A Saber-toothed Squirrel?

I've always been fascinated by paleontology, but things change so quickly in science that it doesn't take long to get behind. When I first taught biology at South Providence (I think it was 2003) I quickly found out that MANY things were different from when I first studied it in college. (I just told my students that I went to college during the last Ice Age. I think some may have believed me!) I only taught biology for a couple years and went back to teaching math, so I've been trying to catch up a little bit lately on changes. Here are a few interesting articles I found.
 

A Saber-toothed squirrel?
A fossil found in Argentina of a small mammal will hopefully help scientists to determine if mammals evolved differently in the Americas than they did in other parts of the world. The fossil dates to approximately 100 million years ago from the Cretaceous period of the Mesozoic era, and falls into a 60 million year gap in the fossil record of South America. It is in the subclass of mammals Theria, which means it was live-bearing, as opposed to an egg-laying mammal such as the platypus. You can find an abstract of the article in Nature below. Clicking on the title above will take you to the Science News article that has an artist's rendering of what the little creature might look like. Not nearly as cute as the gray squirrels currently playing on the pecan tree in my backyard.
Nature article


Homo Sapiens may have moved faster than we think.
Two new studies have found that modern humans may have arrived in Europe earlier than previously thought, perhaps as early as 45,000 years ago. This would mean they coexisted with Neanderthals for a longer period of time. Neanderthals died out around 30,000 years ago. Both studies are based on the reexamination of previously found evidence: two teeth found in a cave in England in 1927, and three teeth in a partial jaw bone found in Italy in 1964. But other scientists are skeptical or outright disagree. To read the entire story click on the heading above. If you're way behind on human evolution, as I was, there are a series of PBS videos that explain the current thinking on the subject. They are well done and fascinating. You can find the first video, Becoming Human Part 1, here. There are three videos.

Giant Sauropods may have migrated
Sauropods were immense. The most familiar example is the Apatosaurus (what we used to call the Brontosaurus.) Henry Fricke believes that one reason they became so large is because they migrated to richer feeding grounds during certain times of years. His analysis was based chemical variations in the teeth. Oxygen in the water animals drink finds it's way into the blood stream and eventually into tooth enamel. This can be compared to samples of sediment found near the teeth. If they differ there is evidence that the animal has migrated to that area. Or so the theory goes. There is always more to investigate. That's one thing I like about science, there are always new questions.