Paleontologists have discovered seven well-preserved shark teeth of the extinct genus Petalodus in China's Shanxi province. An article about this was published in the journal Acta Geologica Sinica.
The genus Petalodus, first described in 1840, belonged to the order Petalodontiformes - petalodonts, fossil marine cartilaginous fish that lived in the ancient seas from the Carboniferous to the Permian period. It is related to the modern order of chimera-like, but the overwhelming majority of the species that represented that order had already disappeared by the end of the mass Permian extinction 250 million years ago.
The newly discovered teeth belong to the species Petalodus ohioenesis, which lived about 290 million years ago, in the Permian period. “The specimens found are characterized by petal-shaped teeth with a spatulate crown and a long root,” explained Zhikun Gai, a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences. "This crown is surrounded by an enveloping set of ridges at the base to prevent the prey from slipping." Obviously, these were predators, with the top predators at the top of the food chain.
During the Carboniferous and Permian periods, the place where shark teeth were found was part of the North China microcontinent in the paleoequatorial regions of the Paleotethis Ocean, a humid tropical climate reigned here, and in the shallow seas there was plenty of food for sharks. Bryozoans, brachiopods, gastropods and cephalopods, fusulinids, ostracods, trilobites and corals lived there.