Editing Microdictyon (section)

== Ecology ==
''Microdictyon'' was [[epibenthic]], walking along the seafloor using is [[Lobopodia|lobopodous]] limbs. The anterior portion of the body was the most flexible - fossils showing ''Microdictyon'' strongly curled up indicate that the cause of death was [[Anoxic waters|anoxia]], inferred from studies on modern [[Arthropod|arthropods]] and [[Annelid|annelids]].<ref name="junyuan1995" /> The claws of ''Microdictyon'' are not particularly suited for walking on muddy substrate, but rather for climbing or grabbing — it was once proposed that, based on frequent association with fossils of ''[[Eldonia]]'', and a presumed [[Pelagic zone|pelagic]] lifestyle for the [[jellyfish]]-like ''Eldonia'', that ''Microdictyon'' would use its claws to grab onto the large disc-shaped animal as it swam in order to feed on it. However, ''Eldonia'' is no longer thought to be pelagic, and probably lived gregariously on the seafloor. The frequent association with ''Microdictyon'' still likely indicates an ecological link, with ''Microdictyon'' possibly using its claws to feed on ''Eldonia'' or other carcasses — a similar relationship has been proposed for ''[[Paucipodia]]''. ''Paucipodia'' and ''Microdictyon'' have also been found preserved alongside mass concentrations of living, dead, and decaying ''[[Cricocosmia]]'' worms.<ref name="vannier2017">{{cite journal |last1=Vannier |first1=Jean |last2=Martin |first2=Emmanuel L. O. |title=Worm-lobopodian assemblages from the Early Cambrian Chengjiang biota: Insight into the “pre-arthropodan ecology”? |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |date=15 February 2017 |volume=468 |pages=373–387 |doi=10.1016/j.palaeo.2016.12.002 |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018216308136 |issn=0031-0182}}</ref>

[[File:Secondarily phosphatized cuticular plates in Microdictyon sp. from the early Cambrian Xinji Formation, Shuiyu section, Shanxi Province, China.png|thumb|right|''Microdictyon'' sclerite plates from the Cambrian Xinji Formation.<ref name="chen2024" />]]

The purpose and development of ''Microdictyon'''s sclerotized plates remains a subject of debate. Some authors, beginning with Jerzy Dzik in 2003,<ref name="dzik2003">{{cite journal |last1=Dzik |first1=Jerzy |title=Early Cambrian lobopodian sclerites and associated fossils from Kazakhstan |journal=Palaeontology |date=2003 |volume=46 |issue=1 |pages=93–112 |doi=10.1111/1475-4983.00289 |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/1475-4983.00289 |language=en |issn=1475-4983}}</ref> propose that based on a similar proposed method of sclerite growth and a similar morphology, these sclerites could be interpreted as large [[Compound eye|compound eyes]], similar to [[Phacopida|phacopid trilobites]]<ref name="eyessssss">{{cite journal |last1=Schoenemann |first1=Brigitte |last2=Clarkson |first2=Euan N. K. |title=The median eyes of trilobites |journal=Scientific Reports |date=8 March 2023 |volume=13 |issue=1 |pages=3917 |doi=10.1038/s41598-023-31089-7 |url=https://www.nature.com/articles/s41598-023-31089-7 |language=en |issn=2045-2322|pmc=9995485 }}</ref> — this idea has been widely rejected.<ref name="Zhang2007">{{Cite journal | last1 = Zhang | first1 = X. -G. | last2 = Aldridge | first2 = R. J. | doi = 10.1111/j.1475-4983.2006.00634.x | title = Development and Diversification of Trunk Plates of the Lower Cambrian Lobopodians | journal = Palaeontology | volume = 50 | issue = 2 | pages = 401 | year = 2007 | bibcode = 2007Palgy..50..401Z | s2cid = 85293118 | doi-access = free }}</ref> The other proposals, that being defense and or muscle attachment, are viewed as much more plausible. Evidence from a small number of specimens, including both complete fossils from the Chengjiang as well as isolated microfossil plates, indicate that ''Microdictyon'' and other eoconchariids [[Ecdysis|moulted]] their plates asynchronously, with the new, larger plates forming beneath the old ones, starting with the plates in the middle of the body and spreading to the anterior and posterior plates later. The new plates were not formed all at once, and the old plates remained overtop of the new ones for some time before the moult was completed, with the old cuticle rupturing along the dorsal surface, and the animal emerging with already hardened plates.<ref name="zhang2007" /><ref name="dzik2003" /><ref name="chen2024" /> This is similar to the biphasic moulting of modern [[Isopoda|isopods]] (the posterior half of the body moults first, followed later by the anterior half), as opposed to most [[Crustacean|crustaceans]], which moult their entire exoskeleton in a single step.<ref name="chen2024">{{cite journal |last1=Chen |first1=Ailin |last2=Vannier |first2=Jean |last3=Guo |first3=Jin |last4=Wang |first4=Deng |last5=Gąsiorek |first5=Piotr |last6=Han |first6=Jian |last7=Ma |first7=Wenjiao |title=Molting in early Cambrian armored lobopodians |journal=Communications Biology |date=5 July 2024 |volume=7 |issue=1 |pages=1–10 |doi=10.1038/s42003-024-06440-x |url=https://www.nature.com/articles/s42003-024-06440-x |language=en |issn=2399-3642}}</ref>