But the neat thing about the Triassic is not the little dinosaurs. They had not really reached their dominance of the terrestrial ecosystem at this point in time. There were other creatures, some of them absolutely terrifying...like the phytosaurs.
There are lots of other creatures found in the sediments of the Chinle. The odd looking creature below is a Placerias hesternus, one of the therapsid reptiles, sometimes called the mammal-like reptiles. Huh? Since when is a reptile anything like a reptile? Well...when they have a more upright stance than reptiles, when they have differentiated teeth including fangs, and when they may even have been endothermic, i.e. warm-blooded. The therapsids were in fact the ancestors to the mammals, who appeared in latest Triassic time (they then presumably provided the dinosaurs with protein for the next 100 million years before an asteroid wiped out the reptilian overlords).
All told, the park is one of the richest Triassic fossil beds in world, with 200 kinds of plants, and dozens of therapsids, phytosaurs, amphibians, and early dinosaurs. But wait (as they say in late-night TV ads), there's more!
Most of the fossilized trees were carried from forests in surrounding highlands during floods. They were buried and the wood decayed away but was replaced by silica (quartz, in the form of agate and chalcedony). The wood is strikingly colorful; a lot of petrified wood from elsewhere occurs in pretty plain colors, but here there is a veritable rainbow in practically every sample. Entire trees, 100 feet long or more, are common in many parts of the park.
Petrified Forest is another place that suffered a lot of abuse before it became part of the national park system. Train passengers in the late 1800s stopped at the nearby station and walked off with tons of rock. A company once proposed to grind up the petrified wood to be used as an abrasive. Local citizens sought park protection as early as 1895, but it was 1906 before Teddy Roosevelt designated the site as a national monument. It became a national park in 1962.
|Photo by Mrs. Geotripper|
Here is the explanation of my "abandonment" theme for this series: http://geotripper.blogspot.com/2012/06/abandoned-landsa-journey-through.html