The Cambrian Period lasted from543 million to 493 million years ago. Early life was much simpler from a bio-structural point of view, although Cambrian sea predator featured quite a simplistic brain. Anomalocaridids, or ‘abnormal shrimp’, was a Cambrian predatory group first discovered in the 19th century. Only in the 1980s the scientists managed to properly identify the species, but there are several schools of thought on where the primitive animal should be placed on the evolutionary scale.
New technology allows proper reanalysis of fossils discovered decades ago. By using computer simulations based on fossils discovered 30 years ago, another team of researchers identified what is believed to be the largest flying bird to have ever flown on Earth.
The Cambrian sea predator shares similarities with today’s velvet worm
Scientists from University of Arizona had the luck to analyze an extremely well preserved fossil from the Cambrian period. The discovery was made in Yunnan, a site in the south-west area of China. Brain tissues and the nervous system can clearly be seen, an outstanding characteristic for such an old fossil. The fossil has been categorized as being a part of a new species of anomalocaridids named Lyrarapax unguispinus. The animal was 5 inches long. The brain was positioned in front of its mouth and two groups of nerve cells were found between the claws and eyes. The animal’s structure is considered simple. But what amazes the scientists is that this animal is considered to be less smart than the animals it was feeding on. The sea predator Lyrarapax unguispinus has a structure similar to the velvet worm which lives today and are predators as well. In the Cambrian period, the majority of organic life lived in the water, while the land only supported simple microbial organisms.
“It turns out the top predator of the Cambrian had a brain that was much less complex than that of some of its possible prey and that looked surprisingly similar to a modern group of rather modest worm-like animals,” said Nicholas Strausfeld, director of the Univ. of Arizona’s Center for Insect Science.
The well preserved fossilized brain of the Cambrian sea predator allows research which can foster the development of a new field called neuropaleontology, Xiaoya Ma of the Natural History Museum in London added.
The details of the discovery are available in the article “Brain structure resolves the segmental affinity of anomalocaridid appendages,” published in the journal Nature.