoid body compose of 11 tergites (dorsal exoskeleton), all but the posteriormost are laterally expanded and covered the appendages underneath each of them. The boundaries between tergites have a radiated appearance. Dorsal surface of the first tergite have a pair of kidney-shaped eyes.[1] Based on the differentiation of corresponding appendages, the first 2 tergites and the remaining 9 tergites were interpreted as those of cephalon (head) and trunk, respectively.[1] Contray to the widely-referred reconstruction by Stürmer & Bergström (1978),[1] but as most of the Cheloniellids, There is no evidence of telson (a medial tail-like terminal structure) in any described fossil materials.[2]
Ventral structures of the anterior region of Cheloniellon calmani, showing all cephalic appendages and first two trunk appendage pairs. Dark grey (first diagram) and coloured region (second diagram): appendicular structures, Ant (yellow): antenna, Pap (green): 2nd cephalic appendage, Est: esthetasc-like brush, Lbr (red): labrum, Gap (cyan): gnathobasic appendage, Gn: gnathobase, Tap (blue): trunk appendage, Ex: exopod, Te: tergite.
Underneath the tergites were numerous pairs of appendages. The anteriormost appendage pair were antennae, followed by a pair of specialized second appendages that bore spines and esthetasc-like brushes, and 4 pairs of leg-like appendages that have overlapped gnathobases (jaw-like structure on leg base).[1] The mouth was covered by a labrum with spiny surface, situated between the second appendages and the first gnathobasic appendages.[1] The last gnathobasic appendage pair and the remaining 5 appendage pairs anterior to it were interpreted as corresponding to the second tergite and first tergite, respectively.[1] Appendages posterior to the cephalon were 8 pairs of biramous appendages (each compose of a leg-like endopod and a lobe-like exopod) and a pair of furcae, corresponding to the remaining 9 trunk tergites.[1]
Paleoecologyedit
Cheloniellon may have been a benthicpredator,[3] using its gnathobases to crush prey while the spiny labrum may have helped lead food items toward the mouth opening.[1] The specialized second appendages are too fragile to be raptorial, instead they may have played a tactile role, sensing the property and position of food items.[1] The endopod and exopod of the trunk appendages may have had a locomotory and respiratory function, respectively.[1][2]
Cheloniellon is a genus of Cheloniellida, an extinct arthropod taxon that have a controversial phylogenetic position. It was previously thought to be chelicerate-related,[1][2] but later studies repeatedly suggests it as a member of Artiopoda, forming the clade Vicissicaudata with Aglaspidida and related genera.[4][5][6] Within Cheloniellida, Cheloniellon branched next to Neostrabops but basal to Triopus and Duslia.[4][5]
Referencesedit
^ abcdefghijklmStürmer, Wilhelm; Bergström, Jan (1978-06-01). "The arthropod Cheloniellon from the devonian hunsrück shale". Paläontologische Zeitschrift. 52 (1): 57–81. doi:10.1007/BF03006730. S2CID 87725308.
^ abcWendruff, Andrew James, et al. "New cheloniellid arthropod with large raptorial appendages from the Silurian of Wisconsin, USA." BioRxiv (2018): 407379. [1]
^Rust, Jes; Bergmann, Alexandra; Bartels, Christoph; Schoenemann, Brigitte; Sedlmeier, Stephanie; Kühl, Gabriele (2016-03-01). "The Hunsrück biota: A unique window into the ecology of Lower Devonian arthropods". Arthropod Structure & Development. Special Issue: Fossils as Living Beings. 45 (2): 140–151. doi:10.1016/j.asd.2016.01.004. ISSN 1467-8039. PMID 26826500.
^ abcOrtega‐Hernández, Javier; Legg, David A.; Braddy, Simon J. (2013). "The phylogeny of aglaspidid arthropods and the internal relationships within Artiopoda". Cladistics. 29 (1): 15–45. doi:10.1111/j.1096-0031.2012.00413.x. ISSN 1096-0031. PMID 34814371. S2CID 85744103.
^ abcLerosey-Aubril, Rudy; Zhu, Xuejian; Ortega-Hernández, Javier (2017-09-11). "The Vicissicaudata revisited – insights from a new aglaspidid arthropod with caudal appendages from the Furongian of China". Scientific Reports. 7 (1): 11117. doi:10.1038/s41598-017-11610-5. ISSN 2045-2322. PMC5593897. PMID 28894246.
^Du, Kun‐sheng; Ortega‐Hernández, Javier; Yang, Jie; Zhang, Xi‐guang (2019–2020). "A soft‐bodied euarthropod from the early Cambrian Xiaoshiba Lagerstätte of China supports a new clade of basal artiopodans with dorsal ecdysial sutures". Cladistics. 35 (3): 269–281. doi:10.1111/cla.12344. ISSN 0748-3007. PMID 34622993. S2CID 89985331.
January 01, 1970
cheloniellon, monotypic, genus, cheloniellid, arthropod, known, only, species, calmani, discovered, from, lower, devonian, hunsrück, slate, germany, temporal, range, lower, devonian, preꞒ, reconstruction, calmani, scientific, classification, kingdom, animalia,. Cheloniellon is a monotypic genus of cheloniellid arthropod known only by one species Cheloniellon calmani discovered from the Lower Devonian Hunsruck Slate of Germany 1 CheloniellonTemporal range Lower Devonian PreꞒ Ꞓ O S D C P T J K Pg N Reconstruction of Cheloniellon calmani Scientific classification Kingdom Animalia Phylum Arthropoda Superclass Vicissicaudata Order Cheloniellida Family Cheloniellidae Genus CheloniellonBroili 1932 Species Cheloniellon calmani Broili 1932 Contents 1 Morphology 2 Paleoecology 3 Classification 4 ReferencesMorphology editCheloniellon range about 20 centimeters in body length excluding appendages 1 The flattened ovoid body compose of 11 tergites dorsal exoskeleton all but the posteriormost are laterally expanded and covered the appendages underneath each of them The boundaries between tergites have a radiated appearance Dorsal surface of the first tergite have a pair of kidney shaped eyes 1 Based on the differentiation of corresponding appendages the first 2 tergites and the remaining 9 tergites were interpreted as those of cephalon head and trunk respectively 1 Contray to the widely referred reconstruction by Sturmer amp Bergstrom 1978 1 but as most of the Cheloniellids There is no evidence of telson a medial tail like terminal structure in any described fossil materials 2 nbsp nbsp Ventral structures of the anterior region of Cheloniellon calmani showing all cephalic appendages and first two trunk appendage pairs Dark grey first diagram and coloured region second diagram appendicular structures Ant yellow antenna Pap green 2nd cephalic appendage Est esthetasc like brush Lbr red labrum Gap cyan gnathobasic appendage Gn gnathobase Tap blue trunk appendage Ex exopod Te tergite Underneath the tergites were numerous pairs of appendages The anteriormost appendage pair were antennae followed by a pair of specialized second appendages that bore spines and esthetasc like brushes and 4 pairs of leg like appendages that have overlapped gnathobases jaw like structure on leg base 1 The mouth was covered by a labrum with spiny surface situated between the second appendages and the first gnathobasic appendages 1 The last gnathobasic appendage pair and the remaining 5 appendage pairs anterior to it were interpreted as corresponding to the second tergite and first tergite respectively 1 Appendages posterior to the cephalon were 8 pairs of biramous appendages each compose of a leg like endopod and a lobe like exopod and a pair of furcae corresponding to the remaining 9 trunk tergites 1 Paleoecology editCheloniellon may have been a benthic predator 3 using its gnathobases to crush prey while the spiny labrum may have helped lead food items toward the mouth opening 1 The specialized second appendages are too fragile to be raptorial instead they may have played a tactile role sensing the property and position of food items 1 The endopod and exopod of the trunk appendages may have had a locomotory and respiratory function respectively 1 2 Classification editCheloniellida Neostrabops Cheloniellon Triopus Duslia Phylogenetic position of Cheloniellon 4 5 Cheloniellon is a genus of Cheloniellida an extinct arthropod taxon that have a controversial phylogenetic position It was previously thought to be chelicerate related 1 2 but later studies repeatedly suggests it as a member of Artiopoda forming the clade Vicissicaudata with Aglaspidida and related genera 4 5 6 Within Cheloniellida Cheloniellon branched next to Neostrabops but basal to Triopus and Duslia 4 5 References edit a b c d e f g h i j k l m Sturmer Wilhelm Bergstrom Jan 1978 06 01 The arthropod Cheloniellon from the devonian hunsruck shale Palaontologische Zeitschrift 52 1 57 81 doi 10 1007 BF03006730 S2CID 87725308 a b c Wendruff Andrew James et al New cheloniellid arthropod with large raptorial appendages from the Silurian of Wisconsin USA BioRxiv 2018 407379 1 Rust Jes Bergmann Alexandra Bartels Christoph Schoenemann Brigitte Sedlmeier Stephanie Kuhl Gabriele 2016 03 01 The Hunsruck biota A unique window into the ecology of Lower Devonian arthropods Arthropod Structure amp Development Special Issue Fossils as Living Beings 45 2 140 151 doi 10 1016 j asd 2016 01 004 ISSN 1467 8039 PMID 26826500 a b c Ortega Hernandez Javier Legg David A Braddy Simon J 2013 The phylogeny of aglaspidid arthropods and the internal relationships within Artiopoda Cladistics 29 1 15 45 doi 10 1111 j 1096 0031 2012 00413 x ISSN 1096 0031 PMID 34814371 S2CID 85744103 a b c Lerosey Aubril Rudy Zhu Xuejian Ortega Hernandez Javier 2017 09 11 The Vicissicaudata revisited insights from a new aglaspidid arthropod with caudal appendages from the Furongian of China Scientific Reports 7 1 11117 doi 10 1038 s41598 017 11610 5 ISSN 2045 2322 PMC 5593897 PMID 28894246 Du Kun sheng Ortega Hernandez Javier Yang Jie Zhang Xi guang 2019 2020 A soft bodied euarthropod from the early Cambrian Xiaoshiba Lagerstatte of China supports a new clade of basal artiopodans with dorsal ecdysial sutures Cladistics 35 3 269 281 doi 10 1111 cla 12344 ISSN 0748 3007 PMID 34622993 S2CID 89985331 Retrieved from https en wikipedia org w index php title Cheloniellon amp oldid 1193827121, wikipedia, wiki, book, books, library,
