Natural History - Fossil Orthoceras Column

The rectangular matrix containing four Knightia alta sp. fish. 955 grams, 24.2 cm



From the Green River Formation, Wyoming, USA. Ex 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.

A cut slice of scarce achondrite from the diogenite group recorded as: Northwest Africa 5480; displayed in a Swiss membrane box. 11.7 grams, 48 mm (58 grams total, 99 x 75 including case)



From the Sahara, N.W. Africa. Ex Hupe collection, U.S.A. From a Leicestershire, UK, collection.

The total known mass of the meteorite found in Mali was 4.91 kg. Mineralogically, the diogenites are primarily composed of magnesium-rich orthopyroxene, with minor amounts of plagioclase and olivine. The pyroxenes are usually coarse-grained, suggesting a cumulate origin for the diogenites in magma chambers within the deeper regions of Vesta's crust. The achondrites of this group are named after a 5th century B.C. Greek philosopher Diogenes of Apollonia, who was the first to suggest that meteorites originate from outer space.

A freestanding display comprising two Mellitella sp. ammonites showing well preserved ribs. 9.6 kg, 31 cm



From a Cambridgeshire, UK, collection.