| A geologist is examining strata in the Lower Mississippian Tin Mountain Limeston, Funeral Mountains, Inyo County, California--an area that lies on BLM (Bureau of Land Management)-administered public lands and is therefore open to hobby collecting of reasonable amounts of common invertebrate fossils. This is in fact famous member t2, which is a medium dark gray limestone that weathers to shades of medium gray; brachiopods are common near the base, while corals become more abundant toward the top, with microfossils--foraminifers (single-celled animals that secreted a geometrically intricate shell) and conodonts (minute tooth-like structures--unrelated to modern jaws or teeth--that served as a unique feeding apparatus in an extinct lamprey-eel-like organism)--associated with both the brachiopods and coelenterates. Relative prevalence of corals in unit t2 is best judged by the fact that all five of the following forms show up in most collections secured from it: Rylstonia, Homalophyllites, Syringopora, Vesiculophyllum, and Caninia. Photograph courtesy James St. John. |