Tuesday, April 6, 2010
The Ethiopean Amber
Image courtesy PNAS/ Matthias Svojtka
This is really neat: the American Museum of Natural History reports the discovery of a nice chunk of Cretaceous amber from Ethiopia. While pieces of the translucent golden fossilized tree resin are well known from other parts of the world, this is the first significant piece from Cretaceous Africa. It dates to about 95 million years old, at which point Africa was an island continent separated from South America by a narrow sea. The discovery is presented in the latest issue of the Proceedings of the National Academy of Sciences.
Resin is the sticky stuff that gets all over my hands when I gather fallen pine limbs for backyard campfires. You're probably familiar with its ability to trap insects and other organic material; it played a key role in that Spielberg movie. You know the one. It was an adaptation of a novel. Not Minority Report.
Chemical analysis reveals that the resin may be derived from a flowering tree, or angiosperm, similar to members of a living group related to legumes. The Cretaceous was the period when angiosperms really diversified, and many of the lines that wound up producing today's familiar flowers, trees, and fruits and vegetables popped up. If this resin was from such a tree, it would be great, but it may alternatively be from a previously unknown kind of conifer. Such a dense piece of an ancient ecosystem contains a wealth of information, so it is being examined by scientists from more than a dozen institutions around the world. So far, they've turned up 30 insects and spiders, as well as plant material, fungi, and bacteria. It's like sending a robotic probe back in time and having it bring back a terrarium's worth of critters to study.
As pretty as it is, this hunk of fossil resin probably won't make as big of a splash as, say, a big theropod. But what it reveals about the ecosystem in which the dinosaurs of ancient Ethopia lived is arguably of much greater value than the skeleton of one creature. While big dinosaurs amp up the imagination like a shot of adrenaline, pondering the complicated interactions of every member of the ecosystem gives a more sustained rush, a point Scott Sampson makes very nicely in Dinosaur Odyssey. It used to be common to plop dinosaurs into Mordor-like wastelands of fuming volcanos, maybe throwing the odd palm tree into the background. Thanks to discoveries like this, that lazy old image is just about dead.