National Park Service U.S. Department of the Interior

Volume 8 Number 1 Park Paleontology Spring 2 0 0 4 Geologic Resources Division, Paleontology Program THE DIVERSITY AND STRATIGRAPHIC Table of Contents DISTRIBUTION OF PRE-DINOSAURIAN The Diversity and Stratigraphic Distribution of COMMUNITIES FROM THE TRIASSIC Pre-Dinosaurian Communities from the Triassic Moenkopi Formation, Capitol Reef MOENKOPI FORMATION, CAPITOL REEF National Park and Glen Canyon National NATIONAL PARK AND GLEN CANYON Recreation Area, Utah...... 1 NATIONAL RECREATION AREA, UTAH Discovery of Cretaceous Marine Reptiles at Glen Canyon National Recreation Area.. 4 Debra L. Mickelson Denali Geologist’s Name Graces Fossil... 5 Department of Geological Sciences University of Colorado at Boulder, UCB An Unlikely Giant in Capitol Reef National 399 Park...... 6 Boulder, Colorado 80399 [email protected] Fossils from Glen Canyon NRA Travel to France...... 7 Recent discoveries in the Moenkopi Lateral correlations of the Formation (Early Triassic) of Capitol ichnostratigraphic units identified in the Reef National Park (CRNP), and Glen Moenkopi Formation throughout Utah’s Canyon National Recreation Area National Parks will aid interpretations (GCNRA), Utah have revealed about the paleoecology, and diversity important new terrestrial and Location Map of Glen Canyon National of the Western Interior during the subaqueous vertebrate track localities. Recreation Area and Capitol Reef Middle Triassic-“the dawn of the National Park These well-preserved tracks occur on dinosaurs”. multiple stratigraphic horizons and are sandstones, containing abundant ripple the oldest and most laterally extensive marks and parallel laminations Significance track-bearing horizons documented in dominate lithologic types. Ichnites the Western U.S. Ichnogenera indicating swimming/floating behavior • Terrestrial tracks in an apparently (Chirotherium), (Rhynchosauroides), and are associated with the walking marine influenced facies of the (Rotodactylus), are the dominant forms. trackways. The water depth was Moenkopi Formation Rare fish fin drag marks (Undichna) and sufficiently shallow to permit the fish skeletal remains have been vertebrates to touch the substrate with • Distribution of Middle Triassic Pre- identified in the Torrey Member and manus and pedes when moving Dinosaurian Communities equivalent strata of the Moenkopi through the water. Formation. • Diversity of Middle Triassic Pre- Tracks form locally dense Dinosaurian Communities Tracks are preserved either as positive concentrations of toe scrape marks relief “casts” filling impressions in the which sometimes occur with complete There are Three Lines of Evidence of underlying mudstones or on plane bed plantigrade manus and pes impressions. Tidal Influence surfaces as negative relief Well preserved, skin, claw, and pad, “impressions”. Exposed traces occur impressions are common. Occasional, • Tidal point bars present on the undersides of resistant well developed, tail-drag marks sandstone ledges where the mudstone frequently occur in many of the • Presence of mud draped features; has eroded away and in finer grained trackway sequences. Fish fin drag pulses of water and suspended load sediments such as mudstones and marks and fish skeletal material are being dropped; an indication of siltstones. The Torrey Member preserved with tetrapod swim tracks. fluctuating currents represents deposition on a broad, flat- In addition to vertebrate ichnites, fossil lying coastal delta plain. Both invertebrate traces Arenicolites, • Presence of vertebrate and nonmarine (fluvial) and marine Paleophycus, Fuersichnus, invertebrate traces (principally tidal) processes influenced Kouphichnium (horseshoe crab), deposition. Even-bedded mudstones, centipede, and fossil plants of siltstones, claystones, and fine grained Equisetum are abundant. continued on page 2

Park Paleontology 1 Basal deposits of the Torrey Member Vertebrate Ichnology include interbedded siltstones, dolomites, and very fine-grained Chirotherium Tracks: Relatively narrow, sandstones that were laid down in quadrupedal trackways indicating the advance of the prograding delta. This normal tetrapod walking gait; in the sequence grades upwards into ledge- walking gait a small pentadactyl manus forming coarser grained sandstones and impression regularly occur immediately interbedded siltstones. Several track- in front of, but never overlapped by a bearing horizons are present within this much larger, pentadactyl pes which delta-plain facies. The facies includes generally resembles a reversed human channel deposits of large-scale trough hand. Manus and pes are digitigrade, and in large forms the pes tends to be Significance and Three lines of evidence cross bedded fine to medium grained plantigrade; digits I-IV point more or less forward, manus digits IV is always Geology The Torrey Member of the Moenkopi Formation has been the subject of investigation for almost 50 years. However, these studies were more broad based regional studies, and only recently has the Torrey Member been studied in stratigraphic detail with emphasis on the extensive tetrapod track-bearing surfaces of pre- Vertebrate tracks of Chirotherium. dinosaurian communities present Known to occur at Glen Canyon within it. At present, the multiple National Recreation Area and Capitol track-bearing horizons are known to Reef National Park. extend throughout much of Utah’s National Parks. Currently, the Torrey sandstone that was deposited within the fluvial-dominated reaches of the upperdelta-plain. Multiple tetrapod track horizons have been identified within these deposits. Vertebrate tracks of Rotodactylus. Channel bodies dominated by ripple to Known to occur at Capitol Reef National large-scale trough cross bedded Park. sandstones and interbedded mudstones shorter than III being largest; the are organized into inclined heterolithic footprints may or may not show packages. Also present within these specialized metatarsal pads. Clear sandstone and mudstone-dominated impressions often show a granular or channels are large-scale soft sediment beaded skin surface (skin impressions). deformational features and clay-draped Associated swim tracks are common ripple- and dune-scale bedforms. and often indicate current flow Tetrapod tracks and fish-fin drag marks directions and water depths. are typically associated with these deposits. These inclined barforms are Rotodactylus Tracks: Long-striding, likely pointbar deposits that trackways of a medium pentadactyl experienced tidal influence and may reptile are well preserved with rare represent the more seaward lower skin and claw impressions. These Stratigraphic measured sections of delta-plain expression of the sandstone- tracks commonly occur with smaller GCNRA and CRNP and Smith’s Model of dominated fluvial channels. Rhynchosauroides footprints. The “Meandering River Estuarine Systems “. manus is always closer to the midline A threefold lithofacies classification and in some cases overstepped even in Member vertebrate tracks are the model produced by Smith (1987) was the walking gait by the much larger oldest and most laterally extensive adapted to describe depositional pes in a moderately narrow trackway megatracksite horizons ever recorded. environments of the Torrey Member pattern; pace angulation (pes) as high delta-plain channels. Outcrop measured as 146 degrees in a running trackway Following the deposition of the Sinbad sections (a west to east trend) are and as low as 93 degrees in a walking Member in a clear shallow sea, a similar to Smith’s, (1987) lithofacies trackway. The pes impression change in tectonic and/or climatic classification for meandering river indicates a foot with an advanced conditions caused the progradation of estuarine systems. digitigrade posture, and with a strongly a major delta succession into Utah. developed but slender digit V rotated This delta complex is preserved as the to the rear where it functioned as a Torrey Member. continued on page 3

2 Park Paleontology rotated backward but it has a propping The fish fin trace fossils are preserved function. Digit IV on both manus and as convex hyporelief sandstone casts pes is longer than III; digit I may fail to with filled imprints preserved in impress; claws are evident and distinct underlying mudstone. Exposed traces on digits I-IV. Scaly plantar surface occur on the undersides of resistant (well defined skin impressions) are sandstone ledges where the mudstone often preserved in exquisite detail and eroded away. Undichna commonly is characterized by transversely occur with locally dense concentrations elongate scales on the digit axis of swim traces of Chirotherium. bordered by granular scales. Occurring in clusters, one isolated fish Rhynchosauroides Tracks: Dense fin trace consists of a single, slightly- Invertebrate trace fossils of concentrations of Rhynchosauroides asymmetrical, sinusoidal trail. The Fuersichnus, Palaeophycus, Arenicolites. tracks are commonly associated with trace is 56 cm. Long and includes 6.5 Known to occur at Glen Canyon the trackways of Chirotherium and cycles with wavelengths varying from 9 National Recreation Area and Capitol Rotodactylus. These small lacertoid to 10 cm and amplitudes of 3.5 to 4.5 Reef National Park. footprints are generally characterized cm. dwelling structure probably produced by deeply impressed manus and a by crustaceans or polychaetes. faintly impressed pes. Trackways The trails were most likely produced by exhibit a relatively wide pattern with a fish with a large caudal or anal fin The ichnogenus Palaeophycus a pentadactyl footprint relatively distant able to reach the sediment without any common trace fossil that has been from the midline. The pace angulation other fin doing so. The low documented from Pre-Cambrian to is low, below 90 degrees – 100 –120 wavelength to amplitude ratio is most Holocene nonmarine and marine consistent with a caudal fin. This deposits. Branched, and irregularly occurrence of Undichna is similar to winding, cylindric or subcylindric tubes, other previous descriptions and it that sometimes cross-cut one another. confirms that the preservation of these These horizontal galleries most often trails are favored in fine-grained have vertically striated lined burrows or sediments. Importantly, these traces rarely nearly smooth surface textures. coupled with Chirotherium, and Palaeophycus represents passive Rhynchosauroides, swim tracks, all sedimentation within an open dwelling indicate fluctuating water depths. burrow constructed by a predaceous or Vertebrate tracks of Undichna (fish fin suspension-feeding animal. drag marks). Known to occur at Glen Invertebrate Ichnology Canyon National Recreation Area. The ichnogenus Arenicolites are simple degrees if figured from the manus Fuersichnus, Palaeophycus, and U-tubes (paired tubes) without pattern. Most often only 3 to 4 digits Arenicolites: The Torrey Member of the spereite, perpendicular to bedding are preserved with occasional tail drag Moenkopi Formation assemblage plane; usually varying in size, tube marks. The digits are slender and studied is considered herein as an diameter, distance of limbs, and depth relatively longer in the pes than in the example of the Glossifungites of burrows; limbs rarely somewhat manus and both sometimes exhibit ichnofacies and commonly occur with branched, some with funnel-shaped distinct claw impressions. Swim tracks vertebrate swim tracks. This opening; walls commonly smooth. A are common. ichnofacies has been restricted to firm common trace fossil documented from but unlithified nonmarine and marine Triassic to Cretaceous from marine and Undichna Fish Trails: The Moenkopi surfaces. The Glossifungites nonmarine deposits. The Torrey Formation is known for its exceptional ichnofacies is characterized by low Arenicolites are very consistent in size, vertebrate fossil record. Fish are rare diversity and high density assemblages shape, and distance apart from each and have been little studied in detail, which include Fuerichnus, other and are interpreted as made by and fish trails (fish fin drag marks) have Palaeophycus, Arenicolites, and annelid worms. never been recorded. The purpose of Skolithos. this study is to describe the first known Summary occurrence of fish trails (fish fin drag The ichnogenus Fuersichnus is a • Occurrence of terrestrial and sub- marks), Undichna from the Early relatively rare trace fossil that has been aqueous tracks in the Moenkopi Triassic Torrey Member of the documented from Triassic and Jurassic Formation. Moenkopi Formation. This ichnogenus nonmarine deposits and only recently has been reported in abundance from documented in marine deposits from • Tracks occur in marine influenced the Late Paleozoic, Permian, the Upper Cretaceous . The environments. Cretaceous, and more recently from ichnogenus consits of horizontal to the Eocene. Undichna from the Torrey subhorizontal, isolated of loosely • Implication is that these animals Member of the Moenkopi Formation clustered, U-shaped, curved to banana- may have tolerated brackish water represents the first and only known like burrows, characterized by conditions. occurrence of fish trace fossils in the distinctive striations parallel to the Triassic in the Western U.S. trace axis. It is interpreted as a continued on page 4

Park Paleontology 3 Discussion McKee, E.D., 1954. Stratigraphy and Discovery of History of the Moenkopi Formation of Several important discoveries have Triassic Age: The Geologic Society of Cretaceous Marine been made during the course of this America Memoir 61:1-133. research in GLCA and CARE. The Reptiles at Glen Torrey Member of the Moenkopi Mickelson, D.L., Huntoon, J.E., Canyon National Formation trackways are first Worthington, D., Santucci, V.L., Clark, described in detail from this T, 2000. Pre-dinosaurian community Recreation Area stratigraphic unit and suggest a great from the Triassic Moenkopi Formation potential for finding other footprint Capitol Reef National Park: Geological David D. Gillette sites in this Formation. This unit is Society of America (Abtracts) 32(7). Museum of Northern Arizona widely exposed not only in Capitol 3101 N Fort Valley Road Reef, and Glen Canyon Recreation Peabody, F.E., 1948. Reptile and Flagstaff, Arizona 86001 Area, but also, Zion, Canyonlands, and amphibian trackways from the Lower [email protected] Arches, National Parks. Lateral Triassic Moenkopi Formation of Arizona correlations in Utah’s National Parks of and Utah. University of California, Ninety million years ago dinosaurs ruled the Moenkopi’s extensive track bearing Bulletin of the Department of the land on a globe that had been horizons provide a good basis for Geological Sciences 27: 467 p. inundated by rising sea level. The correlation with the entire region. North American continent had become Smith, D.G., 1987. Meandering river two islands separated by an inland As a non-renewable resource on public point bar lithofacies models: Modern seaway that isolated eastern North lands, fossil footprints provide an and ancient examples compared: pp. America from western North America. opportunity for public education, 83-91 in Ethridge, F.G., Flores, R.M., That shallow sea became home for a scientific research, monitoring and Harvey, M.D., (eds.). Recent myriad of sea-going animals and plants programs, and an administrative Developments in Fluvial Sedimentology that we now find as fossils in the opportunity and challenge for both Contributions from the Third shales and limestones that scientists and land management International Fluvial Sedimentology accumulated in the Cretaceous Inland authorities. Conference, The Society of Economic Sea. During the past five years, Paleontologists and Mineralogists, paleontologists from the Museum of Additional Reading Special Publications 39. Northern Arizona and our colleagues have discovered a variety of new and Blakey, R.C., 1973. Stratigraphic and Smith, J.F. Jr., Lyman, L.C., Hinrichs, sometimes spectacular marine origin of the Moenkopi Formation E.N., and Luedke, R.G. 1963. Geology vertebrates from the Tropic Shale, (Triassic) of Southeastern Utah. The of the Capitol Reef Area, Wayne and which represents the accumulation of Mountain Geologist 10(1):1-17. Garfield Counties, Utah: Geological muds and siltstones in that warm, Survey Professional Paper no. 363:99 tropical sea. The most abundant are Blakey, R.C., 1977. Petroliferous pp. the plesiosaurs, giant marine predators lithosomes in the Moenkopi Formation, that competed with sharks as the Southern Utah: Utah Geology dominant terrors of the Cretaceous 49(2):67-84. What Is Ichnology? sea. Hintze, L.F., 1988. Geologic History of Our field investigations have focused Utah: Brigham Young University Fossils can be divided into body fossils, on the Cretaceous vertebrate fauna of Geology Studies Special Publication 7: preserved parts of the plant or animal, and trace southern Utah in Glen Canyon National fossils, indirect evidence of their presence. 202 pp. Ichnology is the study of plant and animal Recreation Area (National Park Service) traces. The implication of this definition is that and Grand Staircase-Escalante McAllister, J.A., 1989. Dakota the traces made by plants and animals reflect Formation tracks from Kansas: some sort of behavior or in the case of animals continued on page 5 their mode of locomotion. The best known Implications for the recognition of trace fossil are tracks but burrows, nests, and tetrapod subaqueous traces. pp. 343- gnaw marks on bones or plants are also types 348. in GIillette, D.D., and Lockley, of trace fossils. Ichnology can be divided into two major M.G., eds., Dinosaur Tracks and subdivisions: paleoichnology (the study of Traces: Cambridge University Press, ancient traces) and neoichnology (the study of New York, modern traces). Most ichnologists are involved in paleoichnology but a considerable number also study neoichnology for the comparison of McAllister, J.A., and Kirby, J. 1998. An modern equivalents (and their trace makers) to occurrence of reptile subaqueous ancient traces. Technically speaking, wildlife traces in the Moenkopi Formation biologists or ecologists who study tracking (identification of animals and their behavior on (Triassic) of Capitol Reef National Park, the basis of their tracks and feces) are South Central Utah, USA. Journal of neoichnologists, although they probably would Paleontologists from the Museum of Pennsylvania Academy of Science, 71, not recognize such an designation if you told Northern Arizona answer questions Suppl. And Index:174-181. them. about the plesiosaur during an open http://www.emory.edu/COLLEGE/ENVS/ house at Glen Canyon National research/ichnology/ Recreation Area

4 Park Paleontology . from two individuals, one from Glen Canyon National Recreation Area, the other from Grand Staircase-Escalante National Monument, making this exhibit an interagency display. During the 2003 field season we completed the excavation of another partial skeleton from an individual that was twice as long: at least 40 feet in length and several tons in total weight. Although we did not recover bones Myriospirifer breasei Dorsal view from the head, we can estimate that the skull and jaws were nearly eight feet long. And that’s not the largest: we have discovered incomplete skeletons, mainly vertebrae, from a variety that’s even larger. The plesiosaur, Trinacromerum, as it was found at Glen Canyon National Some say the Age of Dinosaurs was a Recreation Area. dangerous time to live on land. We say National Monument (Bureau of Land that the Cretaceous Sea during the Management) where continuous Age of Dinosaurs was the most exposures of the Tropic Shale offer dangerous place to live! unparalleled opportunity for studies on biodiversity of the final stages of the Age of Dinosaurs. Plesiosaurs seem to Denali Geologist’s Name be the most abundant, and certainly Graces Fossil the largest of the Cretaceous marine predators in the Tropic Shale fauna. From several partial, but nevertheless While any employee of the National Phil Brease, geologist at Denali National spectacular skeletons, we have pieced Park Service can names lots of fringe Park together enough to display one benefits of working in parks, one of García-Alcalde, J.L. and R.B. Blodgett. 2001. example of the genus Trinacromerum, the more unusual ones is to have a New lower Devonian (upper Emsian) Myriospirifer (Brachiopoda, Eospiriferinae) a short-neck plesiosaur with the ability fossil named after you. The recipient of this rather unusual claim to fame is species from Alaska and northern Spain and to swim at astounding velocity, by the paleogeographic distribution of the genus some calculations as fast as 30 miles Phil Brease, an NPS geologist at Denali Myriospirifer. Journal of the Czech per hour or more. That mounted National Park and Preserve. A fossil Geological Society 46(3-4):145-154. skeleton was on display at the Museum Devonian brachiopod from the park of Northern Arizona from April 2003 was described as a new species of until May 2004. It is now scheduled to Myriospirifer, M. breasei by Jenaro L. Brachiopod become a year-long exhibit in 2004 and García-Alcalde and Robert B. Blodgett or 2005 at the John Wesley Powell in the Journal of the Czech Geological Museum of Page, Arizona, the town Society. Blodgett is a geologist with Bivalve? closest to the field area in Glen Canyon the United States Geological Survey in National Recreation Area. Anchorage, Alasaka that specializes in While brachiopods and bivalves (also known brachiopods. The brachiopod was as pelecypods) look superfically similar because they have two external shells, they That mounted skeleton is about 20 feet found by Blodgett, Brease, and Pam are quite different. In fact they are placed in long, with a skull and jaws more than Sousanes during a research trip in the two seperate phyla, with brachiopods in their four feet long and containing about park in July 1996. A member of the own phylum and bilvalves are placed within 100 piercing teeth. It is a composite subfamily Eospiriferinae, this genus of the phylum Mollusca. One way to tell a brachiopod was widespread within brachiopod from a bivlave is the plane of Gondwana and Baltica during the symmetry - where the line goes that divides Devonian. Its presence in Alaska is the animal into mirror images. In the interpreted as being the result of brachiopods the plane of symmetry is at a right angle to the shell, while in in a bivalve transport on accreted terrane rifted the plane of symmetry passes between the from Sibera and joined to North two valves of the shell so each half of the America during the late Mesozoic. shell is the mirror image of the other.

Brachiopods also have a structure known as a pedicle which they use to attach to rocks Answer to name the fossil and the park. This is a while bivalves have a muscular foot. Bivalves portion of a fossil termite burrow preserved in breath and gather food using gills while a Paddle of the plesiosaur during the Navajo Sandstone at Glen Canyon National brachipod does this with a structure known excavation. Recreation Area. as a lophophore.

Park Paleontology 5 An Unlikely Giant in stumbled across what he described looked “almost like a giant haystack” Capitol Reef National or “a giant limestone onion slowly being peeled.” This turned out to be Park the serendipitous discovery of the first known stromatolite in the Navajo Len Eisenberg Sandstone and possibly the first 223 Granite Street stromatolite within an erg setting. Eisenberg, an independent geology Ashland, Oregon 97520 consultant, spent the next several [email protected] years researching the occurrence and the discovery was reported in the Jay Chapman February, 2003 issue of Geology. 370 South 36th Street Boulder, Colorado 80305 Stromatolites are bizarre fossils whose [email protected] biological origins were debated until only a few decades ago. Today, The discovery of giant stromatolite scientists generally agree that fossils in the Navajo Sandstone is part The Capitol Reef Stromatolites stand out stromatolites are layered colonial like “haystacks” from the surrounding of a growing body of research structures predominately formed by rock because they are composed of challenging some long-held cyanobacteria. Stromatolites are the limestone, which is more resistant to assumptions about the oldest fossils on earth, dating back to weathering in a desert environment paleoenvironment of the Navajo erg. more than three billion years ago. than the surrounding sandstone. They were the dominant life form on The Navajo Sandstone, a prominent earth for over 2 billion years and are some point,” although this is the first and well-exposed rock unit in the thought to be primarily responsible for direct evidence of such stabilization. Colorado Plateau, was once an the oxygenation of the atmosphere. Modern ergs are known to periodically enormous, arid sea of blowing sands Living and fossil stromatolites are stabilize, a recent example being the (called an erg) often compared to the usually no more than half a meter tall “greening period” of the Sahara present Sahara Desert. This early and are found in marine environments. between four to ten thousand years Jurassic dune field covered close to half In contrast, the Capitol Reef ago. Using growth rates for modern a million square kilometers and Stromatolites are up to five meters in stromatolites, it can be determined reached thicknesses in excess of 700 height and appear in thin carbonate that the fossil stromatolites grew over meters making it one of the largest beds associated with interdune a period of a few thousand to over ten dune fields in the history of Earth. deposits. thousand years, putting them “right in the ballpark, …in the thousands of Although the Navajo erg is generally The most important implication of the years range,” with the duration of the thought to have been an expansive fossils is the suggestion of large bodies Sahara stabilization. and lonely desert, new fossils found in of standing water necessary to sustain Capitol Reef National Park suggest the towering stromatolites. “We need If the Navajo erg stabilized for thou- otherwise. During an extended to reevaluate the whole sands of years, it would mark a major backpacking trip, the senior author paleoenvironment,” David Loope of the stratigraphic boundary within the University of Nebraska-Lincoln says. Navajo Sandstone. Right now, “the “Until we had the stromatolites the continued on page 7 general picture was hyper-arid,” he says. Dr. Marjorie Chan of the University of Utah agrees, saying that What Are despite the dry and dusty impression of Stromatolites? the Navajo erg, “it in fact had water and lakes.” A stromatolite is produced by cyanobacteria. The distinctive layers are produced as This is a dramatically different picture calcium carbonate is precipitated over the of the Navajo than previously thought. growing mat of bacterial filaments. The Navajo erg “may not be analogous Photosynthesis in the bacteria depletes carbon dioxide in the surrounding water and to the present Sahara” in that it had makes it less acidic thus initiating the the “potential for heavy rain and long precipitation of the calcium carbonate. The lived episodes of water,” Loope says. minerals, along with grains of sediment Long lived episodes of water would precipitating from the water become also translate into extended periods of trapped within the sticky layer of mucilage During the roughly 15 million years in erg stabilization. that surrounds the bacterial colonies. As the which the Navajo was deposited it colony continues to grow upwards through spread out over seven states, reaching Researchers have long “suspected that the sediment a new layer is formed. As this its maximum thickness in what is today process occurs over and over again, the Zion National Park. the Navajo must have stabilized at layers of sediment are created.

6 Park Paleontology Navajo is a big pile of sand and it’s hard Fossils from Glen to know where you are stratigraphically,” Canyon NRA Travel

“The next step is the “correlation of to France these scattered outcrops” to help “unravel the internal geometry and Glen Canyon National Recreation Area history of the Navajo erg.” has a wide variety of fossils. While those associated with the Jurassic Further correlation of interdune Navajo Sandstone are perhaps the best carbonate deposits could also suggest known, fossils at Glen Canyon also a regional climatic event, helping to includes remains from the Ice Age. improve climatic models of the Early The dry arid environment of the region Jurassic. helps preserve soft tissue and organic material including skin, horn and hoof “There is variability that we never coverings and dung that is not often realized that was there,” Chan says. preserved in the fossil record. Often “Just when you think you know it all, the preservation is just as spectacular we discover there’s a lot we didn’t as the better known frozen fossils of know.” The stromatolites in Capitol Siberia and Alaska. The same Navajo Reef National Park have renewed Sandstone that includes dinosaur interest in the Navajo Sandstone and tracks and termite nests often provide insight into the biology and The best modern analogues to fossil weathers to form sandstone overhangs environmental history of the Navajo stromatolites can be found in Shark Bay, or alcoves. During the Ice Age animals, erg, all from a walk in the Park. Australia (above). Similar organisms, including mammoths, shrub oxen and identical in form and structure, can be ground sloths often used these alcoves Additional Reading found in the outlet channel of Octopus for shelter and evidence of their Springs in Yellowstone National Park presence is indicated by not only their (below). Living stromatolites are rare Caine, J.S. and S.R.A. Tomusiak. 2003. preserved remains but their dung as today and are usually only found in well. Brittle structures and their role in hyper-saline waters. controlling porosity and permeability in a complex Precambrian crystalline-rock The Muséum National d’Histoire aquifer system in the Colorado Rocky Naturelle Paris, France has recently Mountain Front Range. Geological opened an exhibit entitled “Au Temps Society of America Bulletin des Mammouths”, (The Time of the 115(11):1410–1424. Mammoths” which will be open from Eisenberg, L. 2003. Giant stromatolites March 17, 2004 to January 10, 2005. and a supersurface in the Navajo The exhibit is in The Grande Gallerie de Sandstone, Capitol Reef National Park, l’Evolution. 36, rue Geoffroy Saint- Utah. Geology 31(2):111–114. Hillaire. Among the various fossils included in the exhibit is dung of the Riggs, N.R., S.R. Ash, A.P. Barth, G.E. Gehrels and J.L. Wooden. 2003. extinct Columbian Mammoth from Isotopic age of the Black Forest Bed, Glen Canyon National Recreation Area Petrified Forest Member, Chinle on loan from the park to the museum. Formation, Arizona: An example of Arrangement of the loan was done dating a continental sandstone. through Chris Kincaid, curator at the Geological Society of America Bulletin PLEASE NOTE 115(11(:1315–1323. park and Linda Clement, Staff Curator for the Rocky Mountain Region Walsh, P. and D.D. Schultz-Ela. 2003. working with Jim Mead of Northern Mechanics of graben evolution in The fossil stromatolites at Capitol Reef Arizona University. Dr. Mead along Canyonlands National Park, Utah. are not easily accessible and somewhat with Dr. Larry Agenbroad of the Geological Society of America Bulletin hard to find. If you’re up for a long university was involved in the original 115 (3):259–270. day-hike or an overnighter, one of the best locations to see the stromatolites is excavation or the site and its scientific Web sites located along Cottonwood wash in the study. Study of the dung has shown it http://www.sharkbay.org/ central-eastern section of the Park. is composed of 95 % grasses and Always check in with the park staff terrestial_enviroment/page_15.htm sedges and has provided important beofre going on any overnight or extended trips into the back country of information about the diet of these National Natural Landmark site the park. As always, removal or extinct animals. http://www.petrifiedseagardens.org/ vandalism of any fossil is strictly stromat.htm prohibited. The web site for the exhibit http://www.mnhn.fr/mammouths/

Park Paleontology 7 National Park Service First Class Mail U.S. Department of the Interior Postage and Fees P A I D Natural Resource Program Center City, State Geologic Resources Division Permit number Paleontology Program P.O. Box 25287 Denver, Colorado 80225 303 969-2821

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Park Paleontology is published intermittently each year by the Geologic Resources Division. It is available as a PDF file on the Internet at http:www2.nature.nps.gov/grd/geology/ paleo/news/newsletter.htm Copies may be printed from the internet for free distribution.

Editor Greg McDonald

Contributors Jay Chapman Len Eisenberg David Gillette Debra MIckelson

Comments? Write to: Greg McDonald Geologic Resources Division National Park Service Name the fossil and the park. Hint: The park contains a large P.O. Box 25287 artificial lake named for a geologist. Answer on page 5. Denver, Colorado 80225

8 Park Paleontology