Weird deep-sea animals discovered off the coast of Australia in the 1980s have finally been classified, and they’re like no animal alive today. The newly described species, discovered between 400 and 1,000 metres below the ocean off the coast of Tasmania back in 1986, have been named Dendrogramma enigmatica and Dendrogramma discoides. And they’re so unique that they don’t fit into any existing animal groupings – in fact, they appear to most closely resemble long-extinct organisms that lived in the Ediacaran period, between 635 and 540 million years ago.
The species have been described by scientists from the University of Copenhagan in PLOS ONE this week, and their discovery could completely rewrite the bottom branches of the animal family tree. The multicellular organisms are just a couple of millimetres long and look like mushrooms, with a mouth at the end of their “stalk”. This is their only digestive opening, and it leads to a digestive canal that then branches out once it reaches the mushroom’s “cap”. They also have a dense layer of gelatinous material between their skin and inner stomach cell layers, the journal article explains.
The animals’ mostly non-symmetrical body plan is unique, which means they’re not part of the Bilateria group, one of the main animal groupings that includes humans. “Finding something like this is extremely rare, it’s maybe only happened about four times in the last 100 years,” co-author Jorgen Olesen told the BBC. “We think it belongs in the animal kingdom somewhere; the question is where.” Via Weird mushroom-shaped animals may rewrite animal family tree