Fossil Plants And Insects At Bull Run, Nevada

A famous fossil site way off the beaten track

The Bull Run Fossils Contents:


Text: The Field Trip

Images: On-Site

Images: Fossils

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Links: USGS Papers

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Take a virtual field trip to a famous 37 million-year-old fossil locality in Nevada where many excellently preserved winged seeds and needles from conifer trees, plus fossil insects can be collected from what geologists call the upper Eocene Chicken Creek Formation. Explore the fossil remains of an essentially pure montane conifer forest--one of the few such paleobotanical associations yet described from the Tertiary Period of North America.

For folks unfamiliar with the rules and regulations regarding the collection of fossil specimens and other resources on Public Lands, visit the informative Bureau of Land Management (BLM) online brochures, Fossils On America's Public Lands and Collecting On Public Lands.

The Field Trip

An excellent region in which to prospect for a wide variety of nicely preserved plant and animal fossils is the Bull Run Basin district, Nevada. Here can be found winged flying seeds (or samaras, botanical terminology) and fascicles (bundles of needles) from several species of conifers, ostracodes (a minute bivalved crustacean), freshwater gastropods, plus rather common carbonized insect larvae. The paleontological specimens occur in the upper Eocene Chicken Creek Formation, whose fossiliferous horizons have been dated by radiometric means at some 35 to 37 million years old. Although the region is quite remote, well off the proverbial beaten track, Bull Run Basin nevertheless remains quite popular among amateurs and professional paleobotanists alike, owning to its virtually unique abundant association of late Eocene conifer remains that demonstrate clearly that some 37 million years ago this portion of the Great Basin district supported an essentially pure montane conifer forest.

I first learned of this particular fossil-bearing district, by the way, from a citation in a United States Geological Survey Bulletin. Here is a partial quote of that original citation: "Discussion of potassium-argon ages of some western Tertiary floras. Sample of Chicken Creek Formation is from a 20-foot bed of biotite rhyolite ash 5 feet above uppermost of 10 florules that comprise the Bull Run Flora. Radiometric age of 35.2 million years indicates this florule is basal Chadronian or transitional Eo-Oligocene and the florules stratigraphically below it are Duchesnean or latest Eocene." Note that, according to the current Geologic Time Chart referenced by most paleontologists, the Oligocene Epoch of the Tertiary Period began about 34 million years ago (well...that would of course be 33.9 million years ago, if one requires unerring exactitude)--hence, the fossil floras preserved in the Chicken Creek Formation can faithfully be assigned to the late portions of the Eocene.

Many fine fossil plant localities occur in the Bull Run District. Exposed here are extremely fine-grained, dark-greenish shales and mudstones bearing common winged seeds and fascicles from many species of conifers, including fir (Abies), pine (Pinus), spruce (Picea), larch (Larix), hemlock (Tsuga) and cypress (Chamaecyparis)--all of which specimens can be collected from the upper Eocene Chicken Creek Formation, named by paleobotanist Daniel I. Axelrod in an unpublished manuscript. Rarer finds, comprising less than 1 percent of the fossil flora--over 8,000 plant specimens have been taken from the Chicken Creek Formation by paleobotanists for study--include the leaves of alder, birch, zelkova, Oregon grape, maple (samaras are also found), willow, and cottonwood.

Much digging and splitting of the shales will be required to find the best representation of fossil plant specimens. Since the fine-grained sedimentary rocks accumulated in the deepest portions of the ancient late Eocene lake, plant structures transported there by storm waters far from the shoreline were preserved in the muds and silts only under the most favorable circumstances. This means that many shale beds are barren of botanic specimens, while others, without any apparent differences in lithology from the rocks lacking fossils, yield significant concentrations of conifer winged seeds and associated fascicles, or small bundles of needles that originally were attached to the branches. A moderate amount of picking through the shales and mudstones should soon help you determine which horizons will provide enough fossil specimens to allow a successful quarrying operation. Even though the conifer seeds and fascicles are rather small, they are nevertheless readily identifiable in the sediments, carbonized an attractive brownish-black on the dark green shales.

Some collectors thrive on the opportunity to open up a fossil quarry in a productive plant-bearing region, choosing to concentrate their efforts at one or perhaps two favorable locations. Other fossil plant seekers prefer to "hit and miss," as it were, hiking over the outcrops and collecting specimens from surface exposures. Both methods will net many well-preserved remains here, but if you choose to undertake a major quarrying excavation, be sure to open up your fossil pit at a site well-removed from the main dirt roads. While it is certainly permissible to dig a bit in the roadcuts, be careful not to probe through a great quantity of shales, tossing the debris back onto the roads.

When last in the region, I spent but a partial day splitting shales at Bull Run and was able to secure an excellent selection of well-persevered seeds and fascicles from several species of conifers, primarily spruce and fir. During a number of previous visits, I enjoyed whacking (a genuine paleobotanical term denoting enthusiastic wielding of a rock hammer) into the shales at a supremely productive quarrying excavation were I invariably managed to recover a satisfying number of beautiful plant specimens--although admittedly my glory hole of paleontological gold had begun to produce progressively fewer paleotological structures not soon before I decided to explore elsewhere.

The fossil floras from the upper Eocene Chicken Creek Formation--there are no fewer than ten stratigraphically separate fossil plant-bearing horizons exposed at Bull Run Basin--have yet to be described in a formal scientific monograph; however, the late paleobotanist Daniel I. Axelrod had the area under serious study for several years. Axelrod gave a brief analysis of the flora in one of his many paleobotanical monographs. He noted that the fossils from the youngest horizons in the Chicken Creek Formation were comprised of fully 99.5 percent montane conifers. Based on the known environmental requirements of living representatives of the fossil flora, the average year-round temperature during late Eocene times was somewhere between 53.5 and 53 degrees Fahrenheit, an effective temperature gradient that suggests that the fossil species lived close to subalpine conditions, or more specifically in the montane conifer forest zone. Axelrod estimated that 37 million years ago the plants lived at an elevation of some 4,000 feet--today, the area lies at slightly over 6,000 feet in the midst of the arid Great Basin Desert. Yet, according to Axelrod the local paleogeography alone is apparently not enough to explain why the Chicken Creek plant community was essentially a pure conifer forest; a moderate elevation of 4,000 feet during the late Eocene would seem an insufficient reason to account for the rarity of deciduous trees and shrubs in the fossil record. According to Axelrod, the explanation was that a pronounced overall cooling trend during Bull Bun Tertiary Period times influenced the kinds of plant communities that supplanted those found in older sections of the Chicken Creek Formation, which yield a wider variety of species.

In recent years, though, much more information has been gathered on the paleoenvironment and related paleoelevations of the Early Tertiary Period. For example, the late paleobotanists Howard Schorn (former retired Collections Manager of fossil plants at the University California Museum of Paleontology) and the Jack Wolfe (former member of the United States Geological Survey), among others, have demonstrated through a combination of geophysical and sophisticated leaf character analyses data (a complex methodology in which such factors as leaf size and shape, in addition to ratios of entire to serrated margins of leaves are compared to approximate paleoelevations during the geologic past) that throughout Eocene, Oligocene, and early middle Miocene geologic times the ancestral Great Basin existed as a vast high plateau region that likely stood as high, if not higher than most of the present-day Nevada mountain peaks; hence, Schorn and Wolfe suggested that the Chicken Creek Flora likely accumulated at elevations well over 8,000 feet. Then, by 6.8 million years ago, through extensional geologic forces which helped create the modern physiographic province we observe today, the Great Basin had dropped to roughly its present elevations during the latter portions of the Miocene Epoch.

In addition to conifer winged seeds and occasional leaves, fossil insects can also be recovered from the upper Eocene Chicken Creek Formation. Most of the insect specimens occur in the greenish-brown fissile shales which, happily for the collector, erode in platy slabs from the exposures, a mode of weathering that has produced abundant material through which to search for elusive paleontological remains--in this case, winged conifer seeds and insects carbonized an aesthetically pleasing dark brown on the paler-colored matrix.

While insect exoskeletons are common to abundant (at least they used to be; loads of paleoentomology enthusiasts have with ebullient excitement swarmed over the productive shale exposures in recent years) in several of the shale layers at Bull Run, the exact identification of them remains in doubt. Since no wings or legs can be observed on the insect fossils, it is assumed by most collectors that they represent some sort of immature arthropod stage, or instar, perhaps a variety of fly larvae similar to types sometimes noted in oil shales of the famous Eocene Green River Formation of Colorado, eastern Utah, and Wyoming (some of the sedimentary beds in the Chicken Creek Formation have also been identified as oil shales). There are no museum-quality insect finds here, unfortunately, and the fact that the localized exposures still exist and have apparently survived hordes of collectors over the decades testifies to the fact that most visitors simply content themselves with a few select samples of insect-bearing shale and then move on to other sites. The conifer samaras are far rarer in the insect-bearing sections, but the specimens, when found, appear to be significantly larger than their counterparts at places where only plants constitute the paleobotanical association.

The Chicken Creek Formation is decently exposed at Bull Run. Visitors would be advised to conduct reconnaissance of all outcrops encountered. A few of the more marly sedimentary rock types in the area yield abundant tests of the minute bivalved crustaceans called ostracods. Genera identified from the Bull Run Basin include Cadonia, Tuberocyprise and Cypridopsis. It is illuminating to note that modern Cadonia ostracodes inhabit quiet freshwater lakes, where they typically creep and burrow in the silts and muds. Even though none of the ostracods found in the Chicken Creek marl beds is particularly well preserved, their fragmental and occasional complete shells often constitute a large proportion of the strata in which they occur. Such ostracod accumulations cannot properly be termed coquinas, although their concentration in the sedimentary rocks is such that a casual inspection might lead to this conclusion. Also, coiled freshwater gastropods of the genus Planorbis can be found in a few of the more heavier-bedded, ledge-forming outcrops of carbonaceous shales; such specimens are not particularly abundant, though.

An interesting sidelight is that the Chicken Creek Formation was originally called the Upper Miocene Humbolt Formation; geologists now conclude, of course, that the Bull Run strata belong to the late Eocene Epoch. The initial age determinations were based on suites of fossil plants collected from horizons not officially calibrated by radiometric isotope techniques. All of the conifers and deciduous varieties first studied from the Bull Run Basin in the early 1960s appeared diagnostic of the middle Miocene age, or roughly 15 to 13 million years old. When radiometric measurements were finally used on volcanic rocks both immediately overlying and underlying the fossiliferous sequence, paleobotanists were surprised to learn that the Chicken Creek beds could be accurately bracketed between 42 and 35 million years old. And, since the vast majority of the fossil florules in the Bull Run district occur in the sedimentary section roughly 600 feet below the rhyolite ash bed which gave a radiometric age of 35 million years, most paleobotanists believe that so the so-called Bull Run Flora is on the order of 37 million years old, or late Eocene in geologic age.

Traditionally speaking, the most comfortable times for visiting Bull Run Basin are from mid spring through mid fall. A few hardy souls brave the winter--invariably local collectors from surrounding Great Basin territories who must contend with such arctic-style meteorology on a regular basis--but for most temperate-climate residents the prospects of experiencing subzero temperatures combined with frequent lacerating winds tends to chill the paleontological enthusiasm somewhat.

Bull Run Basin lies right in the middle of the sparsely populated Great Basin Province, many miles from the nearest community where mechanical or medical assistance can be found. It is imperative that visitors to the district observe the traditional rules of backcountry travel. Now, depending on the creativity of the person suggesting the necessary precautions to observe, the list of "traditional rules" varies from a few trenchant admonitions to an unwieldy didactic tome. Since I regularly conduct my paleontological excursions in an average-sized four-wheel drive vehicle, I have little room to carry with me a redundancy of emergency supplies. I prefer to keep matters uncomplicated: 10 gallons of water; two or three days' worth of provisions; spare fan belts; heavy-duty blanket and trusty Antarctica jacket (purchased during my stay in Kansas several years ago during chill factors of minus 35 degrees); hydraulic jack and lug wrench; insect repellent (most frequently used emergency item--one particular species of biting gnat--"black fly"--common to Nevada devastates my system); battery-operated radio; flashlight; and various officinal preparations such as aspirin, rubbing alcohol, and a topical antibiotic. I also have citizens-band radio capabilities, but have never had the need to broadcast an emergency plea.

As a member of the inspiring Great Basin physiographic province, Nevada today holds many fascinating fossil plant and animal localities--paleontological sites that tell tales of more temperate climates in the geologic past, many millions of years ago when forests of moist green thrived around extensive pristine lakes whose slowly accumulating sediments now lie exposed in a setting of pastel aridity. In the Silver State of Nevada, at Bull Run Basin, fossil enthusiasts may dig into the hardened muddy remnants of what existed here some 37 million years ago: a great body of fresh water around which grew luxuriant stands of spruce, fir, pine, larch, hemlock, and cypress--a pure montane conifer forest, one of the few such botanic associations recorded in the Cenozoic rocks of North America. It must have been a scene which rivaled modern Lake Tahoe in the high Sierra Nevada: a shimmering expanse of cold deepness reflecting skyward the pitch-scented density of conifer green.

On-Site Images

Click on the images for larger pictures

Click on the image for a larger picture. A paleobotany enthusiast searches for fossil remains. Here, the view is looking essentially due north from a fossil plant locality in the upper Eocene Chicken Creek Formation, Bull Run Basin, Nevada. The extremely fine-grained, dark-greenish shales here yield many excellently preserved 37 million-year-old conifer remains, including the winged seeds and needles of spruce, fir, pine, larch, hemlock and cypress.

Click on the image for a larger picture. Paleobotany and paleoentomology adventurers at an insect and plant locality in the upper Eocene Chicken Creek Formation, Bull Run, Nevada. The view looks northward from the 37 million-year-old fossil-bearing site, which occurs in the pale-greenish to tan shales that erode from the roadcut. Here can be found rather common fly larvae exoskeletons, probably similar to specimens that occur in the famous Eocene Green River Formation of Wyoming, eastern Utah and Colorado--in addition to conifer winged seeds.

Click on the image for a larger picture. An enthusiast of paleobotany and paleoentomology inspects an insect and plant locality in the upper Eocene Chicken Creek Formation, Bull Run, Nevada. The view looks northward from the 37 million-year-old fossil-bearing site, which occurs in the pale-greenish to tan shales that erode from the roadcut. Here can be recovered rather common fly larvae exoskeletons, probably similar to specimens that occur in the famous Eocene Green River Formation of Wyoming, eastern Utah and Colorado--plus, conifer winged seeds.

Click on the image for a larger picture. A paleobotany and paleoentomology prospector at Bull Run Basin, Nevada, examines a piece of shale from the upper Eocene Chicken Creek Formation; it bears several insect insect larvae that resemble similar types sometimes observed in the Eocene Green River Formation of Wyoming, eastern Utah, and Colorado. The locality yields insect larvae and winged conifer seeds.

Images Of Fossil Plants And Insects

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Click on the image for a larger picture. Here is a winged seed (10 millimeters in actual length) from a spruce, which appears to most closely resemble a species the late paleobotanist Daniel I. Axelrod called Picea coloradensis, a fossil conifer that cannot be compared directly with any one living taxon, although it shows obvious relationships to two modern species--Picea pungens and Picea engelmannii, the Colorado Blue spruce and the Engelmann Spruce, respectively.

Click on the image for a larger picture. Here are seven conifer winged seeds, all collected in the Bull Bun district, Nevada, from the upper Eocene Chicken Creek Formation. For reference, the winged seed in the center is 10 millimeters in actual length. At lower right is an unspecified fir winged seed; at the upper left is a winged seed from an unspecified variety of pine. The remainder of the specimens belong to a species of spruce called scientifically Picea coloradensis, a fossil variety that shows affinities to both the modern Colorado Blue spruce and the Engelmann spruce.

Click on the image for a larger picture. Three insect fossils from the upper Eocene Chicken Creek Formation, collected from Bull Run Basin, Nevada; they appear to represent a variety of fly larvae perhaps similar to types sometimes noted in the world-famous Eocene Green River Formation of Colorado, eastern Utah, and Wyoming. The specimens are 8 millimeters long in actual dimension.

Click on the image for a larger picturel. Three small slabs of shale from the upper Eocene Chicken Creek Formation, Bull Run Basin, Nevada, bearing several dark-brownish, carbonized fossil fly larvae; none of the arthropods is longer than about eight millimeters..

Everyone's Invited To Visit My Other Web Sites

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Paleontology-Related Pages

Web sites I have created pertaining to fossils

  • Fossils In Death Valley National Park: A site dedicated to the paleontology, geology, and natural wonders of Death Valley National Park; lots of on-site photographs of scenic localities within the park; images of fossils specimens; links to many virtual field trips of fossil-bearing interest.
  • Fossil Insects And Vertebrates On The Mojave Desert, California: Journey to two world-famous fossil sites in the middle Miocene Barstow Formation: one locality yields upwards of 50 species of fully three-dimensional, silicified freshwater insects, arachnids, and crustaceans that can be dissolved free and intact from calcareous concretions; a second Barstow Formation district provides vertebrate paleontologists with one of the greatest concentrations of Miocene mammal fossils yet recovered from North America--it's the type locality for the Bartovian State of the Miocene Epoch, 15.9 to 12.5 million years ago, with which all geologically time-equivalent rocks in North American are compared.
  • A Visit To Fossil Valley, Great Basin Desert, Nevada: Take a virtual field trip to a Nevada locality that yields the most complete, diverse, fossil assemblage of terrestrial Miocene plants and animals known from North America--and perhaps the world, as well. Yields insects, leaves, seeds, conifer needles and twigs, flowering structures, pollens, petrified wood, diatoms, algal bodies, mammals, amphibians, reptiles, bird feathers, fish, gastropods, pelecypods (bivalves), and ostracods.
  • Fossils At Red Rock Canyon State Park, California: Visit wildly colorful Red Rock Canyon State Park on California's northern Mojave Desert, approximately 130 miles north of Los Angeles--scene of innumerable Hollywood film productions and commercials over the years--where the Middle to Late Miocene (13 to 7 million years old) Dove Spring Formation, along with a classic deposit of petrified woods, yields one of the great terrestrial, land-deposited Miocene vertebrate fossil faunas in all the western United States.
  • Cambrian And Ordovician Fossils At Extinction Canyon, Nevada: Visit a site in Nevada's Great Basin Desert that yields locally common whole and mostly complete early Cambrian trilobites, in addition to other extinct organisms such as graptolites (early hemichordate), salterella (small conical critter placed in the phylum Agmata), Lidaconus (diminutive tusk-shaped shell of unestablished zoological affinity), Girvanella (photosynthesizing cyanobacterial algae), and Caryocaris (a bivalved crustacean).
  • Late Pennsylvanian Fossils In Kansas: Travel to the midwestern plains to discover the classic late Pennsylvanian fossil wealth of Kansas--abundant, supremely well-preserved associations of such invertebrate animals as brachiopods, bryozoans, corals, echinoderms, fusulinids, mollusks (gastropods, pelecypods, cephalopods, scaphopods), and sponges; one of the great places on the planet to find fossils some 307 to 299 million years old.
  • Fossil Plants Of The Ione Basin, California: Head to Amador County in the western foothills of California's Sierra Nevada to explore the fossil leaf-bearing Middle Eocene Ione Formation of the Ione Basin. This is a completely undescribed fossil flora from a geologically fascinating district that produces not only paleobotanically invaluable suites of fossil leaves, but also world-renowned commercial deposits of silica sand, high-grade kaolinite clay and the extraordinarily rare Montan Wax-rich lignites (a type of low grade coal).
  • Ice Age Fossils At Santa Barbara, California--Journey to the famed So Cal coastal community of Santa Barbara (about a 100 miles north of Los Angeles) to explore one of the best marine Pleistocene invertebrate fossil-bearing areas on the west coast of the United States; that's where the middle Pleistocene Santa Barbara Formation yields nearly 400 species of pelecypod bivalve mollusks, gastropods, chitons, scaphopods, pteropods, brachiopods, bryozoans, corals, ostracods (minute bivalve crustaceans), worm tubes, and foraminifers.
  • Trilobites In The Marble Mountains, Mojave Desert, California: Take a trip to the place that first inspired my life-long fascination and interest in fossils--the classic trilobite quarry in the Lower Cambrian Latham Shale, in the Marble Mountains of California's Mojave Desert. It's a special place, now included in the rather recently established Trilobite Wilderness, where some 21 species of ancient plants and animals have been found--including trilobites, an echinoderm, a coelenterate, mollusks, blue-green algae and brachiopods.
  • Fossil Plants In The Neighborhood Of Reno, Nevada: Visit two famous fossil plant localities in the Great Basin Desert near Reno, Nevada--a place to find leaves, seeds, needles, foilage, and cones in the middle Miocene Pyramid and Chloropagus Formations, 15.6 and 14.8 to 13.3 million years old, respectively.
  • Dinosaur-Age Fossil Leaves At Del Puerto Creek, California: Journey to the western edge of California's Great Central Valley to explore a classic fossil leaf locality in an upper Cretaceous section of the upper Cretaceous to Paleocene Moreno Formation; the plants you find there lived during the day of the dinosaur.
  • Early Cambrian Fossils Of Westgard Pass, California: Visit the Westgard Pass area, a world-renowned geologic wonderland several miles east of Big Pine, California, in the neighboring White-Inyo Mountains, to examine one of the best places in the world to find archaeocyathids--an enigmatic invertebrate animal that went extinct some 510 million years ago, never surviving past the early Cambrian; also present there in rocks over a half billion years old are locally common trilobites, plus annelid and arthropod trails, and early echinoderms.
  • Plant Fossils At The La Porte Hydraulic Gold Mine, California: Journey to a long-abandoned hydraulic gold mine in the neighborhood of La Porte, northern Sierra Nevada, California, to explore the upper Eocene La Porte Tuff, which yields some 43 species of Cenozoic plants, mainly a bounty of beautifully preserved leaves 34.2 million years old.
  • A Visit To Ammonite Canyon, Nevada: Explore one of the best-exposed, most complete fossiliferous marine late Triassic through early Jurassic geologic sections in the world--a place where the important end-time Triassic mass extinction has been preserved in the paleontological record. Lots of key species of ammonites, brachiopods, corals, gastropods and pelecypods.
  • Fossil Plants At The Chalk Bluff Hydraulic Gold Mine, California: Take a field trip to the Chalk Bluff hydraulic gold mine, western foothills of California's Sierra Nevada, for leaves, seeds, flowering structures, and petrified wood from some 70 species of middle Eocene plants.
  • Field Trip To The Alexander Hills Fossil District, Mojave Desert, California: Visit a locality outside the southern sector of Death Valley National Park to explore a paleontological wonderland that produces: Precambrian stromatolites over a billion years old; early skeletonized eukaryotic cells of testate amoebae over three-quarters of billion years old; early Cambrian trilobites, archaeocyathids, annelid trails, arthropod tracks, and echinoderm material; Pliocene-Pleistocene vertebrate and invertebrate faunas; and late middle Miocene camel tracks, petrified palm wood, petrified dicotlyedon wood, and permineralized grasses.
  • Fossils In Millard County, Utah: Take virtual field trips to two world-famous fossil localities in Millard County, Utah--Wheeler Amphitheater in the trilobite-bearing middle Cambrian Wheeler Shale; and Fossil Mountain in the brachiopod-ostracod-gastropod-echinoderm-trilobite rich lower Ordovician Pogonip Group.
  • Fossil Plants, Insects And Frogs In The Vicinity Of Virginia City, Nevada: Journey to a western Nevada badlands district near Virginia City and the Comstock Lode to discover a bonanza of paleontology in the late middle Miocene Coal Valley Formation.
  • Paleozoic Era Fossils At Mazourka Canyon, Inyo County, California: Visit a productive Paleozoic Era fossil-bearing area near Independence, California--along the east side of California's Owens Valley, with the great Sierra Nevada as a dramatic backdrop--a paleontologically fascinating place that yields a great assortment of invertebrate animals.
  • Late Triassic Ichthyosaur And Invertebrate Fossils In Nevada: Journey to two classic, world-famous fossil localities in the Upper Triassic Luning Formation of Nevada--Berlin-Ichthyosaur State Park and Coral Reef Canyon. At Berlin-Ichthyosaur, observe in-situ the remains of several gigantic ichthyosaur skeletons preserved in a fossil quarry; then head out into the hills, outside the state park, to find plentiful pelecypods, gastropods, brachiopods and ammonoids. At Coral Reef Canyon, find an amazing abundance of corals, sponges, brachiopods, echinoids (sea urchins), pelecypods, gastropods, belemnites and ammonoids.
  • Fossils From The Kettleman Hills, California: Visit one of California's premiere Pliocene-age (approximately 4.5 to 2.0 million years old) fossil localities--the Kettleman Hills, which lie along the western edge of California's Great Central Valley northwest of Bakersfield. This is where innumerable sand dollars, pectens, oysters, gastropods, "bulbous fish growths" and pelecypods occur in the Etchegoin, San Joaquin and Tulare Formations.
  • Field Trip To The Kettleman Hills Fossil District, California: Take a virtual field trip to a classic site on the western side of California's Great Central Valley, roughly 80 miles northwest of Bakersfield, where several Pliocene-age (roughly 4.5 to 2 million years old) geologic rock formations yield a wealth of diverse, abundant fossil material--sand dollars, scallop shells, oysters, gastropods and "bulbous fish growths" (fossil bony tumors--found nowhere else, save the Kettleman Hills), among many other paleontological remains.
  • A Visit To The Sharktooth Hill Bone Bed, Southern California: Travel to the dusty hills near Bakersfield, California, along the eastern side of the Great Central Valley in the western foothills of the Sierra Nevada, to explore the world-famous Sharktooth Hill Bone Bed, a Middle Miocene marine deposit some 16 to 15 million years old that yields over a hundred species of sharks, rays, bony fishes, and sea mammals from a geologic rock formation called the Round Mountain Silt Member of the Temblor Formation; this is the most prolific marine, vertebrate fossil-bearing Middle Miocene deposit in the world.
  • High Sierra Nevada Fossil Plants, Alpine County, California: Visit a remote fossil leaf and petrified wood locality in the Sierra Nevada, at an altitude over 8,600 feet, slightly above the local timberline, to find 7 million year-old specimens of cypress, Douglas-fir, White fir, evergreen live oak, and giant sequoia, among others.
  • In Search Of Fossils In The Tin Mountain Limestone, California: Journey to the Death Valley area of Inyo County, California, to explore the highly fossiliferous Lower Mississippian Tin Mountain Limestone; visit three localities that provide easy access to a roughly 358 million year-old calcium carbate accumulation that contains well preserved corals, brachiopods, bryozoans, crinoids, and ostracods--among other major groups of invertebrate animals.
  • Middle Triassic Ammonoids From Nevada: Travel to a world-famous fossil locality in the Great Basin Desert of Nevada, a specific place that yields some 41 species of ammonoids, in addition to five species of pelecypods and four varieties of belemnites from the Middle Triassic Prida Formation, which is roughly 235 million years old; many paleontologists consider this specific site the single best Middle Triassic, late Anisian Stage ammonoid locality in the world. All told, the Prida Formation yields 68 species of ammonoids spanning the entire Middle Triassic age, or roughly 241 to 227 million years ago.
  • Late Miocene Fossil Leaves At Verdi, Washoe County, Nevada: Explore a fascinating fossil leaf locality not far from Reno, Nevada; find 18 species of plants that prove that 5.8 million years ago this part of the western Great Basin Desert would have resembled, floristically, California's lush green Gold Country, from Placerville south to Jackson.
  • Fossils Along The Loneliest Road In America: Investigate the extraordinary fossil wealth along some 230 miles of The Loneliest Road In America--US Highway 50 from the vicinity of Eureka, Nevada, to Delta in Millard County, Utah. Includes on-site images and photographs of representative fossils (with detailed explanatory text captions) from every geologic rock deposit I have personally explored in the neighborhood of that stretch of Great Basin asphalt. The paleontologic material ranges in geologic age from the middle Eocene (about 48 million years ago) to middle Cambrian (approximately 505 million years old).
  • Fossil Bones In The Coso Range, Inyo County, California: Visit the Coso Range Wilderness, west of Death Valley National Park at the southern end of California's Owens Valley, where vertebrate fossils some 4.8 to 3.0 million years old can be observed in the Pliocene-age Coso Formation: It's a paleontologically significant place that yields many species of mammals, including the remains of Equus simplicidens, the Hagerman Horse, named for its spectacular occurrences at Hagerman Fossil Beds National Monument in Idaho; Equus simplicidens is considered the earliest known member of the genus Equus, which includes the modern horse and all other equids.
  • Field Trip To A Vertebrate Fossil Locality In The Coso Range, California: Take a cyber-visit to the famous bone-bearing Pliocene Coso Formation, Coso Mountains, Inyo County, California; includes detailed text for the field trip, plus on-site images and photographs of vertebrate fossils.
  • Fossil Plants At Aldrich Hill, Western Nevada: Take a field trip to western Nevada, in the vicinity of Yerington, to famous Aldrich Hill, where one can collect some 35 species of ancient plants--leaves, seeds and twigs--from the Middle Miocene Aldirch Station Formation, roughly 12 to 13 million years old. Find the leaves of evergreen live oak, willow, and Catalina Ironwood (which today is restricted in its natural habitat solely to the Channel Islands off the coast of Southern California), among others, plus the seeds of many kinds of conifers, including spruce; expect to find the twigs of Giant Sequoias, too.
  • Fossils From Pleistocene Lake Manix, California: Explore the badlands of the Manix Lake Beds on California's Mojave Desert, an Upper Pleistocene deposit that produces abundant fossil remains from the silts and sands left behind by a great fresh water lake, roughly 350,000 to 19,000 years old--the Manix Beds yield many species of fresh water mollusks (gastropods and pelecypods), skeletal elements from fish (the Tui Mojave Chub and Three-Spine Stickleback), plus roughly 50 species of mammals and birds, many of which can also be found in the incredible, world-famous La Brea Tar Pits of Los Angeles.
  • Field Trip To Pleistocene Lake Manix, California: Go on a virtual field trip to the classic, fossiliferous badlands carved in the Upper Pleistocene Manix Formation, Mojave Desert, California. It's a special place that yields beaucoup fossil remains, including fresh water mollusks, fish (the Mojave Tui Chub), birds and mammals.
  • Trilobites In The Nopah Range, Inyo County, California: Travel to a locality well outside the boundaries of Death Valley National Park to collect trilobites in the Lower Cambrian Pyramid Shale Member of the Carrara Formation.
  • Ammonoids At Union Wash, California: Explore ammonoid-rich Union Wash near Lone Pine, California, in the shadows of Mount Whitney, the highest point in the contiguous United States. Union Wash is a ne plus ultra place to find Early Triassic ammonoids in California. The extinct cephalopods occur in abundance in the Lower Triassic Union Wash Formation, with the dramatic back-drop of the glacier-gouged Sierra Nevada skyline in view to the immediate west.
  • A Visit To The Fossil Beds At Union Wash, Inyo County California: A virtual field trip to the fabulous ammonoid accumulations in the Lower Triassic Union Wash Formation, Inyo County, California--situated in the shadows of Mount Whitney, the highest point in the contiguous United States.
  • Ordovician Fossils At The Great Beatty Mudmound, Nevada: Visit a classic 475-million-year-old fossil locality in the vicinity of Beatty, Nevada, only a few miles east of Death Valley National Park; here, the fossils occur in the Middle Ordovician Antelope Valley Limestone at a prominent Mudmound/Biohern. Lots of fossils can be found there, including silicified brachiopods, trilobites, nautiloids, echinoderms, bryozoans, ostracodes and conodonts.
  • Paleobotanical Field Trip To The Sailor Flat Hydraulic Gold Mine, California: Journey on a day of paleobotanical discovery with the FarWest Science Foundation to the western foothills of the Sierra Nevada--to famous Sailor Flat, an abandoned hydraulic gold mine of the mid to late 1800s, where members of the foundation collect fossil leaves from the "chocolate" shales of the Middle Eocene auriferous gravels; all significant specimens go to the archival paleobotanical collections at the University California Museum Of Paleontology in Berkeley.
  • Early Cambrian Fossils In Western Nevada: Explore a 518-million-year-old fossil locality several miles north of Death Valley National Park, in Esmeralda County, Nevada, where the Lower Cambrian Harkless Formation yields the largest single assemblage of Early Cambrian trilobites yet described from a specific fossil locality in North America; the locality also yields archeocyathids (an extinct sponge), plus salterella (the "ice-cream cone fossil"--an extinct conical animal placed into its own unique phylum, called Agmata), brachiopods and invertebrate tracks and trails.
  • Fossil Leaves And Seeds In West-Central Nevada: Take a field trip to the Middlegate Hills area in west-central Nevada. It's a place where the Middle Miocene Middlegate Formation provides paleobotany enthusiasts with some 64 species of fossil plant remains, including the leaves of evergreen live oak, tanbark oak, bigleaf maple, and paper birch--plus the twigs of giant sequoias and the winged seeds from a spruce.
  • Ordovician Fossils In The Toquima Range, Nevada: Explore the Toquima Range in central Nevada--a locality that yields abundant graptolites in the Lower to Middle Ordovician Vinini Formation, plus a diverse fauna of brachiopods, sponges, bryozoans, echinoderms and ostracodes from the Middle Ordovician Antelope Valley Limestone.
  • Fossil Plants In The Dead Camel Range, Nevada: Visit a remote site in the vicinity of Fallon, Nevada, where the Middle Miocene Desert Peak Formation provides paleobotany enthusiasts with 22 species of nicely preserved leaves from a variety of deciduous trees and evergreen live oaks, in addition to samaras (winged seeds), needles and twigs from several types of conifers.
  • Early Triassic Ammonoid Fossils In Nevada: Visit the two remote localities in Nevada that yield abundant, well-preserved ammonoids in the Lower Triassic Thaynes Formation, some 240 million years old--one of the sites just happens to be the single finest Early Triassic ammonoid locality in North America.
  • Fossil Plants At Buffalo Canyon, Nevada: Explore the wilds of west-central Nevada, a number of miles from Fallon, where the Middle Miocene Buffalo Canyon Formation yields to seekers of paleontology some 54 species of deciduous and coniferous varieties of 15-million-year-old leaves, seeds and twigs from such varieties as spruce, fir, pine, ash, maple, zelkova, willow and evergreen live oak
  • High Inyo Mountains Fossils, California: Take a ride to the crest of the High Inyo Mountains to find abundant ammonoids and pelecypods--plus, some shark teeth and terrestrial plants in the Upper Mississippian Chainman Shale, roughly 325 million years old.
  • Field Trip To The Copper Basin Fossil Flora, Nevada: Visit a remote region in Nevada, where the Late Eocene Dead Horse Tuff provides seekers of paleobotany with some 42 species of ancient plants, roughly 39 to 40 million years old, including the leaves of alder, tanbark oak, Oregon grape and sassafras.
  • Fossil Plants And Insects At Bull Run, Nevada: Head into the deep backcountry of Nevada to collect fossils from the famous Late Eocene Chicken Creek Formation, which yields, in addition to abundant fossil fly larvae, a paleobotanically wonderful association of winged seeds and fascicles (bundles of needles) from many species of conifers, including fir, pine, spruce, larch, hemlock and cypress. The plants are some 37 million old and represent an essentially pure montane conifer forest, one of the very few such fossil occurrences in the Tertiary Period of the United States.
  • A Visit To The Early Cambrian Waucoba Spring Geologic Section, California: Journey to the northwestern sector of Death Valley National Park to explore the classic, world-famous Waucoba Spring Early Cambrian geologic section, first described by the pioneering paleontologist C.D. Walcott in the late 1800s; surprisingly well preserved 540-510 million-year-old remains of trilobites, invertebrate tracks and trails, Girvanella algal oncolites and archeocyathids (an extinct variety of sponge) can be observed in situ.
  • Petrified Wood From The Shinarump Conglomerate: An image of a chunk of petrified wood I collected from the Upper Triassic Shinarump Conglomerate, outside of Dinosaur National Monument, Colorado.
  • Fossil Giant Sequoia Foliage From Nevada: Images of the youngest fossil foliage from a giant sequoia ever discovered in the geologic record--the specimen is Lower Pliocene in geologic age, around 5 million years old.
  • Some Favorite Fossil Brachiopods Of Mine: Images of several fossil brachiopods I have collected over the years from Paleozoic, Mesozoic and Cenozoic-age rocks.
  • In Search Of Vanished Ages--Field Trips To Fossil Localities In California, Nevada, And Utah--My fossils-related field trips in full print book form (pdf). 98,703 words (equivalent to a medium-size hard cover work of non-fiction); 250 printed pages (equivalent to about 380 pages in hard cover book form); 27 chapters; 30 individual field trips to places of paleontological interest; 60 photographs--representative on-site images and pictures of fossils from each locality visited.

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