Universidad Complutense de Madrid researchers found mineralised fossil of 530 million years old sponges in the world in Ciudad Real. Spicules were also found among the fossil remains. Spicules is units of silicon that make skeleton from two types of sponges named hexactinillida and demosponges.
The sponges can have mineralised or non-mineralised skeletons. Researchers found 890 million years old fossil. This fossil is thought to be a remain of non-mineralised sponges.
Sponges are considered to be the first animals to evolve. So, this discovery will reveal new information about the evolution of living beings.
The researchers have gone on a fieldwork in 2019 and collected more than 200 samples from Ciudad Real. They examined the samples by microscopic and chemical analysis.
The researchers also discovered that the samples belonged to the early Cambrian period.
These sponges that are found lived on marine platform with microbes and other organisms. So, tides and storms washed away their remains to deeper waters. The remains were buried there under other layers of sediment. Millions of years later, the Variscan orogeny formed mountains and the fossils were displayed on the surface of Iberian Peninsula.