Herpetogaster from the early Cambrian of Nevada (Series 2, Stage 4) and its implications for the evolution of deuterostomes

摘要

The Pioche Formation of SE Nevada preserves a diverse soft-bodied fauna from the early and middle Cambrian (Series 2-3: Stage 4-5). While the fauna is dominated by arthropods, animals belonging to other taxa can be found. Here we document the first occurrence of Herpetogaster collinsi outside the Burgess Shale. Further, the specimens are from the Nephrolenellus multinodus biozone and thus represent the oldest occurrence of the species, as well as possibly the earliest soft-bodied deuterostomes in Laurentia.