Cucumericrus
Cucumericrus
Extinct genus of arthropod
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]
| Cucumericrus | |
|---|---|
| Trunk appengae of Cucumericrus decoratus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Stem group: | Arthropoda |
| Genus: | †Cucumericrus Hou, Bergstrom & Ahlberg, 1995 |
| Type species | |
| Cucumericrus decoratus Hou, Bergstrom & Ahlberg, 1995 | |
Cucumericrus known from a few poorly preserved specimens.[1][2] Only fragments of trunk cuticle and corresponded appendages had been revealed, while important taxonomic features such as head structures 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]
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]
- Caryosyntrips, another stem-arthropod with similar uncertainties.
- Parapeytoia, a megacheiran once thought to be similarly leg-bearing radiodont.
- Erratus, a basal deuteropod with similar component of trunk appendages.
- 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.
- 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.
- 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.
- Jan Bergström & Hou Xian-Guang (2003). "Arthropod origins" (PDF). Bulletin of Geosciences. 78 (4): 323–334.
- 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.
- 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.
- 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.
- 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. doi:10.1038/ncomms3485. ISSN 2041-1723. PMID 24077329.
- 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. doi:10.1186/s12862-019-1560-7. ISSN 1471-2148. PMC 6950928. PMID 31914921.
- 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.
- 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.
- 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. doi:10.1017/jpa.2023.63. ISSN 0022-3360. S2CID 266292707.
