Monday, 28 September 2015

Spectactular fossils of the Green River Formation


Large teeth and rear-placed fins make Phareodus encaustus well suited for catching and eating other fish.
Rocks of the Green River Formation contain a story of what the environment was like about 50 million years ago in what is now parts of Colorado, Utah and Wyoming.

Streams draining the steep and newly formed mountains carried large amounts of sand, silt, mud and dissolved minerals into lakes that occupied the intermountain basis. Over time the sand, silt and mud began infilling the lakes. Abundant plants grew on broad swampy areas that developed around the margins of the lakes.

This 5.5 inch long bat is the most primitive known.
Claws on each finger of its wings indicate it was probably an agile climber and crawled along and under tree branches searching for insects.
A lagerstätte is a sedimentary rock unit with fossil content. The Green River swamps and lakes provided an exceptional environment for fossil formation.

The lakes and swamps were calm where remains were quickly buried by sediment. This resulted in one of Earth's most spectacular deposits of preserved plants, animals, insects and fish.

This 1.7 meter (5 foot 6 inch) softshell turtle is one of the largest turtles from Fossil Lake. During the Eocene, trionychid turtles reached maximum size.

This fully-articulated early horse is an extremely rare find.

The insect fossils from Fossil Lake sometimes show color patterns, wing venation, and sex-related characteristics.

Palm Tree Flower
Turritella Agate is the name used for a brown, translucent, fossiliferous agate found in the Green River Formation of Wyoming. It is easy to recognize because it contains large fossil snails that stand out in a white-to-tan color that contrasts with the brownish agate.

This organic gem material was incorrectly named decades ago when the christener thought that the spectacular spiral-shaped gastropod (snail) fossils entombed within the stone were members of the marine Turritella genus. That was an error. The fossils are of the freshwater snail, Elimia tenera, a member of the Pleuroteridae family.



See ----->http://pennystockjournal.blogspot.ca/2015/08/christies-out-of-ordinary-auction.html
See ----->http://pennystockjournal.blogspot.ca/2015/06/the-burgess-shale-formation.html
See ----->http://pennystockjournal.blogspot.ca/2015/04/utahs-dinosaur-death-trap-reveals-trove.html

http://geology.com/articles/green-river-fossils/