Dumbbell-shaped gogiid clusters: the oldest evidence of secondary tiering for stalked echinoderms



Jih-Pai Lin [jih-pai.lin@yale.edu], Department of Geology and Geophysics, 210 Whitney Avenue, Yale University, New Haven, CT 06511, USA


Among 381 specimens of Cambrian stalked echinoderms from eastern Guizhou, China examined, several slabs (n = 19) contain either dumbbell-shaped or v-shaped echinoderm clusters. Four slabs of Globoeocrinus globules Zhao, Parsley & Peng, 2008 from the middle-upper part (Cambrian Series 3 portion) of the Kaili Formation are prepared to reveal the attachment sites. Articulated gogiid echinoderms are reported to be attached to both sides of inarticulate (organophosphatic) brachiopods; thus, allowing me to interpret that the larvae of these gogiids were capable of attaching to live benthic brachiopods. This study documents the one of the earliest examples of echinoderms employing secondary tiering, which elevates an organism higher into the benthic boundary layer. Many of the gogiid echinoderm pairs attached to a live brachiopod are similar in size, indicating they were from a single larval spatfall.