Scientists have discovered two new species of a mushroom-shaped sea-dwelling creature off the Australian coast. The problem is, these tiny organisms defy the classification system used to group every life form on our planet. Researchers at the University of Copenhagen say the mushroom-shaped organisms don’t fit into any known subdivision of the animal kingdom.
The mushroom-shaped organisms resemble Ediacaran Period life forms
Such a finding is extremely rare. Jorgen Olesen, co-author of the study, said this might have happened only three or four time in the last 100 years. Findings of the study were published in the journal PLOS ONE on Wednesday. These organisms were originally collected in 1986. They measure only 1.5 centimeters in length and about one centimeter in width.
Scientists found several similarities between the mushroom-shaped organisms and soft-bodied life forms that existed on the Earth between 635 and 540 million years ago. That span of history is called the Ediacaran Period. Organisms from that period have also been difficult to categorize. Many scientists argue that they were “failed experiments in multicellular life.”
The two species of mushroom-shaped organisms have been named Dendrogramma enigmatica and Dendrogramma discoides. Body of the animals consists of a flattened disc and a stalk that has a mouth at the end. They have an inner stomach and an outer skin separated by a jelly-like material. However, their food habits, how they reproduce, and their lifestyle are still unknown. Many scientists say these could be “living fossils” from the Ediacaran Period.
DNA analysis could help classify the mushroom-shaped animals
Jorgen Olesen told BBC that his team believed the organism belonged somewhere in the animal kingdom. But where? Nobody knows. One thing that researchers can say with certainty is that these species don’t belong in the Bilateria. Bilateria is an animal grouping whose members have their bodies divided vertically into left and right halves. Humans fall in the Bilateria group.
The mushroom-shaped organisms are multicellular, but they are non-symmetrical. Scientists collected them in 1986 during a cruise near Tasmania at water depths of 400-1000 meters. But they were recognized only recently. There is a way to figure out where in the classification system these organisms belong: examining their DNA.
For that, researchers will need new specimens because the original samples were preserved in 80% alcohol, which prevents analysis of DNA.
