Home » Posts tagged 冒险

Paleontologists ID Ancient Animal Masquerading as a Plant

first_img Egg Fossils Provide Glimpse Into Prehistoric ParentingBoy Uncovers Rare Woolly Mammoth Tooth Outside Ohio Resort Stay on target Ediacaran organisms have long puzzled scientists: Are they a form of algae, fungi, or some other plant?The ancient life forms—common in the Earth’s oceans half a billion years ago—may actually have been something entirely different.Two paleontologists recently revealed that the identity of the mysterious creatures: animals.Since first discovering Ediacaran organisms in 1946, scientists have identified some 200 types within fossilized rocks around the world. Their unique bodies—branched fronds with a repeating pattern—are easy to recognize.But not, it turns out, easy to catalog.Jennifer Hoyal Cuthill and Jian Han, however, uncovered “key evidence” that the Ediacaran organisms were in fact animals, and not, as previously speculated, shrubbery.The pair analyzed more than 200 fossils of a 518-million-year-old marine species called Stromatoveris psygmoglena. Paleontologists had already classified the 10-centimeter-tall species an animal, based on its environment and similarly preserved findings.A fossil of one of the 200 types of Stromatoveris (via Jennifer Hoyal Cuthill)“I began thinking: My goodness, I’ve seen these features before,” Hoyal Cuthill, of the Tokyo Institute of Technology and the University of Cambridge, said in a statement published by Science.She and Han, from China’s Northwest University, make the case that S. psygmoglena was also an Ediacaran organism—a rare “survivor” of the Cambrian explosion.Upon further examination, the colleagues found Stromatoveris and other Ediacaran organisms are quite strange indeed; they don’t belong to any living animal group.Rather, they “cluster on their own branch in the animal evolutionary tree,” the team reported in the journal Palaeontology.The Petalonamae branch—which falls between sponges and complex animals with a digestive cavity (worms, mollusks, vertebrates)—”could well be its own phylum, and it apparently lacks any living descendants,” according to Hoyal Cuthill.The case is not closed yet, though.As Science pointed out, Ediacaran organisms’ demise has been linked to the appearance of animals in the Cambrian Explosion. But that doesn’t make sense if Ediacaran organisms were animals themselves—some still alive tens of millions of years later.“It’s not quite so neat anymore,” Hoyal Cuthill said. “As to what led to their eventual extinction I think it’s very hard to say.”Let us know what you like about Geek by taking our survey.last_img read more

Continue reading