Cucumericrus

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Cucumericrus
Temporal range: Miaolingian–Middle Cambrian
20210207 Cucumericrus decoratus trunk appendage.png
Trunk appengade of Cucumericrus decoratus
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Stem group: Arthropoda
Genus: Cucumericrus
Hou, Bergstrom & Ahlberg, 1995
Type species
Cucumericrus decoratus
Hou, Bergstrom & Ahlberg, 1995

Cucumericrus ("cucumber-leg") is an extinct genus of stem-arthropod. The type and only species is Cucumericrus decoratus, with fossils discovered from the Maotianshan Shales of Yunnan, China. [1]

Contents

Description

Cucumericrus is known from a few poorly preserved specimens. [1] [2] Only fragments of trunk cuticle and corresponding appendages had been revealed, while features, such as head structures, which are important to determining its taxonomy, are unknown. [2] [3] The trunk cuticle possess irregular wrinkles [1] and may had been soft in life. [4] Each of the trunk appendage compose of a dorsal flap-like element and a ventral stubby leg with unknown distal region, [1] structurally comparable to the trunk appendages of gill lobopodians (dorsal flaps and ventral lobopods) and euarthropod biramous appendages (flap-like exopod and limb-like endopod). [3] [5] Anterior margin of the flap lined with ray-like structures, similar to the body flaps of some radiodonts. The legs have been interpreted as somewhere between annulated lobopod legs and segmented arthropod legs. [4] [5]

Taxonomic affinities

Cucumericrus was originally described as a radiodont alongside Parapeytoia , a genus with somewhat similar trunk appendages, but later revealed to be a megacheiran [6] [7] [8] [9] being misinterpreted as a leg-bearing radiodont at that time. [1] The radiodont affinity of Cucumericrus remain questionable, since the presence of legs is unknown from any other radiodonts and no other radiodont key features (e.g. frontal appendages; oral cone; head sclerites) had been discovered. Only a few phylogenetic analysis including Cucumericrus, either resolving it in a polytomy between euarthropods and other radiodonts (alongside Caryosyntrips ) [10] [11] or closer to euarthropods (as a basal deuteropod) than radiodonts. [12]

See also

References

  1. 1 2 3 4 5 Xian-Guang, Hou; Bergström, Jan; Ahlberg, Per (1995-09-01). "Anomalocaris and other large animals in the lower Cambrian Chengjiang fauna of southwest China" . GFF. 117 (3): 163–183. Bibcode:1995GFF...117..163X. doi:10.1080/11035899509546213. ISSN   1103-5897.
  2. 1 2 Allison C. Daley & Graham E. Budd (2010). "New anomalocaridid appendages from the Burgess Shale, Canada". Palaeontology . 53 (4): 721–738. Bibcode:2010Palgy..53..721D. doi: 10.1111/j.1475-4983.2010.00955.x .
  3. 1 2 Xian-Guang, Hou; Siveter, David J.; Siveter, Derek J.; Aldridge, Richard J.; Pei-Yun, Cong; Gabbott, Sarah E.; Xiao-Ya, Ma; Purnell, Mark A.; Williams, Mark (2017-04-24). The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life. John Wiley & Sons. ISBN   978-1-118-89638-9.
  4. 1 2 Jan Bergström & Hou Xian-Guang (2003). "Arthropod origins" (PDF). Bulletin of Geosciences . 78 (4): 323–334.
  5. 1 2 Van Roy, Peter; Daley, Allison C.; Briggs, Derek E. G. (2015). "Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps" . Nature. 522 (7554): 77–80. Bibcode:2015Natur.522...77V. doi:10.1038/nature14256. ISSN   1476-4687. PMID   25762145. S2CID   205242881.
  6. Stein, Martin (2010). "A new arthropod from the Early Cambrian of North Greenland, with a 'great appendage'-like antennula: A NEW CAMBRIAN ARTHROPOD FROM GREENLAND" . Zoological Journal of the Linnean Society. 158 (3): 477–500. doi:10.1111/j.1096-3642.2009.00562.x.
  7. Legg, David A.; Sutton, Mark D.; Edgecombe, Gregory D.; Caron, Jean-Bernard (2012-12-07). "Cambrian bivalved arthropod reveals origin of arthrodization". Proceedings of the Royal Society B: Biological Sciences. 279 (1748): 4699–4704. doi:10.1098/rspb.2012.1958. ISSN   0962-8452. PMC   3497099 . PMID   23055069.
  8. Legg, David A.; Sutton, Mark D.; Edgecombe, Gregory D. (2013-09-30). "Arthropod fossil data increase congruence of morphological and molecular phylogenies". Nature Communications. 4 (1): 2485. Bibcode:2013NatCo...4.2485L. doi:10.1038/ncomms3485. ISSN   2041-1723. PMID   24077329.
  9. Aria, Cédric; Zhao, Fangchen; Zeng, Han; Guo, Jin; Zhu, Maoyan (2020-01-08). "Fossils from South China redefine the ancestral euarthropod body plan". BMC Evolutionary Biology. 20 (1): 4. Bibcode:2020BMCEE..20....4A. doi: 10.1186/s12862-019-1560-7 . ISSN   1471-2148. PMC   6950928 . PMID   31914921.
  10. Van Roy, Peter; Daley, Allison C.; Briggs, Derek E. G. (2015). "Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps" . Nature. 522 (7554): 77–80. Bibcode:2015Natur.522...77V. doi:10.1038/nature14256. ISSN   1476-4687. PMID   25762145. S2CID   205242881.
  11. Liu, Jianni; Lerosey-Aubril, Rudy; Steiner, Michael; Dunlop, Jason A; Shu, Degan; Paterson, John R (2018-11-01). "Origin of raptorial feeding in juvenile euarthropods revealed by a Cambrian radiodontan". National Science Review. 5 (6): 863–869. doi: 10.1093/nsr/nwy057 . ISSN   2095-5138.
  12. McCall, Christian R. A. (2023-12-13). "A large pelagic lobopodian from the Cambrian Pioche Shale of Nevada" . Journal of Paleontology. 97 (5): 1009–1024. Bibcode:2023JPal...97.1009M. doi:10.1017/jpa.2023.63. ISSN   0022-3360. S2CID   266292707.