New research examining the jaws of over 90 shark species has highlighted how they changed over the course of evolution and how habitat has changed the shape of the jaws of different species.
The international team of researchers looked at the shape of the lower jaw in sharks and how this evolution allowed sharks to feed on a wide variety of prey. This in turn meant they could spread across the world’s oceans.
The team of scientists used X-ray computed tomographic scans to compare and study the relationship between the animals’ lifestyle and jaw morphology. In total, the team studies 90 species to reach the conclusion that the most widespread species have seen little change in the shape of their lower jaws over millions of years.
According to Faviel López-Romero, the lead scientist from the University of Vienna:
“Although sharks from the deep sea are not as extensively represented in the data as reef sharks, they display the most disparate forms seen in our analysis…Remarkable changes occurred in carpet, sleeper, and dogfish sharks. These changes were probably concomitant with the clear distribution of these sharks in reefs and the deep sea, which noticeably distinguishes them morphologically from other species with larger jaws as seen in the top predators in the open sea.”
While Jürgen Kriwet, another study participant also from the University of Vienna, added:
“Of course, many sharks in these environments feed on a large variety of prey with only few having adapted to a single, specific prey, such as the bonnethead shark, Sphyrna tiburo, which preys almost entirely on hard-shelled crabs, while shrimps and fish are only capture occasionally.”
You can find the original research here.
