For our final episode on the topic of natural history, we take a look at the Pleistocene. This epoch was the most recent ice age, and toward the end of this time, lots of the largest land mammals went extinct, while in the middle of the epoch, humans finally arrived on the scene. Continue reading Ep 193: The Pleistocene Ice and rat poo→
Today we chat about the Miocene. During this epoch, kelp forest spread along the shoreline, creating habitat for otters and pinnipeds. The climate cooled and forest gave way to open grassland. Those grazing animals without the right kind of teeth died out, and the early apes diversified. Toward the end of the epoch, the branch of apes that would give rise to humans appeared. Continue reading Ep 189: The Miocene, the right teeth for the right job→
The fossil record contains, at best, only a few percent of any given ecology during any given time. To complicate the picture, some of the fossils are fakes. From money to reputation to jokes, there are many reasons why such fossil hoaxes are perpetrated. Today we look at a few examples of, and motivations for, false fossils. Continue reading Ep 159: Pulling the bone over their eyes→
In the mid 1800/s some fossils were found in a tributary of the Illinois river, called “Mazon Creek.” They had simply weathered out of the ground, but it wasn’t until coal mining moved in, that the true extent and value of the Mazon Creek fossil deposit was discovered. Continue reading ep 158: Digging for coal and fossils→
When a creature dies and becomes buried, sometimes its remains can completely rot and dissolve away, leaving a hollow space within the rock called a mold. If that mold becomes filled with sediment and water, it can harden into rock, becoming a cast. Every so often, the same sort of process can happen within the body of an animal, providing a stone cast of some of its internal arrangements. If that happens within the brain case of a skull, it’s called a brain cast. In 1924, a brain cast found in South Africa caught the attention of British anatomist Raymond Dart. After removing the fossil from the rock with his wife’s knitting needles, he was left with the first few skull fragments of Australopithecus africanus, or “southern ape of Africa,” to be discovered. Continue reading Ep 157: Fossil casts and molds→
The semiprecious stone amber is fossilized tree resin. Sometimes, insects and other small critters are trapped by sticky tree sap, and become encased in amber. Sometimes, microorganisms are found inside amber. Sometimes, they’re yeast that can be revived and used to brew beer.
Here’s an article about the yeast, revived and used to brew beer.
It took a bit of digging, but I found out why the domestic dog fossil found with the remains of the La Brea woman didn’t cause more of a sensation. Using carbon 14 dating, the dog fossil turned out to be around seven-thousand years younger than the fossil of the woman. What is carbon 14 dating, and how does it work? Continue reading Ep 154: Mystery solve, and dating fossils→
The La Brea Woman was found in close association with the remains of a domesticated dog. Her remains have been dated to between 9,000 and 10,000 years ago. Were there dogs that early in North America? How long ago were dogs domesticated? Continue reading Ep 153: Wait… she had a dog?→
Fossils aren’t just remains of animals. Some of them are materials and marks left by organisms as they went about their lives. Called “trace fossils,” they are, instead of a snapshot of death, a snapshot of life.
Here are some articles about the traces humans left on our moon.