Biology:Megadictyon

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Short description: Extinct genus of Cambrian lobopodian


Megadictyon
Temporal range: Cambrian Stage 3
20191118 Megadictyon cf. haikouensis.png
Reconstruction of Megadictyon cf. haikouensis
Scientific classification
Kingdom:
Phylum:
Class:
†Xenusia
Order:
†Siberiida
Family:
†Siberiidae
Genus:
Megadictyon
Luo & Hu, 1999
Species:
M. haikouensis Luo & Hu, 1999

Megadictyon is a genus of Cambrian lobopodian with similarities to Jianshanopodia and Siberion. Occasionally mis-spelt Magadictyon.[1]

Description

Megadictyon is a large lobopodian, with a body length (excluding appendages) possibly up to 20 centimeters in total.[2] The head has a pair of robust frontal appendages[3] associated with rows of spines and terminal claws.[2] Located on the underside of the head is a radiodont-like mouthpart formed by multiple layers of plates and tooth-like structures.[2] The trunk is wide and annulated, with a pair of well-developed lobopodous limbs on each body segment. Only 8 segment/limb pairs are countable in the incomplete fossil materials which are lacking the posterior region, so it may have had more (possibly up to 11 to 13) in nature.[2] It also has pairs of digestive glands similar to those of basal arthropods.[2][4]

Phylogeny

Phylogenetic position of Megadictyon according to Pates et al. (2022).[5]

Aysheaia

Onychodictyon

Tardigrada

Onychophora

Megadictyon

Jianshanopodia

Hadranax

Kerygmachela

Pambdelurion

Utaurora

Opabinia

Aegirocassis

Peytoia

Schinderhannes bartelsi

Cambroraster

Hurdia

Amplectobelua

Lyrarapax

Anomalocaris

Houcaris

Deuteropoda

References

  1. "Corrigendum". Acta Zoologica 89 (2): 183. 2007. doi:10.1111/j.1463-6395.2007.00307.x. https://onlinelibrary.wiley.com/doi/10.1111/j.1463-6395.2007.00307.x. 
  2. 2.0 2.1 2.2 2.3 2.4 Liu, J.-N.; Shu, D.-G.; Han, J.; Zhang, Z.-F.; Zhang, X.-L. (2007). "Morpho-anatomy of the lobopod Magadictyon cf. haikouensis from the Early Cambrian Chengjiang Lagerstätte, South China". Acta Zoologica 88: 279–288. doi:10.1111/j.1463-6395.2007.00281.x. 
  3. Liu, J.-N.; Shu, D.-G.; Han, J.; Zhang, Z.-F.; Zhang, X. (2008). "Origin, diversification, and relationships of Cambrian lobopods". Gondwana Research 14 (1–2): 277–283. doi:10.1016/j.gr.2007.10.001. Bibcode2008GondR..14..277L. 
  4. Vannier, Jean; Liu, Jianni; Lerosey-Aubril, Rudy; Vinther, Jakob; Daley, Allison C (2014). "Sophisticated digestive systems in early arthropods". Nature Communications 5: 3641. doi:10.1038/ncomms4641. PMID 24785191. Bibcode2014NatCo...5.3641V. 
  5. Pates, Stephen; Wolfe, Joanna M.; Lerosey-Aubril, Rudy; Daley, Allison C.; Ortega-Hernández, Javier (2022-02-09). "New opabiniid diversifies the weirdest wonders of the euarthropod stem group". Proceedings of the Royal Society B: Biological Sciences 289 (1968). doi:10.1098/rspb.2021.2093. PMID 35135344. 

Wikidata ☰ Q48968954 entry