Slate has an interesting piece on som erecent dinosaur finds in Argentina:
Paleontologists announced on Monday that they had discovered the remains of a 105-foot-long dinosaur on the banks of a lake in the Argentine portion of Patagonia. The Futalognkosaurus dukei ranks among the largest known dinosaurs, along with two other species whose remains were discovered in Patagonia, the Argentinosaurus and Puertasaurus reuili. Why are all the biggest dinosaurs found in Patagonia?
They died at the right time in the right place. Patagonia happens to be an excellent place to find fossils from the Cretaceous Period, when dinosaurs reached their largest sizes. (The extinction of the dinosaurs occurred at the end of the Cretaceous, about 65 million years ago.) Because of natural uplift and erosion, sediment that dates from this time is exposed at the surface in the region’s desert badlands. This makes fossilized bones easier to spot and excavate. (Fossils are also easy to find in the badlands of the Dakotas, Wyoming, and Montana, as well as in Mongolia’s Gobi Desert.)
Interesting stuff, and a useful reminder of the fickleness of the fossil record. I’m always a bit amazed when creationists point to gaps in the fossil record as some sort of indictment of evolution. Considering all the lucky breaks you need for any ancient critter to not only be fossilized in the first place, but then wind up in a place where it can be found by scientists, it’s incredible we have any fossils at all!