For bid is a nice ichnofossil specimen containing a reptile trackway on Coconino Sandstone from the Colorado Plateau region of Northern Arizona. The specimen dates from the Early Permian Period of the Upper Paleozoic Era, and is approximately 280 million years old. The plate is the raised, or natural cast portion of the prints and measures approximately 12 inches long by 6 inches wide and 1/2 of an inch thick.

This piece features a nice reptile trackway with lots of great toe and claw detail. The prints measure on average to be about an inch wide and are probably from Cheilichnus duncani , an early mammal-like reptile. These early Permian creatures walked with their legs directly below their bodies rather than splayed out to their sides like most reptiles. This caused their bodies to be located higher above the ground, seldom leaving marks from a dragging tail. It was once believed that these Permian tracks in Coconino Sandstone were made by amphibian creatures. Research has shown however, that these tracks were formed in a great dune environment that once covered most of what is now Northern Arizona and the Grand Canyon area.

Please links with articles on Coconino ichno's, that also describe these type of Permian tracks:

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