The dawn of animals remains one of the most mysterious milestones in the evolution of life. The fossil lipids 24-isopropylcholestane and 26-methylstigmastane are considered diagnostic for demosponges—arguably the oldest group of living animals. The widespread occurrence and high relative abundance of these biomarkers in Ediacaran sediments from 635–541 million years (Myr) ago have been viewed as evidence for the rise of animals to ecological importance approximately 100 Myr before their rapid Cambrian radiation. Here we show that the biosynthesis of 24-isopropylcholestane and 26-methylstigmastane precursors is common among early-branching unicellular Rhizaria—heterotrophic protists that play an important role in trophic cycling and carbon export in the modern ocean. Negating these hydrocarbons as sponge biomarkers, our study places the oldest evidence for animals closer to the Cambrian Explosion. Cambrian silica hexactine spicules that are approximately 535 Myr old now represent the oldest diagnostic sponge remains, whereas approximately 558-Myr-old Dickinsonia and Kimberella (Ediacara biota) provide the most reliable evidence for the emergence of animals. The proliferation of predatory protists may have been responsible for much of the ecological changes during the late Neoproterozoic, including the rise of algae, the establishment of complex trophic relationships and the oxygenation of shallow-water habitats required for the subsequent ascent of macroscopic animals.
Nettersheim B.J., Brocks J.J., Schwelm A., Hope J.M., Not F., Lomas M., Schmidt C., Schiebel R., Nowack E.C.M., De Deckker P., Pawlowski J., Bowser S.S., Bobrovskiy I., Zonneveld K., Kucera M., Stuhr M. and Hallmann C. (2019) Putative sponge biomarkers in unicellular Rhizaria question an early rise of animals. Nature Ecology & Evolution 3: 577-581. 10.1038/s41559-019-0806-5
@article{Nettersheim2019,
Title = {Putative sponge biomarkers in unicellular Rhizaria question an early rise of animals},
Author = {Nettersheim, Benjamin J. and Brocks, Jochen J. and Schwelm, Arne and Hope, Janet M. and Not, Fabrice and Lomas, Michael and Schmidt, Christiane and Schiebel, Ralf and Nowack, Eva C. M. and De Deckker, Patrick and Pawlowski, Jan and Bowser, Samuel S. and Bobrovskiy, Ilya and Zonneveld, Karin and Kucera, Michal and Stuhr, Marleen and Hallmann, Christian},
Editor = {},
Journal = {Nature Ecology & Evolution},
Year = {2019},
Pages = {577-581},
Volume = {3},
Doi = {10.1038/s41559-019-0806-5},
Abstract = {The dawn of animals remains one of the most mysterious milestones in the evolution of life. The fossil lipids 24-isopropylcholestane and 26-methylstigmastane are considered diagnostic for demosponges—arguably the oldest group of living animals. The widespread occurrence and high relative abundance of these biomarkers in Ediacaran sediments from 635–541 million years (Myr) ago have been viewed as evidence for the rise of animals to ecological importance approximately 100 Myr before their rapid Cambrian radiation. Here we show that the biosynthesis of 24-isopropylcholestane and 26-methylstigmastane precursors is common among early-branching unicellular Rhizaria—heterotrophic protists that play an important role in trophic cycling and carbon export in the modern ocean. Negating these hydrocarbons as sponge biomarkers, our study places the oldest evidence for animals closer to the Cambrian Explosion. Cambrian silica hexactine spicules that are approximately 535 Myr old now represent the oldest diagnostic sponge remains, whereas approximately 558-Myr-old Dickinsonia and Kimberella (Ediacara biota) provide the most reliable evidence for the emergence of animals. The proliferation of predatory protists may have been responsible for much of the ecological changes during the late Neoproterozoic, including the rise of algae, the establishment of complex trophic relationships and the oxygenation of shallow-water habitats required for the subsequent ascent of macroscopic animals.},
}
TY - JOUR
AU - Nettersheim, Benjamin J.
AU - Brocks, Jochen J.
AU - Schwelm, Arne
AU - Hope, Janet M.
AU - Not, Fabrice
AU - Lomas, Michael
AU - Schmidt, Christiane
AU - Schiebel, Ralf
AU - Nowack, Eva C. M.
AU - De Deckker, Patrick
AU - Pawlowski, Jan
AU - Bowser, Samuel S.
AU - Bobrovskiy, Ilya
AU - Zonneveld, Karin
AU - Kucera, Michal
AU - Stuhr, Marleen
AU - Hallmann, Christian
TI - Putative sponge biomarkers in unicellular Rhizaria question an early rise of animals
T2 - Nature Ecology & Evolution
PY - 2019
SP - 577-581
VL - 3
DO - 10.1038/s41559-019-0806-5
AB - The dawn of animals remains one of the most mysterious milestones in the evolution of life. The fossil lipids 24-isopropylcholestane and 26-methylstigmastane are considered diagnostic for demosponges—arguably the oldest group of living animals. The widespread occurrence and high relative abundance of these biomarkers in Ediacaran sediments from 635–541 million years (Myr) ago have been viewed as evidence for the rise of animals to ecological importance approximately 100 Myr before their rapid Cambrian radiation. Here we show that the biosynthesis of 24-isopropylcholestane and 26-methylstigmastane precursors is common among early-branching unicellular Rhizaria—heterotrophic protists that play an important role in trophic cycling and carbon export in the modern ocean. Negating these hydrocarbons as sponge biomarkers, our study places the oldest evidence for animals closer to the Cambrian Explosion. Cambrian silica hexactine spicules that are approximately 535 Myr old now represent the oldest diagnostic sponge remains, whereas approximately 558-Myr-old Dickinsonia and Kimberella (Ediacara biota) provide the most reliable evidence for the emergence of animals. The proliferation of predatory protists may have been responsible for much of the ecological changes during the late Neoproterozoic, including the rise of algae, the establishment of complex trophic relationships and the oxygenation of shallow-water habitats required for the subsequent ascent of macroscopic animals.
ER -
