Here\u2019s what you\u2019ll learn when you read this story:<\/p>\n
Scientists believe they\u2019ve deduced why prehistoric Ediacara Biota fossils have remained preserved for millions of years.<\/p>\n
The fossils of these soft-bodied creatures from before the Cambrian Explosion have perplexed scientists for generations.<\/p>\n
Experts now believe that sand buried the organisms, which aided in the unusual preservation of the fossils found across the world.<\/p>\n
Scientists still aren\u2019t sure what exactly prehistoric Ediacara Biota fossils<\/a> tell us about life before the Cambrian Explosion<\/a>, but at least they now understand why we have a remarkable fossil record of these peculiar soft-bodied organisms nearly 600 million years later.<\/p>\n Based on our understanding of how fossils are formed, the Ediacara Biota shouldn\u2019t still be around for us to look at today. Organisms lacking hard shells and bones rarely get preserved in the fossil record<\/a>\u2014they\u2019re often erased (usually by powerful waves and storms) before the biological remains can fossilize.<\/p>\n However, that\u2019s not the case with the Ediacara Biota\u2014Earth\u2019s earliest fossilized ecosystem of complex macroscopic organisms. Spotted across the globe, they\u2019ve puzzled scientists for generations simply because of their existence. While the uniquely shaped soft-bodied organisms should have been washed away, they have instead endured as part of the fossilized record.<\/p>\n \u201cThe Ediacara Biota look totally bizarre in their appearance,\u201d Lidya Tarhan, paleontologist at Yale University, said in a statement<\/a> from the Geological Society of America. \u201cSome of them have triradial symmetry, some have spiraling arms, some have fractal patterning. It\u2019s really hard when you first look at them to figure out where to place them in the tree of life.\u201d<\/p>\n Scientists believe the Ediacara Biota existed tens of millions of years before the so-called Cambrian Explosion, a period that began about 539 million years ago and was characterized by a sharp increase in the diversity of animal life<\/a>. While scientists aren\u2019t sure what may have triggered the Cambrian Explosion\u2014theories range from a sudden event to a \u201clong fuse\u201d lead up, as Tarhan said\u2014the Ediacara Biota may help them decipher how Earth\u2019s ancient lifeforms began their great diversification.<\/p>\n Before mining clues from the fossils, scientists needed to know how they even formed to begin with. In a study published<\/a> in the journal Geology, Tarhan\u2019s team described how they used chemical analysis to research lithium isotopes<\/a> from samples collected from both sandy and muddy sediments in Newfoundland, Canada. Results showed that certain clay particles were present in the sediment covering the organisms, providing a surface on which new clay could form, directly within the seafloor and around the already-buried organisms.<\/p>\n