A team of paleontologists from the University of California, Riverside and the South Australian Museum has discovered the fossils of two soft-bodied animals that lived in the shallow oceans about 550 million years ago (Ediacaran period).
Named Obamus coronatus and Attenborites janeae, the newly-discovered fossil animals were part of the Ediacara biota.
“Obamus coronatus, a name that honors President Barack Obama’s passion for science, was between 0.5-2 cm across with raised spiral grooves on its surface,” explained Professor Mary Droser, from the University of California, Riverside, and co-authors.
“This disc-shaped creature did not seem to move around, rather it was embedded to the ocean mat, a thick layer of organic matter that covered the early ocean floor.”
“Attenborites janeae, named after the English naturalist and broadcaster Sir David Attenborough for his science advocacy and support of paleontology, was less than a centimeter across.”
“This tiny ovoid was adorned with internal grooves and ridges giving it a raisin-like appearance.”
In the hierarchical taxonomic classification system, the Ediacara biota are not yet organized into families, and little is known about how they relate to modern animals.
About 50 genera have been described, which often have only one species.
“The two genera that we identified are a new body plan, unlike anything else that has been described,” Professor Droser said.
“We have been seeing evidence for these animals for quite a long time, but it took us a while to verify that they are animals within their own rights and not part of another animal.”
The discovery is reported in two papers published in the Australian Journal of Earth Sciences, an international geoscience journal of the Geological Society of Australia.
P.W. Dzaugis et al. Stuck in the mat: Obamus coronatus, a new benthic organism from the Ediacara Member, Rawnsley Quartzite, South Australia. Australian Journal of Earth Sciences, published online June 14, 2018; doi: 10.1080/08120099.2018.1479306
S.D. Evans et al. You can get anything you want from Alice’s Restaurant Bed: exceptional preservation and an unusual fossil assemblage from a newly excavated bed (Ediacara Member, Nilpena, South Australia). Australian Journal of Earth Sciences, published online May 23, 2018; doi: 10.1080/08120099.2018.1470110