Odd new shark species with humanlike molars discovered in Australia
Scientists from Australia found a novel kind of shark that has unusual, human-like molars that can be used to crush on its prey.
The new, dubbed painted horn shark ( Heterodontus marshallae) is part of the order Heterodontiformes that are distinguished due to their unique body form and the small horns extending from their eyes.
“This order of sharks resembles fossils of long extinct sharks due to similar morphology, including spines. But we know now they’re not closely related,” Helen O’Neill, an expert in fish biology in the Australian National Fish Collection (ANFC), part of the Australian government agency CSIRO, said in an announcement.
The new species has been described as only located in the waterways of the northwest region of Australia, around 700 to 410 feet (125 to 229 meters) below the surface, as per an article published on July 12 in the Journal of Diverse.
They have numerous rows of teeth and a vast jaw compared to their skulls, allowing them to eat mollusks and crustaceans.
“The teeth of all of the hornshark species are very similar to each other, but hornsharks as a group have very different teeth to most other sharks. [They] have grasping teeth near front and large molar-like teeth as you move back along the jaw,” Will White, a senior curator at the ANFC and co-author of the study, said to Live Science in an email. “This group has evolved to crush heavy shelled prey utilising its molar-like teeth.”
In November 2022 sci,entists were studying the seabed habitat in the Gascoyne Marine Park in Western Australia when they spotted one adult male H. marshallae, which was 1.75 inches (53 centimeters) in length when measured from the point of its snout down to the tail end of its fin.
“Compared to other Australian hornsharks, this species has a distinctive striped pattern,” White explained. “This pattern is very similar to the Zebra hornshark and was previously thought to be the same species.”
However, zebra horn sharks (H. zebra) can be found in shallower waters and typically live close to Indonesia or Japan and H. marshallae. H. marshallae prefers the more bottomless ocean that surrounds Australia’s coast. BeforeBefore the 2022 voyage, researchers had examined six specimens and an egg casing that was later classified as H. marshallae from museum collections throughout Australia and were working on the classification of the brand new species when they came on the male living.
“We have a female specimen in our collection, but the one we collected during the voyage is a male,” O’Neill, co-author of the study, wrote in the announcement. “We prefer to use males for shark holotypes because they have claspers, which are external reproductive organs that can vary between species and help us tell them apart.”
Researchers last identified the shark as a species belonging to the class Heterodontiformes in 2005. White said that scientists are unsure if they’ll find another of these sharks that hunt underwater.
“This order of sharks and very distinctive in their large head, crests above eyes and spines in front of dorsal fins,” the expert stated. “My gut feeling is that we would have seen specimens of such a distinct species since they are mostly shallow water… where exploration has been substantial in most places. I could just as easily be wrong though.”