It turns out that some seemingly silent animals are not so quiet after all. A new study from journal Nature Communications says that more than 53 species assumed non-verbal—including turtles, caecilian (limbless amphibians), tuataras (lizard-like reptiles), and South American lungfish—actually intentionally communicate through sound.

The acoustics, which take various forms (singing, croaks, snorts, and chirps among them) are not new—research found that they date to the Devonian period, 400 million years ago, and a single ancestor. The sounds simply went undetected due to human bias and the difficulty to hear and record sound underwater.

Study author Gabriel Jorgewich-Cohen, a PhD student at the University of Zurich, detailed some of the turtle’s communication styles to the BBC. According to Jorgewich-Cohen, turtles sing to announce their desire to mate, and even sing from within their eggs prior to hatching to ensure a safe and coordinated arrival into the world.

The study is a major step in understanding and broadening a comprehensive evolutionary tree. “Our results now show that acoustic communication did not evolve multiple times in diverse clades, but has a common and ancient evolutionary origin,” says study leader Marcelo Sánchez.

The takeaway? If we want to understand the true origin of all species, we better listen up!