A total of 17 new species were discovered in an underwater nursery that dates back about 518 million years. The nursery, which is located at a site close to Kunming, China, named the Haiyan Lagerstätte, contains one of the most diverse and oldest collections of Cambrian-era fossils ever discovered.
Researchers recovered over 2,800 fossils belonging to at least 118 different species that includes ancestors of today’s insects, jellyfish, worms, crustaceans, sponges, trilobites, algae, and vertebrates that are related to jawless fish. They were killed (and some may have went completely extinct) when a large amount of sediment avalanched down a hill and buried thousands of these creatures as well as their babies. It’s not entirely clear what caused the “avalanche” but it may have been due to a change in the level of oxygen or perhaps a strong storm that sent the sediment into the sea.
Incredibly, 17 of the species are completely new to science with 51% of the fossils belonging to juveniles and several of them being larval creatures that still had their soft tissue. Preserved eggs were even found at the site that researchers have described as being a “paleo nursery”.
In a statement, Julien Kimmig, who is a collections manager at the Earth and Mineral Sciences Museum & Art Gallery at Penn State University, described the significance of finding juvenile fossils, “It’s just amazing to see all these juveniles in the fossil record,” adding, “Juvenile fossils are something we hardly see, especially from soft-bodied invertebrates.”
The fossils were exceptionally well preserved that some of them still contained several body parts that have never been witnessed before. In the same statement, Sara Kimmig who is an assistant research professor in the Earth and Environmental Systems Institute and facility director of the Laboratory for Isotopes and Metals in the Environment at Penn State, said “The site preserved details like 3D eyes, features that have never really been seen before, especially in such early deposits.” The researchers were then able to create 3D models of the specimens by using CT scans. (Pictures of some of the fossils can be seen here.)
The study was published in the journal Nature Ecology and Evolution where it can be read in full.