More than two decades ago, when Elizabeth Turner was still a graduate student studying fossilized microbial reefs, she hammered out hundreds of lemon-sized rocks from weathered cliff faces in Canada’s Northwest Territories. She hauled her rocks back to the lab, sawed them into 30-micron-thick slivers—about half the diameter of human hair—and scrutinized her handiwork under a microscope. Only in about five of the translucent slices, she found a sea of slender squiggles that looked nothing like the microbes she was after.
Contrary to popular belief, becoming a fossil can be easy instead of hard, and fossils can be abundant instead of rare. It all depends on what an organism is made of, where it lives and dies, and what happens next in the dust-to-dust process—preservation or natural recycling. Continue reading How Do Fossils Form?
Hundreds of millions of years ago, massive ice caps sheathed Earth’s continents from coast to coast. Only the peaks of the planet’s mountains stood above the ice as glaciers ground and crushed their way through the bedrock, meandering slowly toward the snow-covered plains. Where the glaciers met the oceans, huge blocks of ice and rock calved from the glaciers and dropped into the sea. Life, mostly algae, cyanobacteria and other bacteria, somehow persisted in the small ice-free pockets of ocean water. Like an icy planet in a distant solar system, Earth during its formative years, a juvenile phase known as the “Snowball” Earth, was a far different place than the mostly blue planet of today. Continue reading How Does Earth’s Carbon Cycle Work?
Bones from an extinct short-faced bear and a wolf-life carnivore are among the many fascinating remains pulled from a submerged cave in Mexico. The discoveries provide a glimpse into the kinds of animals that lived in Central America during the last Ice Age. Continue reading Treasure Trove of Ice Age Animal Remains Found in Submerged Mexican Cave
For decades, scientists have speculated about when exactly the bipedal apes known as Homo sapiens left Africa and moved out to conquer the world. That moment, after all, was a crucial step on the way to today’s human-dominated world. For many years, the consensus view among archaeologists placed the exodus at 60,000 years ago—some 150,000 years after the hominins first appeared.
Conventional wisdom says that brains don’t fossilize, but these seven fossilized brains beg to differ.