Strange mushroom-like creatures found in the very deep sea off the coast of Australia have finally been named by scientists, despite the fact that they do not fit into any of the known animal groups. Researchers now suggest that this creature may inspire an overhaul of the animal family tree.

The creature, called Dendrogramma, is detailed for the first time under its new name in the journal PLOS One.

According to a study of the creature, Dendrogramma is a deep-sea dweller that slightly resembles some long-extinct species, but doesn't truly fit into modern animal classification.

Initially discovered in 1986, it was thought to be a kind of mushroom or jellyfish. However, both those theories were quickly thrown out the window when scientists realized that the "stalk" of this translucent creature ended with a mouth. The "stalk" was found to be a digestive canal that quickly branches out into the widening flesh of the animal - which looks much like a chanterelle mushroom head.

Interestingly, the study goes on to add that the tiny creature - less than an inch long - cannot swim. Instead, it is thought that they simply float through the dusky depths of the deep sea, capturing microbes with a sticky mucus that lobes around their "mouths" secrete.

Jean Just, the now-retired biologist from the Natural History Museum of Denmarke who first discovered the mysterious animal, told National Geographic that it appears to be entirely new to the scientific community.

"It's still amazing that no one has come back and said at least, 'I've seen things like this,'" he said. "That's exciting."

Exciting... and a little scary, according to Leonid Moroz, a neurobiologist who noted that the find could "completely reshape the tree of life, and even our understanding of how animals evolved. It can rewrite whole textbooks in zoology."

Just, who authored the newly published study, seems more bemused.

"We don't even know [when] they're upside down," he told Live Science.

"No other living animals have these characteristics," he added, "so they are pretty special one way or another."