WELLINGTON, New Zealand — Long before whales and great white sharks roamed the oceans, a giant shark prowled the waters near what we now know as northern Australia. This massive creature lived during the age of dinosaurs, making it the earliest known mega-predator in the lineage of modern sharks. Researchers discovered large vertebrae on a beach close to Darwin, revealing that this shark swam in the oceans 15 million years earlier than known large sharks.
The shark’s ancestor, which is similar to today’s great whites, measured about 8 meters (26 feet) long. Benjamin Kear, a paleobiologist and author of a study in Communications Biology, explained that this finding pushes back the timeline for when we see these enormous sharks in the fossil record.
Sharks themselves have a history that stretches back 400 million years. The ancestors of great whites, even in fossil records, first appeared around 135 million years ago and were much smaller at that time. This recent discovery challenged researchers’ expectations, showing that these sharks grew to gigantic sizes much earlier than previously believed.
The fossils were found along a coastline once covered by an ancient ocean that spanned from what is now Australia to parts of Europe. This area is rich in fossils, featuring other marine life like plesiosaurs and ichthyosaurs.
Interestingly, the vertebrae weren’t new finds; they were unearthed back in the 1980s and 1990s but hadn’t been studied thoroughly. Kear noted that studying shark vertebrae is crucial since sharks’ skeletons are mostly made of cartilage, making teeth the primary fossils we typically find. However, vertebrae help scientists understand the size of these ancient creatures better.
Kear explained the challenges in estimating the size of sharks from teeth alone. For instance, scientists often resort to mathematical models to gauge size, especially for big predators like megalodon, which may have reached 17 meters (56 feet).
To estimate the size of the Darwin shark, a collaborative research effort utilized data from fisheries, CT scans, and mathematical modeling. The team believes this ancient predator resembled our modern giant sharks, an evolutionary success over millions of years.
Kear emphasized that this discovery illustrates how modern sharks may have evolved early in their existence to dominate the food chain. The team plans to continue exploring environments worldwide for similar fossils, as there may be more ancient species waiting to be uncovered.
Studying these ancient ecosystems offers valuable insights into how current species might react to environmental changes. By examining past climate shifts and biodiversity, researchers could predict potential future developments, providing a clearer understanding of the natural world.
For more on the history of sharks and their evolutionary journey, check out resources from trusted sources like National Geographic.
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Fish, Sharks, Science, Animals, Climate and environment, World news, General news, Article, 128365049
