According to scientists, life on Earth arose notless than 3.7 billion years ago. At first they were microscopic creatures, the remains of which we will never see - over an unimaginable number of years they completely decomposed and did not leave a single trace behind them. In the course of evolution, living organisms have become larger, which already allows scientists to detect their bodies - the field of science that deals with this is called paleontology. In 2018, researchers found the remains of some of the very first animals on Earth on the shores of the White Sea. These creatures had a digestive system, but for a long time scientists did not know what they could eat - it goes without saying that soft tissues did not even have the slightest chance of surviving to this day. However, in the course of studying the remains, they managed to find something that helped to reveal one of the many secrets of antiquity - the diet of ancient animals.
Kimberells are one of the first animals on Earth
The first of the most ancient animals whose diet has been studied is kimberella (Kimberella).An imprint of his body was found several years ago by an employee of the Australian National University, Ilya Bobrovsky, on one of the rocks on the coast of the White Sea. According to scientists, the age of the fossil is 575 million years. Like many organisms of the Ediacaran period, kimberells were oval flattened bodies. Below are a few images to give you an idea of what I'm talking about.
Kimberells are one of the very first, "full-fledged"animals on earth. Like modern organisms, they had a mouth and intestines for digesting food. Unfortunately, the soft tissues of these creatures have decomposed long ago, so scientists cannot study the contents of the intestines. However, in the course of new scientific work, scientists were able to study the chemical composition of the ancient Kimberella print.
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What did the animals of the ancient world eat?
Researchers from Russia and Australia have found traces in the remains of an ancient creature phytosterol. These organic substances arecell membrane of all plants, including algae. Since there was no way Kimberellas could produce this substance on their own, scientists hypothesized that they fed on microscopic algae.
Ilya Bobrovsky, mentioned above, also found another representative of the animal world of the Ediacaran period. On the shore of the White Sea, a cast of the body was found dickinsonia (Dickinsonia) is the same flattened creature,but which had a much larger size than kimberella. According to scientists, the body length of some Dickinsonia could reach 1.4 meters, that is, they were the largest animals of their time (from those known to science).
During the study of his imprint, scientists could notfind molecules of organic substances that are contained in algae cells. Dickinsonia had a wide body, so they most likely sucked up nutrients from the bottom of prehistoric seas and oceans with their entire body. Exactly what nutrients dickinsonia ate, scientists do not know, but it is definitely not algae.
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What were the oldest animals
If we compare the two found creatures,Kimberells were more developed than Dickinsonia. Despite the relatively small size of the body, they fed on algae - such food provided them with a large amount of energy. And the method of absorption of nutrients from the bottom, as in Dickinsonia, was less energetically favorable. You might think that Dickinsonia had such a large body size in order to absorb more substances, because in order to live, they needed to absorb more organic compounds.
Dickinsonia reconstruction on video
Both Kimberella and Dickinsonia became extinct towards the endEdiacaran period. After them, organisms appeared on Earth that had already begun to somehow resemble modern animals. The first predators arose, as evidenced by the holes on the bodies of some ancient organisms. But what the very first predatory creatures were, scientists do not know - they definitely were not large, because the holes from the "teeth" have a diameter of no more than 400 micrometers.
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However, there has recently been information thatthe first predator on Earth nevertheless appeared in the Ediacaran period - an imprint of its body was found in England. Judging by the ancient footprints, these creatures looked like modern coral polyps. If you want to learn more about them, welcome to this material.