Rangeomorphs, Thectardis (Porifera?) and dissolved organic carbon in the Ediacaran oceans

A groundbreaking analysis of the Mistaken Point biota, a mid-Ediacaran fossil assemblage in Newfoundland, suggests that the enigmatic fossil Thectardis avalonensis is likely a sponge. This interpretation, supported by its body plan and hydrodynamics, provides some of the earliest macroscopic evidence for sponges, a group previously known only through biomarkers and molecular clocks. The study further implies that the Mistaken Point ecosystem was dominated by sponges and rangeomorphs, organisms hypothesized to feed on dissolved organic carbon (DOC). This challenges traditional views of Ediacaran ocean dynamics, proposing that labile DOC was delivered non-uniformly to the seafloor, reshaping our understanding of early marine ecosystems.

SPERLING, E. A., PETERSON, K. J., & LAFLAMME, M. (2010). Rangeomorphs, Thectardis (Porifera?) and dissolved organic carbon in the Ediacaran oceans. Geobiology, 9(1), 24–33. https://doi.org/10.1111/j.1472-4669.2010.00259.x