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National Park Service Park News U.S. Department of the In te ri or The offi cial newspaper Canyonlands of Canyonlands National Park Spanish Bottom, Colorado River Jurassic Journey BY LEN EISENBERG 185 MILLION YEARS AGO, DURING THE AGE pterosaur has the wingspan of a raven and OF dinosaurs known as the early Jurassic, a long stiff tail that ends in a wedge-shaped Utah was a very diff erent place. Instead of web of skin. rocky deserts, isolated mountains and deep canyons, sand dunes covered the state from Eventually, we arrive off shore of the main end to end. During rainy periods, lakes area of meadows and trees. In and out of formed in low areas between the dunes, the shadows we see head-high dinosaurs and life fl ourished in them. moving–possibly a group of Ammosaurus. Some are on all fours pulling at ferns; Today that great pile of sand is known as others rise up on thick hind legs to reach the Navajo Sandstone. It forms the cliff the tops of plants. There are two or three walls of Zion National Park, the petrifi ed larger individuals and a similar number dunes of Arches National Park, and mesa of smaller ones, probably adults and tops at the Island in Sky and Horseshoe off spring. While several make their way to Canyon districts of Canyonlands. In fact, the shoreline for a drink, one or more of one of the lakes is preserved at Horseshoe the adults watch for danger. In the Jurassic Canyon, revealing evidence of a fascinating world, it is not long in coming. It takes a trained eye: to most visitors, this rock outcrop might blend right in with the rest of Canyonlands' ecosystem. If we could travel back in time fantastic landscape. However, its origins are somewhat unusual: it was created by mircoscopic organisms to this lake, what might we see? during the age of dinosaurs. A large, meat-eating theropod makes a charge from the trees. The herbivores spin Returning to the early Jurassic, we fi nd a sea and rush along the shore, galloping on all of sand dunes stabilized by a living carpet fours. The predator has the angle and plows of dwarf fern and cryptobiotic soil. From into the group, snatching at the smallest. It above, the distant glint of silver and gold is butted off by the largest adult who turns from a refl ected Jurassic sun announces the in confrontation and blows a braying honk presence of a chain of lakes. The nearest at its foe. The meat-eater is too small to take lake is a few hundred yards wide and on this heavy, enraged animal and dodges nearly a mile long. The lakeshore is lined around it to pursue the rest of the herd. The with stands of conifers and cycads amid adult rushes after, braying and honking. meadows of ferns and horsetails. Some of The animals soon disappear from view the trees are a foot in diameter and 30 feet without any sign of slowing. Whew! Not high. wanting to push our luck, we swim back to our starting place and return to the present. Walking on the dunes, the thin crust of Evidence of a lake environment: pieces of petrifi ed wood (above left) and a dinosaur track (right) provide vegetation easily breaks apart under our more evidence that at one time Horseshoe Canyon was lakefront property. The Jurassic lake at Horseshoe Canyon feet. It probably wouldn’t take much of a is located just east and north of the climate shift to dry up the vegetation, the On the northern side of the lake, size of a skinny turkey. They could be a west side trailhead parking lot (see the lakes, and set the dunes in motion. It is a microscopic organisms deposit mats of group of Segisaurus. One scratches the sand bulletin boards for more information). sweaty 100 degrees out and a swim sounds limy sediment on the lake bottom, which is with a toe, then quickly thrusts down its Fossilized wood, microbial mounds, other good. As we wade into the lake, a group marked by winding trails of bottom-mining narrow jaws and comes up with a mouthful plant remains, as well as dinosaur and of shrimp-like forms hurry deeper into worms and snails. In places, these mats of sand and a wriggling crustacean. We wade invertebrate tracks have been found there the water. Some of them have translucent have built up into large microbial mounds. closer to get a better look, but they suddenly or in nearby areas. Skeletal remains are hinged shells on their backs. Vegetated It appears that if the lake level were to rise, raise their heads in unison and bolt. We very rare in the Navajo Sandstone and none dunes rise above the trees and meadows the living surface of the mound would keep stand in the shallows amid the horsetails, have been found at Horseshoe Canyon. back from the lakeshore. On one of the pace by growing larger. We notice that all impressed at how fast they can move. dunes a squat, dog-sized reptile is clawing of the mounds and most of the mats are Len Eisenberg is an independent geologist swipes of sand out of a hole. Its short, on the south-facing side of the lake, where Now a hand-sized green and gold dragonfl y living in Oregon. His main research interest strong arms have no trouble digging deep these photosynthesizing organisms receive hovers a few feet away. It chases a fl ying is the Navajo Sandstone, especially the into the dune and uncovering a nest of the most sun. bug, but then a young pterosaur, a fl ying indicators of unusual habitats and events wasp larvae. The creature licks up the reptile, fl ashes down and snatches the in it. An expanded version of this story and larvae, and its thick, bristly hide protects it Beyond the mounds we see three-toed dragonfl y from the air. As it fl ies away, the fossil evidence will be published by the from the angry parents. dinosaurs walking around, each about the gulping down its meal, we see that the Museum of Moab this year. TEACHERS! IT'S ALIVE! Red Rock Ad ven tures: A Teach er’s Guide to Canyon Coun try Outdoor Watch your step Ed u ca tion contains over 100 sci ence ac tiv i ties for grades one through as you're exploring six. Topics are taken directly from the Utah State Science Core the park. See the Curriculum guidelines and are corre lat ed to the National Science back page for more Standards. Download lesson plans and learn more about the program Thanks to you, improvements are being made information on at www.nps.gov/cany/education. throughout the park. See back page for details. living soil crusts. ..................................... ..................................... BY TIM GREEN National Park Service The Challenge of Drought U.S. Department of the Inte ri or AS THE HEAT RETURNS TO CANYONLANDS THIS perennials, especially trees and shrubs. However, during a drought even the spring and the pools and streams fi lled with Of these, the pinyon pine has been hit healthiest trees can suff er infestations. winter snowmelt diminish, a race begins. particularly hard. Lack of water decreases a tree’s ability Canyonlands Park News Trees, fl owers, animals – all living things to produce sap and causes a buildup of – will compete for water. But this race is Pinyon pines (pinus edulis) occupy a sugars in its cells. This makes the tree both Published By nothing new: drought is common in the signifi cant niche in canyon country, making better tasting (to a beetle, anyway) and Canyonlands Natural His to ry Association desert. Defi ned as an extended period of up nearly 60% of the forest cover in Utah. defenseless. Over the last fi ve years, this (CNHA), a nonprofi t orga ni za tion that assists lower than average precipitation, drought In the southeast corner of the state, they unfortunate combination has caused the the Na tion al Park Ser vice in its educational, has gripped the Canyonlands area since normally grow from 5,000 to 7,000 feet death of millions of pinyon pines in the in ter pre tive and scientifi c programs. CNHA’s 1999. above sea level. Pinyon pines contribute Four Corners region. Unless an army of goals in clude en hanc ing every vis i tor’s much to the desert ecosystem, including woodpeckers swoops in to eradicate the un der stand ing and ap pre ci a tion of public Lack of water tests the fi tness of plants and habitat for birds and insects, shade for beetles, this trend shows no sign of abating. lands by providing a selection of qual i ty, animals. Organisms that survive drought, overheated hikers, erosion control and, ed u ca tion al ma te ri als for sale at the park visitor centers. For more infor ma tion, whether by fi nding new water sources or of course, delicious nuts. However, a Interestingly, this large scale die-off contact CNHA at (435)259-6003, or visit tolerating some degree of dehydration, combination of circumstances now comes on the heels of twenty years of them online at www.cnha.org. pass on their abilities and genes to the next threatens the population of this important above average precipitation and forest generation. If droughts were abnormal, tree. growth. From 1976 to 1995, the southwest Editor they would be accompanied by a massive United States experienced some of its Neal Herbert die-off of plants and animals.