The wind blew.
The planet spun.
The light faded
And all the while I stood pondering fate on a ridge above the crystallized corpse of a lost world on a ridge in the Petrified National Forest. I patted Lobo’s furry head and we shared a mammalian moment, having journeyed together back to where it all started.
Lobo cocked his toothy head, thinking his wolfish, warm-blooded thoughts. Perhaps as felt frail as I, staring out across the fissured purple hills of Blue Mesa. Most likely he was just watching the raven, playing on the wind. He’s still in touch with his wolfish ancestors, who show up in the fossil record 40 million years ago – long before our ancestors stood upright. Ravens and wolves evolved together. Even now, ravens will lead wolf packs to their prey – confident of the scraps of the kill. So Lobo pays more attention to ravens than even to the smell of carrion.
I savored the view – a wasteland where once a tropical forest rustled. The swelling and shrinking of the bentonite clays in the lurid, 800-foot-tick Chinle Formation prevents roots from gaining purchase. That clay is the gift of the volcanoes whose ash smothered this world. But there’s not much for Lobo to sniff now — just dust and death and ravens on the wing. Lobo lives in blissful ignorance of mass extinctions and fate for he lives ever in the moment. I envy him.
We’re both survivors, Lobo and I, for our shared ancestors evaded the mass-extinction that snuffed out this world 200 million years ago.
The seven types of 225-million-year-old trees that have crystallized into these giant logs have all gone extinct, along with most of the 200 types of plants fossilized here. Gone also are the ancestors of crocodiles, mammals, amphibians and dinosaurs as well as world-dominating lines that left no descendents.
Most of the experts blame the mass extinction that snuffed out 75 percent of the world’s species on a frenzy of volcanism. The Petrified Forest then lay in the middle of the supercontinent Pangea, straddling the equator. Some shift in the earth’s core or mantle caused a great fury of volcanic activity. A rift broke up the supercontinent by opening up the Atlantic Ocean , which moved North America to its current position on a conveyor belt of crust.
The still inexplicable events killed off the 200-foot tall trees of the not-yet-petrified forest – and all those dwelling in its shade and swamps. Here stalked the 10-foot-long Temnospondyls – monster salamanders with giant, flat heads. Here lurked 30-foot-long, phytosaurs. Here munched the peaceable armored aetosaurs, whose line died out utterly. Here hunted the once-confident rauisuchians, all doomed to extinction. Here also scurried the humble ancestors of the dinosaurs, cat and chicken-sized creatures fated to inherit the world.
Here wandered also the “mammal-like reptiles” who once dominated, nearly died out in an even more encompassing extinction event 250 million years ago, recovered, grew huge then suffered in mass extinction that ended the Triassic. The giants among the mammal-like reptiles succumbed to the scorching skies. The little ones hid themselves away. Those few survivors eventually gave rise to Lobo – and me.
The cataclysm cleared the way for the dinosaurs to rule the world for the next 150 million years. We little, warm-blooded ones huddled in their shadow. Then some 65 million years ago, an asteroid struck, blotting out the sun and killing everything once again – starting with the lordly dinosaurs.
Well, not everything. We mammals still cowered in the shadows – in cracks and burrows, warm blooded against the planetary chill of a nuclear winter. Our line by then had survived five mass extinctions – as has every species with us now on the planet. We came out of the shadows into an emptied world – ready for our time in the sunlight.
All this and more lay stretched out for me in this ancient, weathered landscape. Human beings have reconstructed these events from innumerable clues, the growth of crystals, layers of mud, drift of DNA, matched rock formations on opposite sides of the Atlantic, aetosaur armor plates, phytosaur teeth and fossilized pollen. All the clues reinforce one another to make possible the reconstruction. The clues to extinction and evolution and the seasons of the earth lie scattered casually across the red and purple clays, themselves made of death and ash. The mineralized shroud of the ash actually harbored the makings of jewels and crystals we marvel at now.
A two-hour jaunt to the Petrified Forest from Payson lays bare all the great questions – fate and creation and the blind and heroic persistence of life. Something killed whole forests, washed the trunks into the lowlands and buried them so quickly with mineral-rich silt and ash they didn’t have time to rot. Instead, crystals replaced tissues to create an astonishing record of that vanished world.
The mystery lured me down the paved trail into the heart of the Chinle badlands, scattered with colorful chunks of petrified wood, tinted with iron, carbon, manganese and hematite – harboring crystals of clear quartz, purple amethyst and yellow citrine.
Lobo paced alongside on the leash, bound by the rules of the National Park Service. We both yearned to gambol out into the badlands on a treasure hunt, me for crystals to revel in and replace, him for scents to sniff and savor. But thieves pocket tons of precious petrified wood every year – so the Park Service insists we stay on the trails and solemnly swear at the gate that we have not stolen nothing.
I wandered through the badlands, seeing the signs of violence on every hand. Writing in the journal Science, Carnegie Institution and Columbia University researchers linked the mass extinctions that ended the Triassic to a massive outpouring of lava. In four great episodes in less than 600,000 years, volcanic basalt covered 2.5 million cubic miles of the earth’s surface – enough molten rock to bury the entire United States half a mile deep.
They dated these events using the radioactive decay of uranium isotopes in the rocks, the time-stamping of the flip-flopping of the earth’s magnetic poles, the layering of sediments in the bottoms of vast lakes that came and went, came and went. They gathered the clues left in the rocks and lakebeds to determine that the smoke of the volcanoes doubled the amount of carbon dioxide in the air. We’re on track to double the atmospheric carbon dioxide in our own time with smokestacks and exhaust pipes. Please note: the carbon dioxide levels then were already much higher than they are today. But then, they had no ice caps to melt – with all the land gathered at the equator. The smoke of the volcanoes caused temperatures to soar and the carbon dioxide made the oceans grew. It marked the fourth of five mass extinctions in the past 500 million years. Some say we’re losing species so fast right now that it qualifies as the sixth such event.
I tried to imagine the vanished world. But I was distracted by Lobo’s random lurches from one side of the path to the other. I figured he figured that if he ripped my wrist off he could sniff out some phytosaur scatt. He does not understand leashes – and for this I secretly admire him.
So I sat finally on a 225-million-year-old chunk of Araucarioxylon arizonicum, the official fossil of Arizona. My perch offered a fine view of the end of the world. I counted my blessings on my 10 exquisitely evolved fingers.
I felt bad for the atosaurs and the rauisuchia and even the toothy phytosaurs. But in truth, I wept crocodile tears. In my heart, I’m glad they left the world to us – although we’ve made a mess of it.
And as the shadows oozed up out of the ground, found a curious comfort in life’s persistence. Even if in our ignorance we engineer a mass extinction of our own, the world will rise from our ashes – the crystals of calamity.
And still the wind will blow.
The planet will spin.
The light will fade.
At just this moment, a raven rose, croaking. Lobo leapt. The leash lashed. I lurched off my Arraucarioxylon arizonicum – and came up with a mouthful of Chinle Formation: Ash, with a hint of citrine.