Scientists have reportedly discovered the earliest known example of an advanced cardiovascular system, according to a study published in Nature Communications.

The heart and blood vessels were discovered inside the body of a 520-million-year old shrimp-like species.

"This is the first preserved vascular system that we know of," said Nicholas Strausfeld, a neuroscience professor at the University of Arizona's Department of Neuroscience, who helped with the study.

The shrimp, which was a part of the now-extinct arthropod species known as Fuxianhuia protensa, was discovered among rich fossil deposits in the Yunnan province of China.

In the fossil deposits, "thousands" of creatures from the Cambrian Period were entombed by dust particles. The Cambrian Period was around 520 million years ago, and the creatures were likely entombed by some sort of catastrophic event, according to the study.

Entombed animals were preserved in mudstone, and Strausfeld confirmed that the vascular system found in the ancient shrimp is "more advanced" than the cardiovascular organs of most modern crustaceans.

"It appears to be the ground pattern from which others have evolved," Strausfeld said. "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.

Scientists from the University of Arizona, China and the U.K. helped with the study.

Research was published in a recent edition of the journal Nature Communications.