Brachiopoda Composita, TimsRockShop.com

Brachiopoda Composita is an extinct clam from the Permian Period, about 250 million years ago. I remember collecting these more than 40 years ago in an area North of the Grand Canyon. They occur in the Kaibab Limestone formation which forms the top layer at the Grand Canyon as well as much of the Colorado Plateau that covers most of northern Arizona. These have a notably reddish color, whereas specimens that you might find at the "Canyon" are the cream color of the typical Kaibab limestone. Note: it is illegal to collect at the Grand Canyon, so if you are there, its "view only"!