Organically-preserved multicellular eukaryote from the early Ediacaran Nyborg Formation, Arctic Norway.

Eukaryotic multicellularity originated in the Mesoproterozoic Era and evolved multiple times since, yet early multicellular fossils are scarce until the terminal Neoproterozoic and often restricted to cases of exceptional preservation. Here we describe unusual organically-preserved fossils from mudrocks, that provide support for the presence of organisms with differentiated cells (potentially an epithelial layer) in the late Neoproterozoic. Cyathinema digermulense gen.

Cryogenian evolution of stigmasteroid biosynthesis.

Sedimentary hydrocarbon remnants of eukaryotic C-C sterols can be used to reconstruct early algal evolution. Enhanced C sterol abundances provide algal cell membranes a density advantage in large temperature fluctuations. Here, we combined a literature review with new analyses to generate a comprehensive inventory of unambiguously syngenetic steranes in Neoproterozoic rocks.