Both modern crocodilians and birds, the closest living relatives of dinosaurs, have four-chambered hearts, although modified in crocodilians, and so dinosaurs probably had them as well.
I današnji krokodili i ptice, najbliži živući srodnici dinosaura, imaju četverodijelno srce, iako malo drugačije kod krokodila, i dinosauri su ga vjerojatno također imali.