Several types of fishes, amphibians, and small reptiles probably lived along the streams and in the quiet pools of those ancient marshes. Among them were lung-fishes whose teeth or “dental plates” are now found scattered through the badlands of the Petrified Forest.
Large rushes, or horsetails, bordered the streams and matted the swamps. Their hollow stems grew to eight and ten inches in diameter and 30 to 40 feet tall. At each joint were whorls of slender branches. Large, broad-leaved ferns formed a striking contrast with the delicate foliage of the seed fern types. Club mosses probably grew in small clusters in sheltered places along the banks of the streams and pools.
How different this scene of millions of years ago was from our present-day landscape and modern plant and animal life. The climate must have been at least sub-tropical then; today it is semi-arid.
In contrast to the plants and animals of those Triassic times living in swamps and marshes, we now have plants and animals that are able to exist with a minimum of moisture. The present ground-cover is seldom over three or four feet high, but includes a wide variety of plants ranging from very small flowering herbs to the several species of gray-foliaged salt brush and other shrubs. With suitable moisture, the spring and fall wildflower displays are often very showy. The early blooms of the chimaya, phacelia, and the large, white, evening primroses are soon followed by desert mallow; vetch; a small white daisy-like Fleabane; the large yellow tulip-like flowers of the mariposa or sego lily; and as the season advances, the paint brush; asters; snake weed; golden aster; rabbit brush; and many others.
In contrast to the sluggish reptiles and amphibians in the Triassic, we now have the fleet pronghorn (American Antelope); occasional coyotes and bobcats, porcupine, prairie dogs, rabbits, and many of the smaller rodents. Several species of harmless snakes and an occasional rattlesnake; slender, striped, long-tailed race runner lizards; scaled lizards, and the bright, green-backed, yellow-footed Bailey Collared Lizard which frequently brings visitors hurrying in to inquire if it is poisonous. It isn’t!
Several species of birds such as the Desert Horned Larks and rock wrens make this their permanent home while many other species ranging in size from the tiny Allan Hummingbird to the mighty golden eagle either stay here during various parts of the year, or pass through in the spring and fall migrations.
Intermixed with the surface deposits of petrified wood and other remnants of the ancient Triassic time are the much more recent remains of early men. Ruins of their homes, fragments of their handiwork, and examples of their arts are to be found in many locations.
These people were pre-Columbian Pueblo Indians, ancestors of our modern Pueblo Indians, and of the same type that inhabited the other pueblo and cliff-dwelling sites in the Southwest. It is probable that there was considerable trading carried on between the people of this area and those at other locations, since many of the same pottery types are found throughout.
This somewhat desolate region was apparently fairly densely populated by little groups of farming Indians. With no survey or study of the monument area having been made, more than 300 ruin sites have been located and there are many others nearby. These ruins of stone buildings are usually from one to a few rooms in size. However, one ruin near the Puerco River Ranger Station is estimated to have had about 125 or more rooms. It is built in the form of a hollow square about 180 feet by 230 feet, around a plaza about 130 by 185 feet. Probably two stories in height, it could have housed nearly a hundred families.
A study of the pottery fragments from each site helps us to tell the approximate time that the particular site was occupied. This time varies from about 500 or 600 A.D. to 1400 A.D., some being used over a longer period than others.