It is well known that our early years can go on to shape much of our adult lives, for better or worse. Many of us, who are fortunate enough, spend them sipping juice boxes and jumping rope with our friends, perhaps reciting nursery rhymes or learning our ABCs. Not so many of us spend them chilling in the ocean, before being buried in an avalanche of sediment. This was the case for thousands of young vertebrates and other rare, soft-bodied organisms being cared for in a paleonursery some 500 million years ago. Childcare has certainly changed a little in the last half an eon.
Now, researchers have discovered evidence of these poor young things and the devastating event that wiped them out. More than 2,800 fossils – 51 percent of which are larvae, juveniles, or subadults – have been unearthed near Kunming, China. The site, named the Haiyan Lagerstätte, is home to a Cambrian-era graveyard, which contains the oldest and most diverse fossil troves found to date. Their findings are published in the journal Nature Ecology and Evolution. Among the fossils are 118 species – 17 of which are brand new – including ancestors of modern-day insects, crustaceans, worms, trilobites, algae, and sponges.
The fossils date back to the Cambrian period – 540 to 490 million years ago – an era defined by an explosion of biodiversity and rise in complex multicellular life forms which has underpinned all modern animal groups. The earliest evidence of parenting was also discovered in this period. The Haiyan Lagerstätte may have attracted these parents as a good place to raise their young – the study authors suggest that the site may have offered protection against predation, as well as abundant food sources, prompting them to establish a paleonursery. Apparently, Cambrian parents were the nurturing kind.
“It’s just amazing to see all these juveniles in the fossil record,” said Julien Kimmig, collections manager at the Earth and Mineral Sciences Museum & Art Gallery, Penn State, in a statement. “Juvenile fossils are something we hardly see, especially from soft-bodied invertebrates.”
The fossils are also remarkably well preserved: “the site preserved details like 3D eyes, features that have never really been seen before, especially in such early deposits,” said Sara Kimmig, 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.
The findings, therefore, will shed light on the anatomy and development of these ancient animals. They may even further our understanding as to how these organisms laid the foundations for life today.
"We'll see how different body parts grew over time, which is something we currently do not know for most of these groups," Julien Kimmig said. "And these fossils will give us more information on their relationships to modern animals. We will see if how these animals develop today is similar to how they developed 500 million years ago, or if something has changed throughout time." Studying this developmental information may also clarify relationships between species, as similar development patterns may indicate a link, he added.
"The Haiyan Lagerstätte will be a wealth of knowledge moving forward for many researchers, not only in terms of paleontology but also in paleo-environmental reconstructions," said Sara Kimmig.
Who knew a nursery could teach us so much?