For a long time scientists thought they knew what these 558-million year old sea creatures looked like, but new research has painted a different picture.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
Australian National University Research School of Earth Sciences researcher Ilya Bobrovskiy said he and his colleagues discovered what was once thought to be the entire Dickinsonia fossil, was more likely their "skeleton" - an impression of their more resilient tissue.
"It helps us know what they didn't look like and it will change the way we look at them," Mr Bobrovskiy said.
Dickinsonia is a genus of the Ediacara biota, strange sea creatures which lived on the seafloor 541 to 571 million years ago.
Mr Bobrovskiy said the so-called skeleton could just be a fraction of what the creature was, and some could be much more complex, with tentacles or mouths.
Dickinsonia didn't have a skeleton. Instead, they had a more resilient type of tissue.
Because Dickinsonia had so many different types of tissue - including its "skeleton" - they showed how much more complex they were than simple organisms.
This could tell scientists more about the stages of animal evolution that eventually led towards the first humans, Mr Bobrovskiy said.
Mr Bobrovskiy released his paper, co-authored with university colleague Associate Professor Jochen Brocks and Russian scientists, on Tuesday.
"It is most rewarding to get an answer for myself," Mr Bobrovskiy said.
The research took over five years and saw him abseiling down cliffs off the White Sea in north-west Russia to collect rock samples.
Originally, scientists had thought when the sea creatures died they were covered in sand that was cemented over the creature.
They believed this created a "death mask" and preserved the creature before it decayed.
But by testing the minerals in the rock samples he took in Russia, Mr Bobrovskiy and his colleagues found no trace of the minerals that would create the "death mask".
Instead he found soft sediments allowed the creatures to be preserved thanks to the low-oxygen environments on Earth at the time making the Dickinsonia rot more slowly.
As the soft sediment slowly pushed up between the decomposing creature and the layer of sand above, it created an impression of the creature's skeleton.
He said it was hard for humans to know what Dickinsonia looked like because they were so different from any other animal.
"They look completely alien to our eyes," he said.
He said humans could reconstruct dinosaurs based off what their bones looked like because we saw birds and reptiles.
But aliens from outer space couldn't guess because they wouldn't have any reference points.
"Imagine you've never seen a human being, you've never seen a dinosaur or a bird," Mr Bobrovskiy said.
"The same way we have never seen other organisms that look like the Ediacaran creatures [means we] have as much difficulty as aliens would have had with reconstructing dinosaurs."
