Skeletons evolved as ocean chemistry changed
Skeletons and shells first came into being 550 million years ago as the chemical make-up of seawater changed, a study suggests.
|Fieldwork at the Yudoma River in Siberia, Russia |
[Credit: Rachel Wood]
Until now, little was known about how skeletons and shells – which are made of calcium carbonate – first evolved, the team says. Previous theories suggested that soft-bodied organisms had undergone a mass extinction, which allowed organisms with skeletons and shells to flourish.
However, Edinburgh researchers have found that the earliest lifeforms with hard body parts co-existed with closely related soft-bodied species. The team examined a range of fossils unearthed from limestone rocks in Siberia, which formed millions of years ago from seawater with high levels of calcium carbonate.
|Artist's impression of a Suvorevella fossil, one of the oldest known skeletal macrofossils |
[Credit: Alina Konovalenko]
The development of hard body parts – through a process called biomineralisation – marked a significant evolutionary advance from the previous world of soft-bodied life, the team says. The study is published in the journal Proceedings of the Royal Society B. The research was carried out in collaboration with Lomonosov Moscow State University.
"How animals produced shells and skeletons is one of the major events in the evolution of life. We are only now starting to understand the processes underlying this revolution," says Professor Rachel Wood of the School of GeoSciences.
Source: University of Edinburgh [April 04, 2017]