Cardiodictyon is a genus of lobopodian known from 518 millions years old Chengjiang Lagerstätte. 525 millions years old partial fossil is also reported.
Discovery and naming
Description
It has ~25 pairs of legs, each associated with a pair of dorsal plates. Each leg terminates in a pair of claws.Ramsköld, L., & Chen, J.-Y. (1998). Cambrian Lobopodians: Morphology and Phylogeny. In Arthropod fossils and phylogeny (pp. 107–150). New York: Columbia University Press. 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.
References