Natural History - Large Cut Agate Specimen Group [3]

From the lower jaw, displaying two teeth from Prognathodon sp.; repaired. 147 grams, 96 mm



Found in the phosphate mine region, Khouribga, Morocco. Acquired 1950s-1960s. From an old Bristol, UK, palaeontological collection.

The crystals with a silver-coloured setting and pendant loop; housed in a perspex box. 172 grams total, 58 x 40 mm each including case



From Brazil. Ex Mineral Imports, London, UK. Gregory, Bottley & Lloyd (Gregory's).

The square sandstone matrix with two Knightia alta fossil fish specimens. 507 grams, 16 x 13 cm



From a Lincolnshire, UK, collection.

In southwest Wyoming (and parts of Colorado and Utah) in the Green River Formation are found some of the world's most outstanding specimens of fossil fish. The Green River system was composed of three lakes: Lake Ulinta, Lake Gosiute and Fossil Lake. These Eocene lakes lay in a series of intermountain basins formed by geological events that uplifted the Rocky Mountains during the early Tertiary time. The climate was much different from the desert-like climate of this area today. Both the fauna (crocodiles, alligators, boa constrictors and some subtropical fish families) and the flora (such as large palm trees) indicate a climate much like that found along the Gulf Coast today. Large amounts of ash found in the sediments indicate that volcanoes were particularly active at this time.