Articulated Xiushanosteus from the Chongqing Lagerstätte
Holotype IVPP V300001 and twenty referred specimens preserve an approximately 30 mm, near-complete placoderm-grade stem gnathostome at about 436 Ma, directly exposing a mosaic skull roof and body plan without identifying an ancestor of crown jawed vertebrates.
Represented range436–436 Ma
RegionsHuixingshao Formation, Yongdong, Xiushan, Chongqing, China
Xiushanosteus mirabilis holotype IVPP V300001 and referred specimens IVPP V300002–V300021 from the middle-to-late Telychian Huixingshao Formation at approximately 436 Ma preserve an approximately 30 mm placoderm-grade stem-gnathostome body and a mosaic skull roof; this is articulated specimen evidence, not a direct ancestor, global dominance estimate or global jawed-vertebrate FAD.