Researchers have analyzed Kimberella, a slug-like organism, which contains compounds indicating it fed on bacteria and algae from the ocean floor and had a developed digestive system.
An international team of researchers has uncovered the eating habits of ancient animals on Earth, based on fossils dating back over 550 million years, according to the Guardian.
They examined the ancient fossils of the Ediacaran biota – complex life forms that existed from 538.8 to 635 million years ago. These fossils are the earliest evidence of the dietary habits of ancient animals.
Fossil of the organism Kimberella. (Photo: Ghedoghedo/CC BY-SA).
The fossil of a slug-like organism called Kimberella contains compounds indicating it consumed algae and bacteria from the ocean floor. This was not necessarily a “lavish meal,” but a sign that it had a mouth and intestines, along with a digestive mechanism similar to some modern invertebrates.
Professor Jochen Brocks from the Australian National University, a co-author of the study, stated that fossils from the Ediacaran period are “very important in the evolutionary process as they demonstrate the first strong development of life. They are the oldest large fossils that humans can see with the naked eye.”
Researchers believe that Kimberella, a symmetrical organism, could move and was an evolutionary animal of its time.
“Having a digestive system is very modern. Sponges, corals, and jellyfish do not have a normal gut throughout their bodies,” Brocks said, comparing it to more primitive animals.
“We can see that the intestines of Kimberella could actively absorb cholesterol molecules and eliminate other molecules it did not want to absorb.”
Analysis of another type of animal called Dickinsonia revealed that this second organism was less evolved as it lacked a mouth or intestines.
These fossils were collected in 2018 from cliffs near the White Sea in northwestern Russia by Dr. Ilya Bobrovskiy of GFZ-Potsdam, the lead researcher.
Previously, scientists had identified Dickinsonia as the oldest animal fossil, dating back approximately 550 million years.
In 2021, a study published in the journal Nature suggested that net-like patterns in rock samples from 890 million years ago resemble the networks of modern sponges. This helped date the earliest forms of animal life to around 300 million years ago. However, this evidence has been controversial.
Brocks noted that the new research shows the Ediacaran biota “contained some organisms that triggered the Cambrian explosion, leading to the rise of modern animals.” The Cambrian evolutionary explosion, also known as the biological explosion, occurred about 538.8 million years ago.
This study has been published in the journal Current Biology.
