Mushroom-shaped deep sea creature doesn't fall into any known classifications

A new genus of strange, mushroom-shaped ocean animals found off the coast of Australia has been named by scientists after nearly three decades of attempting to study and classify them.

According to National Geographic, the organisms can't be categorized under any known genus or species classifications and may, in fact, reshape our understanding of how life began on Earth.

"The animals, described for the first time Wednesday in the scientific journal PLOS ONE, cannot be classified to any existing animal group, though they resemble a few long-extinct species," wrote National Geographic's Jennifer Frazer.

University of Cambridge biologist Simon Conway Morris told the magazine, ""It's a very interesting surprise, and it poses lots and lots of questions."

Neurobiologist with the University of Florida's Whitney Laboratory for Marine Bioscience Leonid Moroz said that if these organisms, named Dendrogramma, turn out to be descendants of ancient animals, their discovery could "completely reshape the tree of life, and even our understanding of how animals evolved, how neurosystems evolved, how different tissues evolved. It can rewrite whole textbooks in zoology."

The creatures were first discovered in 1986 by biologist Jean Just, who found them in a sample of Australian ocean water taken at depths from 1200 to 3000 ft. below the surface. Less than an inch long, Dendrogramma are mushroom-shaped with a combined mouth and anus at the base of their "stalks." Their alimentary canal branches off repeatedly when it reaches the "cap" of the mushroom, an inflexible disk of tissue.

The creatures do not appear to live fixed to underwater objects or to each other, but are free-floating like plankton or diatoms. They have no obvious means of locomotion. Because the mouth is small and simple, Frazer wrote, they are believed to live on microorganisms that get snared in the mucus that surrounds their mouth opening.

Scientists have identified two species, Dendrogramma enigmatica and Dendrogramma discoides, under the genus heading Dendrogrammatidae.

The creatures are believed to be related to jellyfish, but lack the tentacles or stinging cells that jellyfish have.

When biologist Just first returned to the laboratory with the creatures, they were preserved in formalin and ethanol, which made analysis of their genes impossible. The lack of genetic data means that it is impossible to determine how they are related to other animals.

"It's still amazing that no one has come back and said at least, 'I've seen things like this,' even if they haven't published it," said Just, who is retired from the Natural History Museum of Denmark, to National Geographic "That's exciting."

[image of Dendrogramma enigmatica via Wikipedia.com]