Comment on "Ultrastructure reveals ancestral vertebrate pharyngeal skeleton in yunnanozoans"

Tian et al. (Research Articles, 8 July 2022, abm2708) hypothesized that yunnanozoans are stem-group vertebrates on the basis of "cellular cartilage", "fibrillin microfibers", and "subchordal rod" associated with the branchial arches of yunnanozoans. However, we reject the presence of cellular cartilage, fibrillin, and the phylogenetic proposal of vertebrate affinities based on ultrastructure and morphology of yunnanozoans from more than 8000 specimens.