Today, the ocean covers more than half the planet's surface and is home to an incredible number of species, including the Earth's most fearsome predators: killer whales, sperm whales and great white sharks. But millions of years ago, in the ancient ocean, things were completely different and scientists believe that today's predators were not at the top of the food chain, writes Science Alert.

During the Early Cretaceous period, about 130 million years ago, biodiversity flourished, both on land and in the ocean.. The ancient oceans had much higher water levels and were home to monstrous predators unlike anything alive today..

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In a new study, the team from the University of McGill deeply plunged into one intriguing ecosystem of the early Cretaceous period, where sea reptiles with a bus with a bus hunted for other large carnivorous animals. The authors of the study believe that they formed a rare seventh trophic level in their food chain.

Note that modern oceans reach a maximum of the fifth or sixth trophic level, represented by higher -order predators. The trophic level indicates the position in the food chain: the lower the level - the closer the animals to the base of the chain. For example, at the first level there are primary manufacturers - algae and plants, on the second - primary consumers, for example, herbivores. The third is for predators that eat herbivores, and the higher levels are for predators that hunt other predators.

In their work, scientists focused on studying the ancient inhabitants of the Paha Formation, a geological formation of the Early Cretaceous period located in the territory of modern Colombia. It is known that at that time the ocean level was much higher, and therefore most of this territory was covered by a warm, shallow sea.

The study authors believe the sea was likely teeming with life at all trophic levels at the time, part of a broad surge in biodiversity during the Cretaceous period caused by the breakup of the supercontinent Pangea and a warm climate..

It takes a diverse, healthy ecosystem to support high-level apex predators, and the dynamism of this prehistoric sea allowed some incredible leviathans to evolve. The Paja ecosystem is known to have been home to giant dolphin-like reptiles such as ichthyosaurs, as well as crocodile-like beasts, teleosaurs, and long-necked pliosaurs, some of which reached more than 10 meters in length.

The team notes that the potential of the seventh trophic level shows how rich and complex the Paja ecosystem may have been around 130 million years ago. To shed light on this ancient habitat, researchers reconstructed its ecosystem network using a model of interactions between species in an ecosystem. For this, the team used the fossil remains of famous animals previously found in the groin formation.

During the study, key details were taken into account, such as the size of the body of animals and food adaptations. Scientists also used analogues from modern wildlife, which helped the team derive some non -puncture information.

Note, earlier this approach was mainly used to study modern ecosystems, but recently scientists also apply it to fossil. Researchers drew inspiration from the existing network of naval ecosystems based on the modern ecosystems of the Caribbean and used this reference model to check and configure their groin network.

When the model was completed, it provided an unprecedented look at one of the most vibrant marine networks known to science.. According to study co-author Dearly Cortez, a biologist at McGill University, her and her colleagues' work provides a broader understanding of ecology, both ancient and modern.. Understanding this complexity helps us to track how ecosystems develop over time.

Previously, Focus wrote that scientists have created the most modern reconstruction of ichthyosaurus.