Editing Lobopodia (section)

=== Internal structures ===

[[File:Jianshanopodia decora.jpg|thumb|Fossilized posterior trunk region of ''[[Jianshanopodia]] decora'', showing traces of lobopods, gut diverculae and lobe-like terminal extension.]]

The gut of lobopodians is often straight, undifferentiated,<ref name=":5">{{Cite journal|last1=Vannier|first1=Jean|last2=Liu|first2=Jianni|last3=Lerosey-Aubril|first3=Rudy|last4=Vinther|first4=Jakob|last5=Daley|first5=Allison C.|date=2014-05-02|title=Sophisticated digestive systems in early arthropods|journal=Nature Communications|language=en|volume=5|issue=1|pages=3641|doi=10.1038/ncomms4641|pmid=24785191|issn=2041-1723|bibcode=2014NatCo...5.3641V|doi-access=free}}</ref> and sometimes preserved in the fossil record in three dimensions. In some specimens the gut is found to be filled with sediment.<ref name="Hou2004">{{cite journal|author=Hou, Xian-Guang|last2=Ma|first2=Xiao-Ya|last3=Zhao|first3=Jie|last4=Bergström|first4=Jan|year=2004|title=The lobopodian ''Paucipodia inermis'' from the Lower Cambrian Chengjiang fauna, Yunnan, China|url=https://www.academia.edu/4190258|journal=Lethaia|volume=37|issue=3|pages=235–244|doi=10.1080/00241160410006555|bibcode=2004Letha..37..235H }}</ref> The gut consists of a central tube occupying the full length of the lobopodian's trunk,<ref name="Liu2006">{{cite journal |title=A large xenusiid lobopod with complex appendages from the Lower Cambrian Chengjiang Lagerstätte|author1=Jianni Liu |author2=Degan Shu |author3=Jian Han |author4=Zhifei Zhang |author5=Xingliang Zhang  |name-list-style=amp |journal=Acta Palaeontol. Pol. |volume=51 |issue=2 |pages=215–222 |year=2006 |url=http://www.app.pan.pl/archive/published/app51/app51-215.pdf |archive-url=https://ghostarchive.org/archive/20221010/http://www.app.pan.pl/archive/published/app51/app51-215.pdf |archive-date=2022-10-10 |url-status=live |access-date=9 February 2011}}</ref> which does not change much in width - at least not systematically. However, in some groups, specifically the gilled lobopodians and siberiids, the gut is surrounded by pairs of serially repeated, kidney-shaped gut diverticulae (digestive glands).<ref name="Liu2006" /><ref name="Liu2007">{{cite journal| first1 = J. |first2=D. |first3=J. |first4=Z. | first5=X. |title=Morpho-anatomy of the lobopod Magadictyon cf. Haikouensis from the Early Cambrian Chengjiang Lagerstätte, South China |journal=Acta Zoologica |volume=88 |issue=4 |pages=279–288 |year=2007 |last1=Liu |doi=10.1111/j.1463-6395.2007.00281.x |last2=Shu |last3=Han |last4=Zhang |last5=Zhang}}</ref><ref name=":5" /> In some specimens, parts of the lobopodian gut can be preserved in three dimensions. This cannot result from phosphatisation, which is usually responsible for 3-D gut preservation,<ref name="LeancholiaGuts">{{cite journal |first1=N. J. |title=Leanchoilia guts and the interpretation of three-dimensional structures in Burgess Shale-type fossils |journal=Paleobiology |volume=28 |pages=155–171 |year=2002 |issn=0094-8373 |last1=Butterfield |issue=1 |doi=10.1666/0094-8373(2002)028<0155:LGATIO>2.0.CO;2 |bibcode=2002Pbio...28..155B |s2cid=85606166}}</ref> because the phosphate content of the guts is under 1%; the contents comprise quartz and muscovite.<ref name="Hou2004" /> The gut of the representative ''[[Paucipodia]]'' is variable in width, being widest at the centre of the body. Its position in the body cavity is only loosely fixed, so flexibility is possible.

[[File:20191029 Kerygmachela brain and digestive system.png|thumb|Eyes (deep blue), brain (light blue) and digestive system (yellow) of ''[[Kerygmachela]]''.]]

Not much is known about the neural anatomy of lobopodians due to the spare and mostly ambiguous fossil evidence. Possible traces of a nervous system were found in ''[[Paucipodia]]'', ''[[Megadictyon]]'' and ''[[Antennacanthopodia]]''.<ref name="Liu2007" /><ref name="Hou2004" /><ref name=":3" /> The first and so far the only confirmed evidence of lobopodian neural structures comes from the gilled lobopodian ''[[Kerygmachela]]'' in Park et al. 2018 — it presents a brain composed of only a protocerebrum (the frontal-most cerebral [[ganglion]] of [[panarthropods]]) that is directly connected to the nerves of eyes and frontal appendages, suggesting the protocerebral ancestry of the head of lobopodians as well as the whole [[Panarthropoda]].<ref name=":14" />

In some extant [[ecdysozoa]]n such as [[priapulid]]s and [[onychophora]]ns, there is a layer of outermost circular muscles and a layer of innermost longitudinal muscles. The onychophorans also have a third, intermediate, layer of interwoven oblique muscles. Musculature of the gilled lobopodian ''[[Pambdelurion]]'' shows a similar anatomy,<ref name=":29" /> but that of the lobopodian ''[[Tritonychus]]'' shows the opposite pattern: it is the outermost muscles that are longitudinal and the innermost layer that consists of circular muscles.<ref name=":34">{{Cite journal|last1=Zhang|first1=Xi-Guang|last2=Smith|first2=Martin R.|last3=Yang|first3=Jie|last4=Hou|first4=Jin-Bo|date=2016|title=Onychophoran-like musculature in a phosphatized Cambrian lobopodian|journal=Biology Letters|language=en|volume=12|issue=9|pages=20160492|doi=10.1098/rsbl.2016.0492|pmid=27677816|pmc=5046927|issn=1744-9561}}</ref>