An article published in the journal “Science Advances” reports an analysis of fossils of Namacalathus hermanastes, an organism that lived in the Ediacaran period. A team of researchers subjected exceptionally preserved fossils dating back approximately 547 million years to a sophisticated X-ray tomographic examination. This also allowed fossilized soft tissue to be found for the first time in this species. The details of the two specimens examined led to the discovery of the link between animals that lived in the so-called Cambrian explosion and one of their ancestors.
Namacalathus hermanastes is an animal first discovered in the Nama Group, Namibia, and described in 2000. Currently, that’s the Namib desert but there’s the oldest coral reef ever discovered. It was produced about 547 million years ago by the first animals with skeletons. To be precise, they had an exoskeleton, possibly developed following the emergence of the first predators. Namacalathus hermanastes was one of the organisms of the so-called Ediacara biota, which had forms that were very different from the later ones with the consequent difficulty in placing them in the phyla that emerged in the Cambrian period. A team of researchers might have found a link between Namacalathus hermanastes and Cambrian animals.
For years, Namacalathus hermanastes fossils discovered included only their skeleton, but some specimens discovered by Professor Rachel Wood of the Scottish University of Edinburgh and her colleagues were found to be particularly well preserved. As a result, they were subjected to an X-ray tomographic examination that allowed them to study their details, including the soft tissues that in this case fossilized along with the skeleton. Other examinations were conducted with the electron microscope. The image (Courtesy Shore et al.) Shows various views of Namacalathus hermanastes fossils.
The 3D reconstruction of the Namacalathus hermanastes specimens carried out thanks to the tomographic examination allowed to compare their characteristics with those of known phyla. The researchers concluded that this primitive animal up to 3 centimeters long is an ancestor of groups that emerged a few million years later, in the Cambrian explosion, the largest diversification event in the history of life on Earth. The groups that may have descended from Namacalathus hermanastes are the Lophophorata, which include the phylums Brachiopoda, Phoronida, and Bryozoa.
The discovery of very well preserved fossils that also include soft tissues and the application of modern technologies to examine them made it possible to find similarities between one of the mysterious organisms of the Ediacaran period and the later ones, which are known much better. This doesn’t necessarily mean the end of the discussions on Namacalathus hermanastes, but now they have much more data to comment on.
