This is Scientific American's 60-second Science, I'm Susanne Bard.Half a billion years ago, there existed a wormlike creature the size of a grain of rice.And a new study finds that this animal may have been the first to crawl around the seafloor,gobble up organic matter at one end and poop it out the other end.The creature, dubbed Ikaria wariootia, was probably one of our oldest relatives."Ikaria is maybe the oldest bilaterian animal that we find in the fossil record.So this is twice as old or more than things like dinosaurs."University of California, Riverside paleontologist Scott Evans.He says animals like sponges are even more ancient, but they lack the bilateral symmetry that characterizes most animals today."So a front and a back and a symmetrical left and right side.And bilaterians also have an opening for food to go in, an opening for waste to go out and a gut connecting them, basically a tube.And really, most animals, everything from insects to mammals to us, those are all bilaterians that are around today."Evans and his colleagues discovered the humble creatures in fossil layers from the Ediacara Hills of South Australia.They used 3-D laser scanners from NASA to make high-resolution images of Ikaria and the surfaces they lived on.The scans confirmed the animals' bilateral body morphology and revealed the shape of the burrows they left from scavenging the seafloor.
