Problems with classification
They were also compared to modern-day Cnidarians, Polychaetes, and Turbellaria. Because of the prominent central part, they were also seen as Chordates. Because of their feeding habit, they were classified as similar ot the Placozoa. It was suggested, that they lived in symbiosis with organisms doing photosynthesis, and were possibly comparable to modern-day Lichen; if the mechanism worked the same as in modern-day lichens, they would be fungi.
Dickinsonia are animals
A study published in 2018, has shown Dickinsonia were animals.
- "The fossils contained almost exclusively cholesteroids, a marker found only in animals... Thus, Dickinsonia were basal animals. This supports the idea that the Ediacaran biota may have been a precursor to the explosion of animal forms later seen in the Cambrian, about 500 million years ago".
Very little cholesterol was found outside the specimen in the surrounding rock. The Ediacara biota (571 million to 541 million years ago) is the first complex organisms in the geological record large enough to be seen without magnification.