Study: Did Sharks Cannibalize Their Young? Teeth in Poop Fossil Say Yes

Scientists have discovered something strange in the behavior of ancient sharks. They have unearthed a fossilized poop of sharks, revealing that these animals cannibalize their babies.

According to the study published in the journal Paleontology, the spiral-shaped coprolite or fossilized poop of the ancient shark is dated 300 million years ago, when the animals rule "coal forests."

These so-called "coal forests" are steamy jungles that once wrapped Europe and North America when they lay the equator in the past.

The fossilized poop, according to Science Daily, is believed to have come from the shark species Orthacanthus, which midly resembles modern-day bull sharks. Upon close examination of the poop, what scientists discovered dumbfounded them -- it was full of teeth from young Orthacanthus, which proves that these sharks practice "fillial cannibalism."

"There is already evidence from fossilised stomach contents that ancient sharks like Orthacanthus preyed on amphibians and other fish, but this is the first evidence that these sharks also ate the young of their own species," Aodhán ó Gogáin, a PhD candidate who made the discovery, said via a press release from EurekAlert.

Howard Falcon-Lang, co-author of the study explains that they still do not know why these sharks eat their babies, but notes that the Carboniferous Period (the time where the Orthacanthus thrived), was a time where colonization of freshwater swamps were prevalent.

"It's possible that Orthacanthus used inland waterways as protected nurseries to rear its babies, but then consumed them as food when other resources became scarce."

Meanwhile, Gogáin describes the Orthacanthus sharks as xenacath sharks that grow up to three meters. It has an eel-like body, dorsal spine and tricusped teeth.

He added that these species are slightly like bull sharks today because it has the ability for ecological adaptation, migrating from coastal swamps to shallow seas.