In 2014 an international scientific team reported discovering an important fossil in China.
It wasn't a Tyranosaurus Rex tooth or a giant bone from a supersaurus. It was the skeleton of an oval, bag‑like animal about four inches tall, covered with dagger‑like spines, that paleontologists named Nidelric pugio.
It made big news because the fossil was inside a 520 million year old rock from the Cambrian geological period. That's more than 300 million years older than the dinosaurs! Most of the earliest evidence of animal life comes from the Cambrian, and modern animal groups were just getting started.
Sponge-like and Spiny
Nidelric was probably like a sponge in some ways, like being anchored to the seabed, and filtering water for food. Its spines protected it from being eaten. But, based on the structure of the spines, the paleontologists that found it think it probably wasn't a sponge.
It may be one of the few intact specimens of a very mysterious group of animals called the chancelloriids. This group had mostly been known from broken-up pieces and spines. Because its spines were simpler than other chancelloriids, Nidelric might have been their ancestor.
Some groups of prehistoric animals have modern descendants. The birds are the modern descendants of dinosaurs. Other animal groups, especially from way back in the Cambrian, just vanished. Nidelric is important because it may give us a glimpse into that lost world.
"Fossils Across Geological Time and Evolution" (The Virtual Fossil Museum)
"Ancient Balloon‑Shaped Animal Fossil Sheds Light On Earth's Ancient Seas" (University of Leicester)