The megalodon shark went extinct because it was robbed of its job by the great white shark? Scientists find the truth in shark teeth
The megalodon is one of the largest carnivores that have ever lived on Earth, but the reason for its extinction has been controversial.
Recently, a study published in Nature Communications analyzed the stable isotopic ratio of zinc in the teeth of megalodons and great white sharks, and found that the extinction of megalodon sharks is likely related to the great white shark's competition for food resources.
In previous studies, the scientists were concerned with the zinc that was mixed in during the formation of animal tooth enamel, so they established a database of zinc isotopes for shark teeth, studying 20 extant shark species (including aquariums and wild individuals) and 13 fossil species, including megalodon sharks.
They found that shark teeth retained zinc isotopes (this zinc isotope value shows the trophic level of the species) in shark teeth regardless of geological age, meaning that megalodons and great white sharks overlapped in nutrient levels when they coexisted in the early Pliocene, so it was likely that they would need to compete for the same food resources.
Scientists point out that there are many potential causes for the megalodon's extinction, including climate and environmental changes, but competition with great white sharks may be one of the factors.
The research team believes that the trophic grade of an animal marks its position in the ecosystem, and the zinc isotope is a promising tool for studying the diet, ecological characteristics, and evolution of other fossil marine vertebrates, and that understanding the animal's diet plays an important role in understanding its lifestyle and ecological characteristics, and may help find clues to the extinction of animals. #Nature##海洋 #
