WILDLIFE THROUGH ARIZONA'S AGES

Arizona is known around the world for ancient trees whose agatized logs make up the Petrified Forest. With an age of a hundred million years, those logs seem incredibly ancient when we compare them with human history. Yet they appear late in the story of life that is told by fossils from Arizona's rocks. That story begins almost 800 million years ago, in an age which some geologists call the Belt and others, the Algonkian. At that time the state was largely marine, a gulf or sea that spread northward and eastward from the Pacific. It filled a basin that kept on sinking till salt water invaded Utah.

Ancient seas are traced in rocks made of sediments worn from nearby lands and deposited under water. During Belt times these materials ranged from pebbles and mud to limy ooze that settled layer by layer and stratum by stratum until they reached a thickness of two and a quarter miles. They can be seen in many parts of the Grand Canyon, but show best north of Desert View.

Sandy bottoms of this early sea were barren and so, perhaps, were those made of mud. But when limy ooze accumulated it was often overgrown by plants. Not trees, for they cannot live under water-and, besides, trees had not come into existence 750 million years ago. Plants of the Belt Age were seaweeds and other simple algae that covered themselves with walls and layers of limy material. Thus they produced domelike and biscuit-shaped masses that became solid and stony even while the plants were alive.

Stony algae are common in very old rocks, but fossil animals are rare. Those of Belt age include some simple shells, a few sand-filled burrows made by worms, and one lump of hardened mud replacing a jellyfish. Only the last comes from Arizona, where it was found in the Grand Canyon nineteen years ago.

Belt times came to an end amid changes so widespread and so great that we call them a geologic revolution. Deep oceans probably stayed where they were, but seas (which were shallow) disappeared as their basins turned into land. In the West, there first was generaluplift; then the raised sea bottoms broke into blocks that tilted and rose into mountain ranges separated by elongate valleys. They must have looked like the ranges and valleys that now cover most of Nevada.

Mountains sometimes seem to last forever, but they really are temporary. The very fact that great masses of rock are built up into highlands means that frost, rain, and running water must begin to wear them away. Today's mountains become lower and lower; those of past ages have been reduced to lowlands or to rounded hills. We see both far down in the Grand Canyon, with only breaks (called “faults”) and tilted strata to show that they once were peaks.

Two things can happen to worn-down country; it may be pushed up again or may sink. If it sinks very far it becomes the basin of another sea.

That is what happened in Arizona some 550 million years ago. Waves beat against hills that were turned into islands; shoals were covered with sand into which worms burrowed. Later, as the bottom grew muddy, worms gave way to creatures called brachiopods, whose wrinkled shells were borne upon tough stalks that extended into the mud. Cone-shaped snails swam in schools by flipping finlike structures that really were modified feet. Tiny bivalved crustaceans also swam, but early relatives of crinoids, or sea lilies, grew upon jointed stems. Trilobites crawled or swam with feathery legs; when hungry they grubbed into mud to capture worms. The trilobite's jointed body was covered with horny armor. Two glowing compound eyes looked upward: jointed feelers smelled and touched things resting on the bottom.

The sea in which these creatures lived was the first of many that flooded the West during the Paleozoic Era. We sometimes call it the Age of Invertebrates, or animals without backbones. Actually, bones of several types developed early and proved themselves better than shells for creatures that had to move freely. At least 300 million years ago, fish swam over coral banks where Bisbee and Flagstaff now stand or grubbed for food in streams whose silt-filled channels are now exposed in cliffs of the Grand Canyon. Many of these fish had little or no bone inside their bodies but were partly covered by bony armor.

The revolution that closed the Paleozoic Era extended through two geologic periods. Sometimes it allowed seas to spread widely; coal-age rocks of Arizona contain sea shells, and so does a later limestone exposed at the river of the Grand Canyon and as far to the east as Meteor Crater. Lowlands are recorded by beds of sandstone and shale that contain remains of ferns and small trees, tracks of amphibians and reptiles, and impressions of insect wings four Inches wide. The insects themselves resembled dragonflies.

The next era in life's story was the Mesozoic, often called the Age of Reptiles. It began some 300 million years ago, and its first division (termed the Triassic) may be traced in sandstones and shales that appear near the New Mexican border and wind westward into Utah. They may be seen in Echo and Vermilion Cliffs, as well as the multicolored badlands of the Painted Desert.

Fossils are few and poor in the older Triassic sand stones, but those of the Chinle shales are both plentiful and well preserved. They tell of warm-even subtropical lowlands across which rivers wandered to still another sea. During dry seasons those rivers became shallow and flowed slowly; after long, hard rains they rose in floods that covered the ground with water which left layers of mud when it drained away or evaporated. At other times small volcanoes erupted streams of molten lava and thick clouds of volcanic ash. Beds of dark, greenish lava may be seen from the Painted Desert Inn, while deposits of ash form layers in many buttes of the Petrified Forest Lowlands must have been covered with ferns and other small plants, but the commonest Chinle fossils are trees. They range from small cycads resembling sago "palms" to araucarians, or monkey-puzzle pines, whose trunks were as much as ten feet thick and two-hundred feet high. The stumps of some stand where they grew, with their roots in dark shale that once was soil. Other trees must have come from distant forests, where they fell or were washed into rivers at flood stage and were carried downstream. Some logs doubtless drifted out to the sea, but many more were stranded on sand bars or mud banks. Steps to the top of one butte in the Petrified Forest let visitors go there to view the tangle of driftwood lodged on one of those banks. Streams, ponds and swamps made homes for aquatic animals. The most plentiful were fresh water mussels, whose fossils occur in such abundance that they almost cover some buttes. Armored fish must have been plentiful, too, for their thick bony scales fill beds of shale that extend for miles along cliffs in southern Utah. Some of those fish were savage predators like modern garpikes, to which they were related. Others had blunt, peglike teeth fit only for crushing shells. Fish of the latter type evidently fed on mussels.

Ceratodus, which ate whatever it could get, was related to the lungfish of present-day Australia. This creature inhabits small ponds whose waters are robbed of oxygen by decaying plants during the dry season. Trout or bass would smother in such surroundings, but the lungfish merely comes to the surface and gulps air into a lung that is a remodeled swim bladder. Triassic lungfish must have done this, too. Their fossils are evidence that ponds regularly became stagnant during those times. Fish preyed upon each other and were eaten by amphibians that reached lengths of five to about eight feet. They were broad-bodied, short-legged giants with flattened heads; when hunting they crept on the bottom or sculled with their powerful tails. Between meals they lay in sheltered places, slowly digesting their food.

Phytosaurs ("plant reptiles") got their name because an early professor thought they were herbivores. They really were meat eaters as much as twenty feet long that resembled crocodiles. Phytosaurs could walk clumsily or swim with great speed, they also could lie hour after hour with only their nostrils above water. Those nostrils opened above and between the eyes-never on the snout, like the nostrils of crocodiles, Pseudosuchians ("false crocodiles") resembled their namesakes only from neck to tail. Their heads were small and weak; their blunt teeth were good only for eating plants; their bodies were covered by bony plates bearing a row of spines along each side and horns upon the neck and shoulders. False crocodiles probably spent most of their time on mud banks and in marshes too shallow to attract big, savage phytosaurs.

Protosuchus ("first crocodile") was discovered in orange-brown beds that lie above the Chiale shales. Protosuchus was about thirty inches long, with a broad head, large eyes, and a tail of moderate length. Back, belly and sides were covered with armor, and the jaws contained short but sharp teeth. Hind legs were longer than fore-legs, a feature which shows that Protosuchus was related to dinosaurs.

The word dinosaur ("terrible reptile") suggests large meat eaters and small larger herbivores. But dinosaurs of Chiole times had not had time to evolve into giants. They were trim and primitive bipeds about eight feet long, with narrow heads, slim necks, and long tails. They spent most of their lives on open uplands, where they walked and ran with tails held out stiffly to balance their bobbing bodies. The weight of full-grown specimens ranged from forty to sixty pounds.

Larger dinosaurs reached Arizona a few million years later, for their remains have been found near Tuba City. But big reptiles required lush habitats, and were driven out as moist lowlands turned into deserts extending from southwestern Colorado to Nevada. Winds howled across the arid uplands, piling sand into dunes that now appear in the Echo and Vermilion Cliffs, Zion Canyon, and Rainbow Bridge.

Shifting lands and seas of the next fifty-five million years also were less than hospitable to large and hungry reptiles. Many marine deposits are full of oysters and other seashells, while formations that settled in swamps contain coal, fossil wood, or leaves of fig trees, walnuts, willows and redwoods. But dinosaurs are almost un-known, though their remains have been found from New Mexico to northwestern Canada.

The Age of Reptiles gave way to the Cenozoic Era, during which warm-blooded, hairy beasts-the mammals -became dominant. At first they were primitive and crude; in twenty million years years they barely began to resemble modern types. Like dinosaurs, they left few records of their progress in Arizona, where erosion destroyed all formations and few new ones were deposited. Not until the Ice Age did rocks and fossils resume the story of life in Arizona.

The term Ice Age is deceptive, for it suggests a million years of winter, followed by sudden warming as ice sheets melted away. That picture, however, is too simple and much too rigorous. Throughout much of North America and Europe there were four principal glacial advances, and a minor fifth. Between them came intervals of warmth, when climates sometimes became milder than they are today. Even when ice sheets spread their utmost, they stopped short of the Mason-Dixon Line in the East and left the Southwest almost untouched. Mountain glaciers did cap the San Francisco Peaks, and most of Arizona and adjacent states provided better homes and more food for wildlife than they do today.

This hospitality was accepted by a great variety of mammals. They included many creatures still found in Arizona: jack rabbits, prairie dogs, coyotes, badgers, and peccaries, or javelinas. Other creatures, however, have long been extinct. Among these were wild horses as large as modern "cow ponies," as well as bison with enormous humps and horns measuring three feet from tip to tip. The horses sometimes grazed near herds of camels that stood seven to eight feet high and were about as large as modern dromedaries: Since these animals seem to have been related to llamas, we infer that they had no humps.

True llamas evolved in South America, where the wild variety is called guanaco. At least one kind of guanaco reached Arizona during the Ice Age, and so did several other emigrants from South America. One of these was the tapir, a long-snouted herbivore whose modern relatives like to wallow in water. Ground sloths apparently preferred tree-dotted uplands, where they lumbered about awkwardly on feet equipped with enormous claws. Some species became very large, but one that browsed on low trees in southern Arizona stood almost four feet high at the hips and was more than eight feet long. It was covered with coarse yellowish brown hair. Hair and skin, as well as bones and dung, have been found in caves which the sloth used for dens..

Glyptodonts were the most bizarre of South American emigrants. They sometimes are called giant armadillos, but the bony armor that covered their bodies was solid, with no trace of movable joints. The top of the head was armored, too, and the tail was encased in knobby bones.

At least two kinds of elephants, or mammoths, lived în ancient Arizona. Both were huge beasts ton to thirteen for high, with long tusks. Early men apparently killed these monsterns and ate their flesh. Those that died natural deaths were devoured by large, heavy-jawed wolves whose bones have been found in surroundings which show that the beasts were fond of carrion. Lion-like beasts probably were active hanters, and were very powerful. Males grew to be at least one fourth larger than male ions of modern Africa, and were more than three times as heavy as our mountain lion.

Lions, elephants and camels suggest a world far removed from present-day Arizona, Actually, there beases of the Ice Age Age survived long after man settled in the Southwest. Cochise wibesmen ate elephant and camel mest wear the site of présent-day Douglas; Ventens hunters carried haunches of tapir, wild home, and ground sloth home to their cave in the Castle Mountains. Since Ventana henters lived little more than toyooo years ago, they brought the story of ancient life to the threshold of modera cimes.

THE BLUE HORSE:

For those who wondered why Adee's Blue Stallion was blue (October, 1959 issue), the following poem by Alice Benton will be of interest.

Legend: The Indian artist was painting what looked like a blue horse, and the white man, looking over bis shoulder, said, "Why do you make the horse blue? There isn't such a thing." The Indian replied, "But this is not a borse. It is the spirit of thunder."

Thundering, thundering over the mountains, Blue coat the tone of blue heavens afar, White feathered fetlocks streaming rain-fountains, Lightning bolts flashing as hoofs strike a starRiderless steed, you are king of the thunder, King of the storm and the fierce winds that blow From your quivering nostrils. You are the wonderBorn in the hearts of the earthlings below.

Susan Randall Bismarck, North Dakota

HANDS ACROSS THE SEA:

... In the hope that you might find the following anecdote of interest I am writing this letter to you. In August of 1954 I began to collect authentically dressed foreign dolls by writing to heads of state in all parts of the world asking if they would exchange a good-will pair for whatever they might care to have me send from California in return. I explained that the dolls were to be used as a free educational display in schools, before youth groups, service organizations, etc. as a means of building better understanding and as a small step towards developing a climate of peaceful coexistence between all peoples. My letter to Australia was turned over to an anthropologist in the museum in Sydney who offered to make aborigine dolls in exchange for Hopi Kachinas, which he had read about in ARIZONA HIGHWAYS. This wasmy introduction to your magazine. Immedi-ately I wrote to the kachina maker, Abbot Sakiestawa, in Winslow and now his kachinas are part of the Australian Museum's display. Recently I learned that Andre Malraux, Minister of State in charge of Cultural Affairs, in the cabinet of President De Gaulle, is an avid kachina collector and a copy of your July issue has been sent to him. Would it be too trite to say "it's a small world"?

For the records, there are more than 600 dolls now from 147 different nations and territories and they have been seen by tens of thousands of children and adults in the metropolitan Los Angeles area, at no charge. For the U.S.A. I have about 25 different Indian tribes but no Papago, Pima, or Yuman tribes. Do you know where dolls from these peoples could be found?

Ethel Averbach Van Nuys, California

All the teachers in the school use pictures from your magazine to decorate their rooms. We keep them for years and years and if we are feeling very generous, we sometimes let someone else borrow a few. After a while they get pretty dog-eared, but we trim the edges, put them on a new mount and back on the bulletin board they go. Maybe this isn't so good, though. Our children will grow up thinking the whole world looks like ARIZONA HIGHWAYS.

Mrs. Joan St. John Thermal, California

MISSED

Tonight, After the big Moon-silvered plane had gone, There was a lonesome place left in The sky.

ADELAIDE COKER

ARE THERE MIRAGES

Tell me again, do the desert winds blow Over arroyos that I used to know? Still are the cactus flowers brilliant in spring In barren places? My memories bring Visions of sunsets that drip molten gold Over blue mountains centuries old, Fading to distance beneath pale moonbeams.

Are there mirages still promising dreams?

GRACE BARKER WILSON

THUNDER-CAT

My kitten thinks thunder must be A giant cat that growls Behind low black clouds menacingly, As stealthily it prowls; And so, to prove he does not lack A gallant heart, he growls right back.

ALICE M. SWAIN

TRAINS-THEN AND NOW

Over the silvery rails of morning, Winding her way through scrub-oak and brier, Sounding her whistling, whistling warning, The little train came, smokestack and fire; Thunder and steam and a bright cowcatcher, No horse could pass, and no rig match her.

Today, with a voice like a great moose calling, The streamliner bullies along the run, Up through the canyon he comes a-bawling, And my heart laments as this arrogant one Charges through greasewood, cholla and thistle, With never a smokestack or a whistle, Oh never a whistling whistle.

-ELSIE MCKINNON STRACHAN

NIGHTS

Spring night is a new born calf, Wet, warm, and hungry for the world.

Summer night asks for silence Heavy enough to hold a star.

Autumn night with the swiftness of a witch's broom Steals across the world and enshrouds it In Jacob's coat of many colors.

Winter night, an old beggar woman Wrapped in meager clothing, Yearns for dawn and warmth.

-SUE CHRISTNER

OPPOSITE PAGE

"RUBY, ARIZONA," BY JOSEF MUENCH. 4x5 Linhof camera; Ektachrome; f.32 at 1/5th sec.; 5" Schneider Xenar lens; April; sunny day. In the Ruby Mountains of Santa Cruz County is the old mining camp of Ruby. A spring carpet of poppies adds color to the scene. When spring rains have been generous, this area is particularly rich in spring flowers and generally the display is at its best early in Arizona.

BACK COVER

"JOSHUA TREE SILHOUETTE" BY EARL E. PETROFF. 4x5 Graphic View camera; E Ektachrome; f.32 at 15 seconds; 203mm 7.7 Kodak Ektar lens; March, 1957; sunset; 64 Norwood Meter slide out. Under-exposed 1 stop; ASA rating 10. This Joshua tree was photographed off Highway 93 midway between Congress Junction and Wikieup, roughly some 115 miles from Phoenix. These trees bloom in late February and early March depending on rainfall and weather conditions. The photographer says: "This is a combined photograph. I wasn't able to be in the forest for a sunset, therefore I photographed the Joshua Tree silhouette on super film. I then made a copy of this negative on Kodalith thin base film. This film developed in Dektol produced a high contrast mask which was slipped over a sheet of color film in the holder and exposed for the sunset.