Carbotubulus is a genus of extinct worm belonging to the group Lobopodia and known from the Carboniferous Carbondale Formation of the Mazon Creek area in Illinois, US. A monotypic genus, it contains one species Carbotubulus waloszeki.[1] It was discovered and described by Joachim T. Haug, Georg Mayer, Carolin Haug, and Derek E.G. Briggs in 2012.[2] With an age of about 300 million years, it is the first long-legged lobopodian discovered after the period of Cambrian explosion.[3]
| Carbotubulus Temporal range:
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| (unranked): | Panarthropoda |
| Phylum: | †"Lobopodia" |
| Clade: | †Hallucishaniids |
| Family: | †Hallucigeniidae |
| Genus: | †Carbotubulus Haug et al., 2012[1] |
| Species: | †C. waloszeki
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| Binomial name | |
| †Carbotubulus waloszeki Haug et al., 2012
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Discovery and naming
editCarbotubulus, represented by a single fossil, was discovered by Joachim T. Haug (University of Greifswald, Germany), Georg Mayer (Leipzig University), Carolin Haug (Yale University, US), and Derek E.G. Briggs (Yale University) from the Carbondale Formation (Francis Creek Shale Member) of the Mazon Creek area in Illinois, US. It was recovered from the location named Pit 11 along with a fossil of an extinct velvet worm Helenodora inopinata (also mentioned as Ilyodes inopinata).[4] The original fossil is kept at the Royal Ontario Museum in Toronto.[1]
The name is derived from Latin words, carbo, referring to the geological age Carboniferous; and tubulus, meaning "small pipe", a description for the pipe-like legs. The specific name is after the German zoologist Dieter Waloszek, one of the leaders in the study of arthropod evolution.[1]
Description
editCarbotubulus is a soft-bodied worm with stumpy legs called lobopods. It has nine pairs of lobopods that are tube-like and elongated. Unlike other lobopodians, its head is relatively large and cylindrical in shape, occupying about one-third of the body length.[1] In other related hallucigeniid worms, the head is usually rounded and tiny such that it is often difficult to describe.[5][6][7] Living around 300 million years ago, it supports the fact that Cambrian-type worms survived for over 200 million years after extinction events during the Middle Cambrian (between 510 and 502 million years ago) by which most Cambrian animals disappeared.[8][9] Majority of the long-legged lobopodians such as Hallucigenia, Paucipodia and Orstenotubulus are known only during the Cambrian explosion.[10]
When Carbotubulus was first described, its systematic position was not clear and was loosely assigned to the phylum Arthropoda. Discovery of Cambrian lobopod Ovatiovermis cribratus from the Burgess Shale in 2017 led to a reanalysis of lobopodian classification, and Carbotubulus was assigned to a group Panarthropoda, specifically belonging to the family Hallucigeniidae along with the various species of Hallucigenia and Cardiodictyon catenulum.[11] This classification is still controversial, especially after the discovery of the second post-Cambrian (Silurian) long-legged lobopodian, Thanahita distos, from the Herefordshire Lagerstätte at the England–Wales border in UK in 2018. The new interpretation suggest that Carbotubulus and Cardiodictyon may lie outside the hallucigeniid family.[12]
References
edit- ^ a b c d e Haug, Joachim T.; Mayer, Georg; Haug, Carolin; Briggs, Derek E. G. (2012). "A Carboniferous Non-Onychophoran Lobopodian Reveals Long-Term Survival of a Cambrian Morphotype". Current Biology. 22 (18): 1673–1675. doi:10.1016/j.cub.2012.06.066. PMID 22885062.
- ^ "IRMNG taxon details: Carbotubulus". www.irmng.org. Archived from the original on 2022-01-14. Retrieved 2022-01-14.
- ^ Black, Riley (2012-08-17). "The Long-Lived Legacy of the Cambrian's "Wonderful Life"". National Geographic. Archived from the original on 2022-01-14. Retrieved 2022-01-14.
- ^ Murdock, Duncan J. E.; Gabbott, Sarah E.; Purnell, Mark A. (2016). "The impact of taphonomic data on phylogenetic resolution: Helenodora inopinata (Carboniferous, Mazon Creek Lagerstätte) and the onychophoran stem lineage". BMC Evolutionary Biology. 16: 19. doi:10.1186/s12862-016-0582-7. PMC 4722706. PMID 26801389.
- ^ Yang, Jie; Ortega-Hernández, Javier; Gerber, Sylvain; Butterfield, Nicholas J.; Hou, Jin-bo; Lan, Tian; Zhang, Xi-guang (2015). "A superarmored lobopodian from the Cambrian of China and early disparity in the evolution of Onychophora". Proceedings of the National Academy of Sciences. 112 (28): 8678–8683. Bibcode:2015PNAS..112.8678Y. doi:10.1073/pnas.1505596112. PMC 4507230. PMID 26124122.
- ^ Liu, JianNi; Shu, DeGan; Han, Jian; Zhang, ZhiFei (2008). "Comparative study of Cambrian lobopods Miraluolishania and Luolishania". Chinese Science Bulletin. 53 (1): 87–93. Bibcode:2008ChSBu..53...87L. doi:10.1007/s11434-007-0428-1. S2CID 128619311.
- ^ Ma, Xiaoya; Hou, Xianguang; Aldridge, Richard J.; Siveter, David J.; Siveter, Derek J.; Gabbott, Sarah E.; Purnell, Mark A.; Parker, Andrew R.; Edgecombe, Gregory D. (2012). "Morphology of Cambrian lobopodian eyes from the Chengjiang Lagerstätte and their evolutionary significance". Arthropod Structure & Development. 41 (5): 495–504. doi:10.1016/j.asd.2012.03.002. PMID 22484085.
- ^ Van Roy, Peter; Orr, Patrick J.; Botting, Joseph P.; Muir, Lucy A.; Vinther, Jakob; Lefebvre, Bertrand; Hariri, Khadija el; Briggs, Derek E. G. (2010). "Ordovician faunas of Burgess Shale type". Nature. 465 (7295): 215–218. doi:10.1038/nature09038. PMID 20463737. S2CID 4313285.
- ^ Seilacher, A. (1984). Holland, H. D.; Trendall, A. F. (eds.). "Late Precambrian and Early Cambrian Metazoa: Preservational or Real Extinctions?". Patterns of Change in Earth Evolution. Dahlem Workshop Reports Physical, Chemical, and Earth Sciences Research Reports. Berlin, Heidelberg: Springer: 159–168. doi:10.1007/978-3-642-69317-5_10. ISBN 978-3-642-69317-5.
- ^ Murdock, Duncan JE; Gabbott, Sarah E.; Mayer, Georg; Purnell, Mark A. (2014). "Decay of velvet worms (Onychophora), and bias in the fossil record of lobopodians". BMC Evolutionary Biology. 14 (1): 222. doi:10.1186/s12862-014-0222-z. PMC 4266977. PMID 25472836.
- ^ Caron, Jean-Bernard; Aria, Cédric (2017). "Cambrian suspension-feeding lobopodians and the early radiation of panarthropods". BMC Evolutionary Biology. 17 (1): 29. doi:10.1186/s12862-016-0858-y. PMC 5282736. PMID 28137244.
- ^ Siveter, Derek J.; Briggs, Derek E. G.; Siveter, David J.; Sutton, Mark D.; Legg, David (2018). "A three-dimensionally preserved lobopodian from the Herefordshire (Silurian) Lagerstätte, UK". Royal Society Open Science. 5 (8): 172101. doi:10.1098/rsos.172101. PMC 6124121. PMID 30224988.