A newly discovered fossil of an ancient shrimp-like arthropod discovered by scientists could take us way back in time.

The 520 million-year-old fossil – about three inches long – of an extinct marine creature called Fuxianhuia protensa – ancestral to modern day arthropods – is the earliest known cardiovascular system to have been discovered by scientists so far.

"This is the first preserved vascular system that we know of," Nicholas Strausfeld, a Regents' Professor of Neuroscience at the University of Arizona's Department of Neuroscience, who helped analyze the find said in a press release.

Found in sedimentary rocks of fine-grain mudstone from the lower Cambrian period in southwest China, such an elaborate and "remarkable example" of preservation is quite rare.

"Fuxianhuia is relatively abundant, but only extremely few specimens provide evidence of even a small part of an organ system, not even to speak of an entire organ system," said Dr. Strausfeld, an author on the paper published in Nature Communications.

At this point researchers don't know exactly why the fossil was preserved , but some speculations point toward some kind of a calamity that might have created conditions conducive to its preservation. For example, the habitats of these creatures might have been inundated due to ferocious sandstorms. "We believe that these animals were preserved because they were entombed quickly under very fine-grained deposits during some kind of catastrophic event, and were then permeated by certain chemicals in the water while they were squashed flat. It is an invertebrate version of Pompeii," Strausfeld said.

Another possibility is that tsunamis might have been responsible for preserving the deposits. "As the water withdraws, animals on the seafloor dry," Strausfeld said. "When the water rushed back in, they might become inundated with mud. Under normal circumstances, when animals die and are left to rot on the seafloor, they become unrecognizable. What happened to provide the kinds of fossils we are seeing must have been very different."

Using imaging techniques, researchers closely studied the preserved vascular system of the fossil. "With that, we can now start speculating about behavior," Strausfeld explained. "Because of well-supplied blood vessels to its brain, we can assume this was a very active animal capable of making many different behavioral choices."

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

The brain of the animal was highly vascularized which suggests it required a lot of oxygen. The eyes were on moveable stalks, indicating that the animal used active vision. It probably had a lot of lot of chemoreceptors on its antennae. It had swimming appendages. The findings indicate that the animal was probably a forager and had good olfactory perception, Strausfeld told the Monitor.

"Different groups of crustaceans have vascular systems that have evolved into a variety of arrangements but they all refer back to what we see in Fuxianhuia," he added.