According to scientists at the Australian National University (ANU), the content of the last food eaten by the earliest known animals – which inhabited the Earth more than 550 million years ago – has uncovered new clues about the physiology of our ancient animal ancestors.
Animals belonging to the so-called biota of the Ediacaran period 575 million years ago were the oldest large organisms in the world. ANU researchers, as reported in a press release from the institution, discovered that these animals were feeding on bacteria and algae from the sea floor.
conclusions, Published in this Tuesday’s Journal Current Biology, reveal more information about these strange creatures, including how they were able to consume and digest food. Scientists analyzed ancient fossils that preserved phytosterol molecules (natural chemicals found in plants) from the animals’ last meal.
By examining the molecular remains of what they ate, the researchers were able to confirm that the slug-like organism, known as Kimberella, had a mouth and gut and processed food much like modern animals. They say it was probably one of the most advanced Ediacaran organisms.
Another animal, which grew to 1.4 meters long and had a rib-like pattern on its body, was less complex and had no eyes, mouth or gut, the ANU team found. Instead, a strange creature called Dickinsonia used its body to absorb food as it traversed the ocean floor.
“Strange Bugs”
“Our findings suggest that the biota of Ediacaran animals that lived on Earth before the ‘Cambrian explosion’ of modern animal life was a mix of oddballs like Dickinsonia and more advanced animals like Kimberella that they already had. Physiological traits similar to humans and other living animals,” says lead author Ilya Bobrovsky of the GeoForschungsZentrum in Potsdam, Germany.
Both Kimberella and Dickinson, which have a different structure and symmetry than today, are part of the Ediacaran family of biota that lived on Earth about 20 million years before the “Cambrian Explosion,” a major event that changed the world forever. The course of evolution throughout life on Earth. In 2018, Bobrovsky discovered both Kimberella and Dickinsonia fossils from steep cliffs near the White Sea in northwestern Russia in the Arctic Ocean.
“Ediacaran organisms are truly ancient fossils and large enough to be visible to the naked eye. They are also the origin of us and all animals that exist today. These creatures are our deepest and most visible roots,” says Bobrovsky, who conducted the research as part of his PhD at ANU.
Study co-author Professor Jochen Brox, from the ANU Research School of Earth Sciences, said the algae are rich in energy and nutrients and may be crucial to the growth of the Kimberella. “Energy-rich foods could explain why organisms in the Ediacaran biota were so large. “Almost all early fossils were single-celled and microscopic in size,” says Professor Brox.
Ediacaran organisms are the origin of us and all animals that exist today. These beings are our deepest and most visible roots.
Ilya Bobrovsky
Using advanced chemical analysis techniques, ANU scientists were able to extract and analyze the sterol molecules contained in the fossil tissue. Cholesterol is a characteristic of animals. just like that In 2018, an ANU team was able to confirm that the Ediacaran biota is among our earliest known ancestors.
The molecules contained signals that helped researchers decipher what the animals ate before they died. Professor Brox notes that it was difficult to differentiate the signals from molecules of the creatures’ own fat, the remains of algae and bacteria in their guts, and molecules of decomposed algae from the ocean floor that were found together in the fossils.
“Scientists already knew that Kimberella had left food marks in the algal crust that covered the sea floor, suggesting that the animal had a gut. “But it was only after analyzing the molecules in Kimberella’s gut that we were able to determine exactly what she was eating and how she was processing the food,” says Brooks. “Kimberella knew exactly which sterols were good for her and had an advanced gut to filter out the rest.”
“It was A Eureka moment for us; Using chemistry preserved in fossils, we can now make the contents of an animal’s gut visible, even if the gut has long since disintegrated. We then applied the same technique to more unusual fossils, such as Dickinsonia, to understand how it fed, and discovered that Dickinsonia had no gut.
Source: El Diario
