Images Dated 25th April 2008

FG-CD-99 Dinosaur geology: Sedimentary sequence at Ghost Ranch, New Mexico

FG-CD-99
Dinosaur geology: Sedimentary sequence at Ghost Ranch, New Mexico
Triassic Chinle Formation (red, foreground); Jurassic Entrada Formation (red/white cliffs); Jurassic Morrison Formation (slopes); Cretaceous Dakota Sandstone {upper cliffs). Aside for having been the residence of the artist Georgia O'Keeffe, Ghost Ranch, near Abiquiu, New Mexico, is also famous for the discovery of a mass mortality site of the dinosaur "Coelophysis". An expedition of the American Museum of Natural History led by Edwin Colbert found the site in 1947. Coelophysis was a small carnivorous dinosaur of the late Triassic.
Francois Gohier
Please note that prints are for personal display purposes only and may not be reproduced in any way

© Francois Gohier / ardea.com

FG-CC-144

FG-CC-144
Dinosaurs - Geology: the Cretaceous-Tertiary boundary (KT boundary)
The site is in the Red Deer River Valley, Alberta, Canada.
Sixty five million years ago an asteroid or comet collided with Earth at the tip of the Yucatan Peninsula. The material ejected from Earth as a result of the impact (pulverised terrestrial rocks and pulverised fragments of the bolide) fell back to earth, forming a thin layer that has been found at many sites around the world. It is usually a one to two-centimeter thick layer of clay, rich in the element iridium.
Many paleontologists think the global catastrophy triggered by the impact caused the extinction of the dinosaurs as well as of many marine reptiles and invertebrates.
On this photograph the tip of the hammer rests on the boundary clay layer.
Francois Gohier

© Francois Gohier / ardea.com

FG-CB-532

FG-CB-532
Dinosaurs - Ceratopsians - Horned dinosaurs.
Photographed at the Royal Tyrrell Museum of Paleontology, Drumheller, Alberta, Canada
Arrhinoceratops brachyops
Cretaceous, Alberta, Canada. The small hole on the left side of the frill (right on the photo) was most likely punctured by the horn of another horned dinosaur - probably of the same species - during a confrontqation.
Francois Gohier

© Francois Gohier / ardea.com