The “last meal” eaten by some of the earliest known animals has helped scientists uncover new clues about some strange ancient creatures that are our animal ancestors, according to the Australian National University.
The Ediacaran biota, the life forms present on Earth during the Ediacaran period about 575 million years ago, are some of the oldest large organisms in the world. For the research study published in Current Biology, scientists analyzed ancient fossils containing preserved phytosterol molecules. Phytosterol molecules are chemicals found in plants that were left in the fossils of the last food eaten by animals.
Kimberella
The researchers analyzed the molecular remains of what they ate and were able to confirm the physiology of a slug-like organism called Kimberella. According to the study, it had a mouth and gut and digested food the same way modern animals do. According to the Australian National University, it was probably one of the most advanced creatures on the planet during the Ediacaran period.
A fossil of Dickinsonia, which grew up to 1.4 meters. (Image credit: Ilya Bobrovskiy / Australian National University)
Dickinsonia
The research team found that Dickinsonia, another organism that grew up to 1.4 meters long, had a “rib-like design” on its body. It was not a very complex creature and had no eyes, mouth or gut. Instead, the curious creature crawled across the ocean floor and absorbed food through its body.
“Mixed Bag of Chillies”
“Our findings suggest that the animals of the Ediacaran biota, which lived on Earth before the ‘Cambrian explosion’ of modern animal life, were a mixture of exotic animals, such as Dickinsonia, and more advanced animals such as Kimberella that already had some physiological properties similar to humans and other animals today,” lead author Ilya Bobrovskiy of GFZ-Potsdam in Germany said in a press release.
The “Cambrian explosion” Bobrovskiy refers to is a period of about 538.8 million years when almost all the major phyla (groups of related animal species) began to appear in the fossil record. Both Kimberella and Dickinsonia lived on Earth about 20 million years before the Cambrian explosion and have structures unlike anything that exists on Earth today.