Coral reefs offer a habitat for a variety of species. A similar function already fulfilled reef -forming sponges in the Paleozoic. In fossil reefs in southern China, researchers have now discovered a sponge that built a stable skeleton 480 million years ago – 20 million years earlier than before. It is also unusual that the sponge, to which the researchers gave the Lophiostroma Leizunia, set up his skeleton from the Mineral Fluorapatite, a material that has so far not been observed in any other sponge. The findings provide new insights into the emergence of the earliest reefs.
Riffoning organisms such as corals create unique ecosystems under water that offer a habitat for numerous animals and plants. The basic structure of the reefs form the skeletons of corals and Co. These usually consist of calcium carbonate and remain even after the death of the individual. Already in the Paläozoikum, long before the first coral reefs emerged, reef -forming sponges, the so -called stromatopores, spread in different parts of the world. So far, little was known about their beginnings.
Fluorapatite skeleton
In fossil reefs in southern China, a team led by Juwan Jeon from Korea University in South Korean Seoul has now discovered the oldest known kind of a reef -forming sponge. The species, which gave the researchers the name Lophiostroma Leizunia, formed reefs 480 million years ago. “This discovery shifts the fossil evidence of reef -forming stromatopores by about 20 million years and reveals its crucial role in reef construction,” reports the team. “This revolutionizes our understanding of the early reef ecosystems and biomineralization.”
The researchers collected a total of 420 kilograms of fossil samples and analyzed them both with the electron microscope and with various chemical processes. According to this, the newly discovered species formed its skeleton from an extraordinary material for sponges: “The skeleton of L. Leizunia unusually consisted of the Mineral Fluorapatite,” the researchers report. It is a connection from fluorine and calcium phosphate. Previously known types of sponges, on the other hand, use either calcium carbonate, i.e. lime, or silica, consisting of silicon. “This makes sponges the first animal strain that is known that it uses all three important biominerals: silica, calcium carbonate and calcium phosphate,” said the team.
Lamellae and columns
Comparisons with relatives living today suggest that the upper part of the body of L. Leizunia consisted of soft tissue. The skeleton, on the other hand, was made up of several delicate, slat -like layers. In addition, the sponge formed fine, column -shaped structures, which, from the point of view of the researchers, was probably produced by specialized cells. “This complex column structure indicates a high degree of control over biomineralization,” explains the team. “L. Leizunia is unique among the well -known sponges, not only through the use of fluorapatite as a biomineral, but also through the elegantly controlled structure of his skeleton.”
The fossil rehearsal samples also revealed that the scaffolds created by the sponge also housed other organisms, including lime microbes, other sponges, plants and stinghes. “This offers new insights into the evolutionary dynamics of biomineralization and the emergence of reef ecosystems,” explain Jeon and his colleagues. “This fossil is proof that sponges have researched more physiological possibilities than previously known.”
Source: Juwan Jeon (Korea University, Seoul, Republic of Korea) et al., Proceedings of the National Academy of Sciences, DOI: 10.1073/PNAS.2426105122