Natural History - Aquamarine Topaz Pebble Group [50]

The fang tooth with a section of the jaw, set on a sandstone matrix. 508 grams, 14.2 cm



From Morocco, North Africa. From a Lincolnshire, UK, collection.

The Enchodus fish is an extinct genus of bony fish. It flourished during the Upper Cretaceous and later and was small to medium in size. One of the genus's most notable attributes are the large 'fangs' at the front of the upper and lower jaws and on the palatine bones, leading to its misleading nickname among paleoichthyologists, 'the saber-toothed herring'; these fangs, along with a long sleek body and large eyes, suggest Enchodus was a predatory species.

Diplomystus sp. specimen on a rectangular matrix. 307 grams, 17 cm



From Wyoming (Green River Formation), USA. From an old Bristol, 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 composite plate containing a large number of variously sized ammonites, polished upper face. 835 grams, 24.7 cm



From Madagascar. From a Lincolnshire, UK, collection.