VISIT THE TRIASSIC

A fossil hunter slowly builds the record of a forgotten age in what is now the Petrified Forest. Throughout this area, he has written, "sluggish streams flowed between low hills on their way to the sea..."

THE TRIASSIC

The Triassic sounds as if it might be the third vertebra below the scapulae. Or maybe the third stage of a booster rocket. What it really is, though, is a geologic period in the earth's past, from 225 to 190 million years ago, tucked between the Permian and Jurassic.

At Petrified Forest National Park, paleontologists rebuild this ancient time so that we all can visit the Triassic Period.

Dr. Sidney Ash, professor of geology at Weber State College in Ogden, Utah, has visited the Triassic in the Petrified Forest nearly every year for the past quartercentury. A paleobotanist, one who studies fossil plants, Sid Ash, called "the grand old man of the park," is credited with having studied its rock layers more thoroughly than any other paleontologist.

The source of this estimate of Ash's work is Robert Long, research associate at the University of California at Berkeley and National Park Service paleontologist at the Petrified Forest. Long recently led the team of sunburned scientists that uncovered the world's oldest articulated dinosaur in a gully below Chinde Point. (See page 4.) According to Long, it was Ash who set the stage for this discovery by re-creating an accurate picture of the environment of 225 million years ago, when dinosaurs first appeared on earth.

At that time, most of the earth's land was jammed together in one supercontinent called Pangaea. Eventually, Pangaea broke apart and the continents separated, floating on plates of the earth's crust atop a viscous mantle under the surface. Before the breakup, Arizona was much deeper into the Sun Belt-about 1700 miles farther south, where the mouth of the Amazon River is today.

This ancient tropical Arizona climate was much warmer and wetter. Where there is no permanent water today, Triassic streams and rivers meandered northwest past swamps and marshes, ponds and oxbow lakes. Their water dropped silt eroded from the Mogollon highland of northeastern Arizona and western New Mexico. Volcanoes added layers of ash.With densely growing vegetation and few hills, the environment was more reminiscent of Everglades National Park than today's Petrified Forest. The dominant trees were 200 feet tall, relatives of modern Norfolk Island pines. Most of these decayed when they died and nourished other plants. But some, an unusually large number, collected in backwaters and lagoons, where they rapidly were covered by silt. Cut off from oxygen, they were immune to decomposition carried out by decay organisms. Eventually, groundwater percolating through sand picked up silica minerals and deposited them as quartz within the cell spaces and cavities of the dead trees. Thus, over long ages, the trees eventually were converted to stone replicas of the original living plants.

Millions of years of erosion of distant mountains piled layer upon layer of silt on these lowland tree tombs. The colorful system of layers containing the trees eventually developed into rock called the Chinle Formation. It is widespread across the Southwest, but only in northeastern Arizona does the Chinle contain such abundant amounts of petrified wood. Some sixty million years ago, the pressure of continental plates grinding together and overriding each other caused northern Arizona to rise at least a mile. As soon as the uplift began, water and gravity commenced to tear the land down, eventually stripping away the layers above the Chinle. This erosion now is uncovering long-buried petrified wood, a process particularly obvious at Blue Mesa, within the national park.

Sid Ash, however, does not concentrate on petrified wood. Instead, he diligently prospects for leaves and stems, even pollen grains, far less likely to be preserved and far less common than petrified wood. Analysis of these tiny fossils teaches much more about the Triassic than do the giant stone logs.

THE TRIASSIC

It is a fascinating revelation that many of the fossils Dr. Ash craves are not mineral replacement of organic matter or impressions of the leaves. Rather, he finds parts of the actual plants themselves, the original organic material, more than 200 million years old. Compressed beneath 3000 feet of sediment that now has washed away, the tough cuticle of leaves and stems often remains unaltered over unimaginable lengths of time and can be examined under a microscope.

Through examination of these minute fossils, about 160 different species of Triassic plants have been distinguishedmore than from any other location of the same age in the world. Dr. Ash seems to discover additional species almost every time he takes to the field in the Petrified Forest. Each addition to his plant inventory reveals a little more about the environment of that time. It was a very lush world, a green and brown world, before the evolution of flowering plants. Insects ate fern leaves and bored holes in tree trunks, as the fossil record now reveals. Heavy-scaled fish inhabited the waters, hunted by alligator-like phytosaurs, some more than thirty feet long, each phytosaur a ton of hungry terror. Another fish eater was a Metopo-saurus, one of the largest amphibians of all time. Actually visiting the Triassic would be highly hazardous because of the presence of that period's largest land living carnivorous reptile, Lythrodynastes, a twenty-foot predator with a head similar to that of the more recent and famous Tyrannosaurus. Lythrodynastes ran on two legs with its head thrust forward, a posture like that of thecodonts, pre-dinosaur reptiles whose fossils also are found at Petrified Forest, which included reptiles more primitive than the dino-saurs. The oldest dinosaur ever collected in the Petrified Forest may have been a relatively small ancestor reminiscent of the famous brontosaur, largest creature ever to walk the land. Perhaps most signif-icant, though, was the rhinoceros-size rep-tile calleD Placerias, which belongs to therapsids-mammal-like reptiles.

More prosaic were crayfish similar to modern crayfish.

The existence of crayfish was estab-lished by Dave Porter, a novice fossil hun-ter from England, who accompanied Sid Ash on one of his prospecting tramps down a gully eroded amid banded buttes of the national park. Dr. Ash was explain-ing the Triassic environment, the nature of the fossils, and how and where they are found. The Englishman used a geologist's rock hammer to knock away a few layers of shale and came up with a perfect cray-fish. In five minutes, Porter had stumbled on an astonishing discovery that had eluded the expert for decades.

Luck, of course, sometimes plays as great a role in discovery as does persistence, skill, and knowledge. Hard labor also is a major component of the task Sid Ash has set for himself. With hammer and canteen, he roams the hot, dusty gulches of the park. Whim and intuition tempered by experience inspire him to climb steep, crumbling banks to gray layers of shale where fossils might be excavated. He does not bother with the red and purple layers, which have been oxidized, destroying any fossils once contained.

Sometimes he hits pay dirt, maybe the edge of an ancient pond where leaf litter accumulated to be buried by silt and sealed off from oxygen before rotting. Here he may find whole fern leaves, each detail down to the tiny reproductive organs perfectly preserved. Elsewhere he may find only scant black and rust bits of Triassic leaves that he has seen literally thousands of times.

Ash explains that he keeps coming back to hunt fossils because his anticipation is like that of "a kid opening Christmas presents.

The Case of the Wandering Wood

Petrified Forest National Park was set aside to preserve the world's largest collection of petrified wood at a time when gem hunters were dynamiting large trunks on the chance of finding valuable crystals that had formed naturally in the cavities of the former trees. President Theodore Roosevelt created a national monument in this area in 1906, making it illegal to remove even the tiniest sliver of petrified wood or any other fossil, archeological relic, or living plant. Yet illegal removal of estimated tons of petrified wood by park visitors continues annually despite the watchful eyes of the National Park Service. Some of these looters of their children's and nation's heritage become conscience stricken. They or members of their families return the purloined souvenirs by mail. Some of the letters of apology that have accompanied these pieces of petrified wood are displayed (with the signatures blocked out) in the Rainbow Forest Museum within the park. Ranging from hilarious to deeply philosophical, they constitute one of the most memorable displays found within any national park. Children have written the best letters. Park Service education of the public, Though, is reducing removal of fossils. When Sid Ash undertakes his specially permitted collecting of plant fossils to enlarge our understanding of the Triassic Period, he usually does so away from park roads. If park visitors see him digging in shaley clay and ancient volcanic ash and do not understand what he is doing, they are likely to send park rangers tearing out to prevent theft. At times, it is a mildly embarrassing hassle for Dr. Ash and for the Park Service. But both are abundantly grateful for increased public concern.

AMATEUR PHOTOGRAPHY CONTEST

Arizona Highways will conduct its first amateur photography competition this summer. Prizes will be offered, and the winning photographs will be published in the magazine in the spring of 1987. Here are the contest guidelines:

Outdoors in Arizona A Guide to Camping

Whether you're looking for a place to pitch a tent or a spot to park a recreational vehicle, we have the guide to take you there. Arizona Highways and outdoor writer Bob Hirsch bring you Outdoors in Arizona: A Guide to Camping. In this 128-page book, you'll discover each camping site's location, size, and terrain; learn whether it is equipped with water, facilities, and a supply store; and determine whether there are fees, vehicle restrictions, and seasonal limitations. You'll also find more than 80 full-color photographs, a selection of recipes for outdoor cooking, and a dozen maps to guide you on your outdoor adventures. Plus, there are 10 campfire stories by Marshall Trimble, each skillfully illustrated by cowboy artist Joe Beeler. It's the ideal guide for an avid camper or anyone who enjoys seeing and reading about Arizona's great outdoors. Only $12.95, softcover (includes postage and handling). As an added bonus, we'll include with your purchase an Arizona road map to accompany you on your travels. Text continued from page 39

"It's a hot, dirty business," he admits. "And often it takes a long time to get anything." But he is fascinated by building a picture of the Triassic, "working at it like a detective."

Actually, this professor resembles a detective less than he resembles a desert prospector who has spent his life searching for gold or silver. Dr. Ash's jeans are worn thin at the knees from kneeling on rocky ground while hammering away for fossils. Desert sun has burned the back of his neck to the color of his battered boots. Perhaps most important, he has the mind-set of a prospector: the next big find may come with the next swing, the next cloud of dust coating his face, the next layer of shale pried apart.

His is a rugged study, but Sid Ash is pleased with his exploration of the Triassic landscape. He hopes to expand the list of 160 some Triassic plants to 200. From a distance of 200 million years, a catalog of 200 species would be extraordinary.

Many more types of plants exist today than were growing in the Triassic. Great variety began with the development of flowers some 120 million years ago, still well within the age of dinosaurs, but long after the first one roamed the vicinity of Chinde Point. In a relatively short time, geologically speaking, flowers have diver-sified to more than a half-million species worldwide, some 5000 in the Rocky Mountain chain. This remarkable variety has come about because flowers increase the efficiency of pollination and seed production. This, in turn, creates many more opportunities for flowering plants to adapt to different types of growing situations within a particular environ-ment, causing plants to evolve into var-ious species.

Even in the harsh environments of dry, short grassland, shrubland, and desert of northeastern Arizona, plant variety in-cludes not only a colorful abundance of wildflower species, but also many plants with inconspicuous flowers, such as grasses, sages, other shrubs, and decidu-ous trees. In addition there are a few non-flowering plants that continue to repro-duce quite successfully in a manner simi-lar to that of Triassic plants. These include pines, junipers, and even horsetails that grew with twelve-inch-thick stems during the Triassic.

Sid Ash's picture of the Triassic grows more complete each year. Comparison of that time with the present demonstrates that the evolution of flowers was an essentially unnecessary development. The masses of Triassic plants that supported a large animal population are convincing evidence that flowers are not a require-ment of abundant life.

In the very different environment of New England, poet Ralph Waldo Emerson was asked what use there was for a lovely flower to grow in a bog where hardly anyone ever got to enjoy its beauty. Emerson was inspired to respond with one of American literature's finest poems, "The Rhodora," which includes these lines: if eyes were made for seeing, Then beauty is its own excuse for being. Why thou wert there, O rival of the rose! I never thought to ask, I never knew. But in my simple ignorance suppose The self-same Power that brought me there brought you.

One day Sid Ash may find the world's oldest flower in the Petrified Forest, just as Rob Long's crew found what may be the oldest articulated dinosaur and may have found a reptile predecessor of mammals. In any case, we mammals called humans were produced by the same force that produced flowers. We recognize beauty, and even strive to create it our-selves. Why should the impulse to create beauty after the necessities of survival are assured be limited to that tiny part of life we call human? While it is obviously true that flowers exist to produce seeds, it seems equally self-evident that seeds exist to produce flowers.

Sid Ash tramps through the heat, scrambles up loose rock, tolerates biting insects, broils in the sun, and breathes the dust kicked up by his repeated hammer blows, then daily catalogs the fossils he drags home. All this fills in our picture of the Triassic. The lush world he guides us through seems extremely fertile, comfortable, even relaxing, compared to the austere national park of stone trees. But the Triassic is all prosaic, hard-working green without the glorious jewels of Crystal Forest, the color of Rainbow Forest, or the stark erosional sculpture of The Tepees of Blue Mesa. Most of all, it lacks the even more vivid hues and variety of flowers. We benefit from an ever more complete view of the Triassic because it gives us an invaluable perspective on the world we live in today. We are inspired by what appears to be progress on this earth. The scene today, despite its austerity, is more varied, more interesting, more beautiful than the scene 225 million years ago. Through third-hand experiencing of the Triassic, we reap new joy of thankfulness for the glories of our own time. Yes, the Triassic is a nice place to visit, but we can be glad to live here.