The largest sharks ever to live in the oceans left their young in shallow, warm water, where there was plenty of food and few predators. However, with climate change, there are fewer and fewer places for sharks to grow up. Perhaps this is what led to their extinction.
According to a study published in the Royal Society of Biology Letters’ journal, it was the shrinking of places where megalodon sharks could mature that may have contributed to their extinction within 20 million years.
Otodus megalodon – sometimes classified as the Carcharocles megalodon – took 25 years to become an adult. This is “extremely delayed puberty,” the authors write in a research article. However, when the shark was fully grown, it could reach 18 m.
The Megalodon was the most dangerous predator in its existence and even fed on sharks and even whales. This ancient shark had no competitors among predators. But his cubs were vulnerable to attacks from other predators, such as other sharp-toothed sharks. Shallow continental shelves with small fish for food, where predators were almost absent, were ideal places for the offspring of megalodons.
The research team discovered a nursery area off Spain’s east coast after visiting a museum and observing a collection of megalodon teeth. Many of them were very small for such a large animal. Judging by the teeth’ size, they suggested that the site was once home to young megalodons.
According to the authors, the Spanish nursery can be described as “the perfect place to grow.” It would be “a shallow bay with warm waters, connected to the sea, with extensive coral reefs and many invertebrates, fish species, marine mammals and other sharks and rays.”
The researchers analyzed eight other sets of shark teeth previously collected and distributed in the United States, Peru, Panama, and Chile. They concluded that four of them – two in the United States and two in Panama – belonged to younger sharks. As a result, the authors suggest that these four regions could also be nurseries for megalodons. It is worth noting that sharks are constantly losing teeth throughout their lives.
Megalodons were comfortable in the Miocene period’s warm and temperate waters, which lasted from 5 to 23 million years ago. But the cooler Pliocene period was fatal for sharks, the authors conclude. The significant reduction in shallow water nurseries due to the loss of sea level caused by the cooler climate may have contributed to the megalodon’s eventual extinction.