| Markuelia Temporal range:
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|---|---|
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Scientific classification 
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| Kingdom: | Animalia |
| Total group: | Scalidophora |
| Genus: | †Markuelia Val’kov, 1983[1] |
| Type species | |
| †Markuelia secunda[1] Val’kov, 1984[1]
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| Other species[1][2][3] | |
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Markuelia is a genus of fossil worm-like bilaterian animals allied to Ecdysozoa and known from strata of Lower Cambrian to Lower Ordovician age containing five species.
An advanced X-ray imaging technique called X-ray tomographic microscopy has been applied to splendidly preserved, uncrushed Markuelia fossils found in Hunan province in southern China and in eastern Siberia.[4][5] When details in features smaller than one micrometre across can be observed, these fossils are seen to represent many developmental stages, from the first cell divisions to the time of hatching; therefore they offer a unique opportunity to study the development of Lower Cambrian animals.
The features observed indicate that the genus had a mouth surrounded by a ring of teeth, an alimentary canal, and an anus.
However the characters preserved are inconclusive regarding the genus' taxonomic affinity; it can at best be placed in the scalidophoran total group, since it is currently impossible to ally it with the priapulids or other members of the Scalidophora.[1]
References
[edit]- ^ a b c d e f Dong, X. -P.; Bengtson, S.; Gostling, N. J.; Cunningham, J. A.; Harvey, T. H. P.; Kouchinsky, A.; Val’Kov, A. K.; Repetski, J. E.; Stampanoni, M.; Marone, F.; Donoghue, P. C. J. (2010). "The anatomy, taphonomy, taxonomy and systematic affinity of Markuelia: Early Cambrian to Early Ordovician scalidophorans". Palaeontology. 53 (6): 1291–1314. Bibcode:2010Palgy..53.1291D. doi:10.1111/j.1475-4983.2010.01006.x. ISSN 1475-4983. S2CID 53483146.
- ^ Dong, Xi-ping; Duan, Baichuan; Liu, Jianbo; Donoghue, Philip C. J. (October 2022). "Internal anatomy of a fossilized embryonic stage of the Cambrian-Ordovician scalidophoran Markuelia". Royal Society Open Science. 9 (10). Bibcode:2022RSOS....920115D. doi:10.1098/rsos.220115. PMC 9532980. PMID 36249341. 220115.
- ^ Haug, Joachim; Maas, Andreas; Waloszek, Dieter; Donoghue, Philip C. J.; Bengtson, Stefan (September 2009). "A new species of Markuelia from the Middle Cambrian of Australia". Memoirs of the Association of Australasian Palaeontologists. 37: 303–313. ISSN 0810-8889. Retrieved 7 February 2026.
- ^ Donoghue, Philip C. J.; Bengtson, Stefan; Dong, Xi-ping; Gostling, Neil J.; Huldtgren, Therese; Cunningham, John A.; Yin, Chongyu; Yue, Zhao; Peng, Fan; Stampanoni, Marco (10 August 2006). "Synchrotron X-ray tomographic microscopy of fossil embryos". Nature. 442 (7103): 680–683. Bibcode:2006Natur.442..680D. doi:10.1038/nature04890. ISSN 0028-0836. PMID 16900198. Retrieved 17 December 2023.
- ^ "RelTime rates collapses to a strict clock when estimating the timeline of animal diversification". School of Biological Sciences, University of Bristol. 26 May 2017. Archived from the original on 12 August 2020.
Further reading
[edit]- Zhang, X. G.; Pratt, B. R.; Shen, C. (2011). "Embryonic Development of a Middle Cambrian (500 Myr Old) Scalidophoran Worm". Journal of Paleontology. 85 (5): 898. Bibcode:2011JPal...85..898Z. doi:10.1666/11-024.1. S2CID 85723012.
- Duan, B.; Dong, X. -P.; Donoghue, P. C. J. (2012). "New palaeoscolecid worms from the Furongian (upper Cambrian) of Hunan, South China: Is Markuelia an embryonic palaeoscolecid?". Palaeontology. 55 (3): 613. Bibcode:2012Palgy..55..613D. doi:10.1111/j.1475-4983.2012.01148.x. S2CID 53485143.
External links
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