Researchers have identified the heart and blood vessels of early Cambrian shrimp-like creatures from southwest China. The 520-million-year-old fossilized remains of the Chengjiang arthropod Fuxianhuia protensa reveal an exceptionally well-preserved organ system that’s surprisingly sophisticated. For something with such a simple body plan, its complexity rivals the vascular system of today’s arthropods, such as scorpions and horseshoe crabs.

read more: 520 Million Year Old Cardiovascular System Found | I Fucking Love Science.