A team of researchers from multiple international universities found that an ancient species known as Stromatoveris psygmoglena was indeed an animal, a new study published in Palaeontology reports. Though many people assume that fossils are easy to identify, that is only the case for perfectly preserved ones. Older rocks or ones that are broken down by wear and tear, are much more of a mystery.
One such puzzle is Stromatoveris psygmoglena, an ancient organism that looked like a large ribbed leaf. While scientists have long suspected that the creatures — which existed during the Ediacaran period 500 million years ago — were animals, they could not find any evidence to support that claim.
That changed in the recent study when a team of international scientists studied all known Stromatoveris psygmoglena fossils. Such analysis revealed that, despite their appearance, the organisms were animals. They were just not like any species alive today.
The scientists reached their conclusion by using a computer model that projects the most likely place for certain species on the evolutionary tree. That system, combined with other animal data, revealed a completely new phylum that is more complex than sea sponges but less advanced than animals with full digestive systems, BGR reports.
The reason that group remained a mystery for so long is because it did not evolve into any other known organisms. In fact, the creatures rapidly died off out of nowhere after surviving for tens of millions of years.
“This branch, the Petalonamae, could well be its own phylum, and it apparently lacks any living descendants,” said lead author Jennifer Hoyal Cuthill, a researcher at the Tokyo Institute of Technology, according to Science.
Researchers are not yet sure why the species died off, and that is a mystery that may never be solved. Even so, the new findings serve as an interesting discovery that may help scientists get more insight into what the Earth was like 500 million years in the past.