Mushroom-shaped animals that look more like something from a pizza than the animal kingdom have been discovered in deep water off the coast of Australia.
The unusual organisms, described in the latest issue of PLoS ONE, appear to be “living fossils,” a term that refers to animals whose only known relatives are extinct and in fossil form.
Co-author Jørgen Olesen, an associate professor and curator at the Natural History Museum of Denmark, explained in a press release that the creatures are “new mushroom-shaped animals discovered from the deep sea that could not be placed in any recognized group of animals.”
He added, “Two species are recognized and current evidence suggests that they represent an early branch on the tree of life, with similarities to the 600 million-year-old extinct Ediacara fauna.”
The Ediacara fauna (also known as the Ediacara biota) consisted of enigmatic tubular and frond-shaped organisms that were mostly immobile, living their lives attached to something, on par with today’s barnacles on boats. They lived during the Ediacaran Period from around 635–542 million years ago.
The new mushroom-shaped creatures, named Dendrogramma enigmatica and Dendrogramma discoides, are very much alive, though. Olesen, lead author Jean Just from the University of Copenhagen and their colleagues found the animals living around 3,281 feet below the surface on the south-east Australian continental slope.
The researchers describe them as being “multicellular and mostly non-symmetrical, with a dense layer of gelatinous material between the outer skin cell and inner stomach cell layers.”
Just and colleagues think the organisms could represent the living ancestors of a mostly early failed attempt — dating to the Pre-Cambrian era — at multi-cellular life.
The bad news is that the researchers originally preserved the specimens in 80 percent ethanol, which makes them unsuitable for molecular analysis. They hope to retrieve more specimens, though, which hopefully will reveal more.
Photo: The new mushroom-shaped organisms Dendrogramma enigmatica and Dendrogramma discoides. Credit: Just et. al.