Natural History - Grade A Cut and Polished Agate Slice Collection with 'Eyes' [4]

Priscacara liops fish in rectangular matrix. 613 grams, 18.5 cm



From Wyoming (Green River Formation), USA. 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.

Polished irregular-shaped specimen with insect inclusion. 0.21 grams, 25.5 mm



From a North American collection. Property of an East Sussex, UK, gentleman.

Two front leg bone sections from the Dinosaur Deltadromeus agilis; one repaired. 389 grams total, 75-86 mm



From the Kem-Kem Basin, Morocco, North Africa. From an old German paleontological collection.

Deltadromeus meaning 'delta runner' has extraordinarily delicate and long limbs making it one of the fastest dinosaurs to have existed. This meat-eating dinosaur is an early off-shoot of the theropod line on northern continents that gave rise to Tyrannosaurus and the raptor Deinonychus.