| Here are some mystery fossil specimens from the Late Miocene-Pliocene Coso Formation of Inyo County, California--a terrestrial geologic rock deposit which has yielded to vertebrate paleontologists an important Blancan Stage mammalian fauna roughly 4.8 to 3.0 million years old. A few years ago, I ran across a rather nicely exposed section of the Coso Formation that yielded many wonderfully preserved "cabbage"-shaped algal bodies before the Coso Range Wilderness had been established. Directly across the road from the algal site was an outcropping of sandstones and shales which contained the curious, mysterious "twig-like" bodies shown in the image above (the circular, ring-like, blackish body at the lower right is rather provocative, as well--but, what is it?); the "twigs" are embedded in an apparently ostracode-rich sandstone (many of the minute bean-shaped whitish bodies in the matrix look very similar to fossil ostracodes, a minute bivalve crustacean). So, what exactly are these "twigs?" Freshwater sponge fossils? Algal remains? Or, are they simply fossil twigs, or even tiny roots, from ancient plants? Any help in identifying these mystery "twigs"--the longest of which is 17 millimeters in length--would be greatly appreciated. |