Fossil vertebrates have been known from the flanks of a large volcano in the Doupov Mountains of northwestern Bohemia since at least 1690, when the remains of freshwater fish and the first known fossil rodent were discovered.  In addition to vertebrates, fossils known from this area include leaves, seeds, and nuts, and molluscs.  The age of the fossils is about 37 or 38 million years old.  Recently, marks on vertebrate bones have been recognized as termite traces, similar to those found on fossil bones at Laetoli, Tanzania, from rocks of about 4 million years old.  In addition to insect traces on bones, there are also teardrop-shaped brood cells or cocoons of solitary burrowing insects, and two years ago the remnant of a fossilized termite colony was discovered.  The distribution of fossil plants, molluscs, and insects over the ancient landscape indicates a mosaic pattern of wetter and drier environments, with the southern slopes of the Doupov volcano rather dry and sparsely vegetated.