Biology:Cardiodictyon

Cardiodictyon is a genus of lobopodian known from 518 millions years old Chengjiang Lagerstätte. 525 millions years old partial fossil is also reported.

Description

It has ~25 pairs of legs, each associated with a pair of dorsal plates. Each leg terminates in a pair of claws. It may or may not have a head shield, though it certainly has an expanded head.

In 2022, a 518,000,000 years old specimen of C. catenulum was researched and shown an unsegmented head and a brain composed of three separate cephalic parts. However, although "three parts" in this study means prosocerebrum, protocerebrum and deutocerebrum, it is different from earlier studies that referred protocerebrum, deutocerebrum and tritocerebrum as tripartite brain of arthropod, and treated prosocerebrum as part of protocerebrum.

Classification

The slightly simplified cladogram below is from a paper by Knecht et al. redescribing the lobopodian Palaeocampa anthrax.

†Diania 80px       †Lenisambulatrix 80px         †Paucipodia 80px       †Thanahita 80px     †Eoconchariidae   †Microdictyon 80px     †Fusuchoncharium     †Quadratapora           †Xenusion 70px     †Onychodictyon 80px         †Strictocorniculum     †Rhombocorniculum     †Orstenotubulus90px     †Carbotubulus     †Hallucigenia fortis     †Hallucigenia sparsa 60px       †"Hallucigenia" hongmeia       †Cardiodictyon 80px       Tardigrada (tardigrades) 60px   †Luolishaniida     †Ovatiovermis 60px     †Facivermis 70px         †Luolishania 80px   †Collinsovermidae   †EBS Collinsovermid (SAM P14848)       †Acinocricus       †Collinsovermis 80px       †Collinsium 90px     †Entothyreos 60px                                 †Aysheaiidae   †Aysheaia 80px       Soom Shale lobopodian (C1947)       †Hadranax 80px     †Palaeocampa 80px         Antennopoda     †Antennacanthopodia 80px   Onychophora   †Antennipatus     †Cretoperipatus 80px     †Helenodora 90px     Living onychophorans 80px   (velvet worms)     †Siberiidae   †Siberion 80px     †Megadictyon 80px     †Jianshanopodia 80px           †Pambdelurion 80px     †Kerygmachelidae 80px         †Opabiniidae 80px       †Radiodonta (e.g. Anomalocaris) 80px     Deuteropoda (modern arthropods) 70px

References

Template:Lobopodia Wikidata ☰ Q16852076 entry