2016/03/01 by Jie Yang, Javier Ortega‐Hernández, Nicholas J. Butterfield +5 · 2 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Tardigrade Biology and Ecology #Cephalopods and Marine Biology #Protist diversity and phylogeny
paper · pdf · doi:10.1073/pnas.1522434113
openalex publication_date 2016/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Panarthropods are typified by disparate grades of neurological organization reflecting a complex evolutionary history. The fossil record offers a unique opportunity to reconstruct early character evolution of the nervous system via exceptional preservation in extinct representatives. Here we describe the neurological architecture of the ventral nerve cord (VNC) in the upper-stem group euarthropod Chengjiangocaris kunmingensis from the early Cambrian Xiaoshiba Lagerstätte (South China). The VNC of C. kunmingensis comprises a homonymous series of condensed ganglia that extend throughout the body, each associated with a pair of biramous limbs. Submillimetric preservation reveals numerous segmental and intersegmental nerve roots emerging from both sides of the VNC, which correspond topologically to the peripheral nerves of extant Priapulida and Onychophora. The fuxianhuiid VNC indicates that ancestral neurological features of Ecdysozoa persisted into derived members of stem-group Euarthropoda but were later lost in crown-group representatives. These findings illuminate the VNC ground pattern in Panarthropoda and suggest the independent secondary loss of cycloneuralian-like neurological characters in Tardigrada and Euarthropoda.