Fossils and Artifacts: Intriguing Legacies
by Les Davis
Prologue
His long, cautious stalk at an end, the Hunter waited impatiently for the browsing Apatosaurus (Brontosaurus) ahead of him to turn in the opposite direction. When the animal's searching head finally swiveled, snakelike, away from the Hunter, he reared back and hurled his heavy spear at the underbelly of the huge creature. But, when the stone-tipped spear slammed harmlessly against its iron-hard skin, the great beast didn't flinch. The fire-hardened wooden shaft shattered upon impact, its splinters flying off into the forest twilight. At first stunned by the puniness of the spear, the Hunter was astonished and then terrified as he saw the animal's tiny yet awesome head looking curiously down and sniffing at him. The dinosaur seemed to wonder about this fragile, two-legged, hairless, smelly thing that had interrupted its repose. The chagrined Hunter, humiliated and pathetic against this seemingly easy prey, fled silently into the waiting forest. Discouraged at his failure to obtain food essential for his hungry brood, the Hunter worried that, at this rate, his race might be doomed, its extinction inevitable--and imminent!
What is wrong with this seductive and compelling yet entirely absurd anecdote?
The real dinosaur-humankind connection
The foregoing intriguing, but false popular-culture scenario is nonsensical---it denies the scientific fact that dinosaurs and humans did not coexist in time or space. That the Hominids, that is, the australopithecines and members of the genus Australopithecus and the genus Homo, such as H. habilis (and later H. erectus and H. sapiens neanderthalensis), evolved on Earth only four million years ago is accepted as fact. By 3.2 million years ago, "Lucy" (or should it be "Larry") was walking upright on her (possibly his) hindlegs in Africa.
Anatomically modern humans (H. sapiens sapiens) evolved much later. They were likely established in the Near East by at least 100,000 years ago during the Upper Cenozoic Era, some 65 million years after dinosaurs had disappeared, by the end of the Lower Cenozoic Era, from the face of the Earth. Fully evolved H. sapiens sapiens expanded out of northeastern Siberia into humanly unoccupied North America only recently, probably within the last 30,000 to 20,000 years or so, during the Upper Pleistocene Ice Age. We continue to live in an Ice-Age world today, albeit during a relatively warm and dry interval between glaciations.
The sheer folly of thinking (and believing) in these informed times that dinosaurs lived alongside and interacted in any way with modern forms of humans may be its own just punishment!
Back to the point: dinosaurs rather than humans experienced extinction, wiped out as they were by a catastrophic asteroid strike, by choking volcanic ash, or as a result of more gradual climatic, environmental, or biological forces that had become irresistible by 65 million years ago.
Clearly, the wholesale public rejection of the dinosaur-human coexistence notion has been hampered by the swarm of popular fantasies marketed to American audiences relentlessly by writers, artists, cartoonists, and filmmakers. Among such creations, "Alley Oop," "The Flintstones," "B. C.," and Tarzan the Terrible come easily to mind.
The scientific division of labor: what's in a name?
Although the specialized languages of science can be intimidating and downright meaningless to nonspecialists, such languages were developed to achieve clarity, to standardize meaning, and to facilitate the work of scientists. Some simplified definitions may be useful translations of some basic terms and concepts.
Geology is the science that studies the Earth in general, the crust and the rock layers or strata that derive from its formation, composition, and weathering. Stratification refers to the process and stratigraphy to the result of Earth formation and change. Biological and cultural remains that occur within a single layer or stratum are approximately the same age as that stratum unless eroded from earlier sediments and mixed together. Geofacts are rocks in their natural state, unmodified and unused by humans, some of which may take on the appearance of artifacts.
Paleontology is that division of Geology or Biology which studies fossil animals and plants; it often refers to extinct species. Fossils are the natural or mineralized remains of organisms from former geological periods.
Archaeology is the subfield within the discipline of Anthropology that studies the origin, development, adaptations, and behavior of once-living peoples. Prehistoric archaeologists recover and study material remains from those cultural events and developments that transpired prior to the advent of literate observers. Historical archaeologists employ the data-recovery techniques of archaeology in order to investigate documented historic events. Artifacts include tools, objects, and structures made by humans who relied on raw materials found in nature to satisfy a wide range of culturally defined needs.
Antiquity refers to ancient times (prehistoric and historic) within the human experience. The Greek prefix palaeo-, which is anglicized in both paleontology and Paleoindian (archaeology), refers to ancient, long ago, involving or dealing with ancient forms. The prefix archaeo-, when joined with the suffix -logy (the study of), refers to the study of the primitive, the beginning, antiquity, and ancient history, or the science of archaeology. The Latin term archaeologia refers to the study of antiquity.
The term prehistoric, as used by archaeologists, refers to human events that preceded the invention of writing. The advent of writing about 5,000 years ago in Egypt marks the beginning of historic times. The popular use of prehistoric, as in "Prehistoric Dinosaurs," from which it might reasonably be inferred that "Historic Dinosaurs" also existed, is misleading. Because prehistoric refers generally to the period of human prehistory, archaeologists prefer to regard the time of the dinosaurs as a period within the remote geological past, rather than within the prehistoric past. The long span of time between dinosaur extinction and the emergence of humankind sustains that usage. Prehistoric archaeology is the study of artifacts and associated remains of particular human groups.
Those definitions distinguish the practice of vertebrate paleontology from that of prehistoric archaeology. The common denominator that appears to link these disciplines is that both are interested in the past and in bones. The nature and relative antiquity of the biological remains studied by each discipline provide essential clues to different technical orientations. Paleontologists do not dig up bones: they recover fossils (mineralized substitutes for the original bones), teeth, shells, and plants. The mineralized, or fossilized, version, which is actually stone, is distinguishable from the encasing rock formation by its appearance and form. Tracks and imprints of skin and gut, and mineralized dung, are of considerable interest to paleontologists because dinosaur biology and behavior are inferred from that evidence.
In the realm of prehistoric archaeology, it is possible, but unlikely, that Late Quaternary Period lifeforms contemporary with early Native Americans may have become mineralized (fossilized) over a few thousand years. Remains of fossil species are of interest to vertebrate paleontologists and to archaeologists (especially to Human Paleontologists), but for different reasons. Because human and other skeletal remains that survive from the Recent Epoch are seldom fossilized, and thus retain the datable organic fraction, the age of their demise can be determined by radiocarbon dating. This method, which measures time elapsed since death as far back in time as 50,000 years ago, is invaluable to archaeologists and other Late Quaternary Period life scientists because it provides temporally valid, reproducible age-dating results by instrumental means; the uncertainty associated with these dates is on the order of ± 60 to 2,000 years depending on age. Potassium-argon dating is used to establish the ages of geological strata that contain dinosaurs and also Plio-Pleistocene strata with early Ice-Age hominid-bearing strata, such as those at Olduvai Gorge in Africa. In that case, statistical uncertainty is measured in hundreds of thousands of years.
Comic art has lightened the American spirit for at least eight decades in usually heartwarming, harmless make-believe, as in "The Foolish Dinosaur Fiasco," "Danny and the Dinosaur," "Gertie the Dinosaur," and "The Dinosaur and the Missing Link," ridiculous situations into which humans were often boldly, if unwisely, written. Cinematic treatments of Lost Worlds rediscovered, such as "1,000,000 B.C." (featuring Raquel Welch), with extinct species and other-worldly monsters of the imagination such as King Kong and Godzilla, have fascinated, entertained, and misled audiences about the reality of dinosaur/monster/human coexistence.
One does not wish to suggest, however, that humans and dinosaurs are not somehow connected: after all, they are both vertebrates! Vertebrate paleontologists still hunt dinosaurs today, but they expect to bag only the fossilized remains of dinosaurs long-since entombed in rocky crypts. Dinosaur remains must be exhumed by excavation in order that their habitat, biology, and behavior can be inferred through painstaking study.
Dinosaur fossils and prehistoric artifacts (the latter the durable residues of now-extinct human behaviors) attract the attention of many citizens who visit and wander the vast, open, and remote landscapes of Montana today. That fossils and artifacts found in our backyards are regarded by some as collectible, possessable, ownable relics is no surprise. Uncounted numbers of these articles are picked up as curiosities, taken home, wondered about, and occasionally brought to the attention of interested researchers.
The place and roles of museums
Museum staff members sometimes become uneasy when enthusiasts bring mystery objects to them expecting quick identification and interpretation. Part of the confusion lies in the meaning of languages that specialists use to classify and assign diverse objects to specific fields of study. For instance, objects shown to archaeologists as "artifacts" may actually not beartifacts (objects of human manufacture and use of interest to archaeologists). Instead, they are often geofacts (rocks that appear to have been modified by humans, but were not and are mostly of interest to geologists) or fossils (bones, teeth, footprints, and other residues of interest to vertebrate or invertebrate paleontologists). Paleontologists are sometimes asked to take a look at artifacts by finders who think that paleontologists study the tools of prehistoric peoples. Archaeologists, to whom artifacts are bread and butter, are not ordinarily interested in the fossilized remains of species that lived and died prior to the tenure of humans on Earth. Fossils and artifacts, when taken to geologists for identification, should have been referred instead to paleontologists or archaeologists for information.
People who take "mystery" objects or "treasures" to museum staff members for identification sometimes get what may seem to them to be the "runaround" when they try to learn about objects they have found. Such invaluable curiosity may be diminished by the daunting maze they must negotiate to find the appropriate specialist, if indeed one exists. Rare opportunities for researchers to examine potentially interesting fossils and artifacts can be so easily forfeited when disappointed collectors feel thwarted. Such unnecessary lost opportunities can be tragic in an enormous place like Montana where so few specialists are available in public institutions.
In reality, given its vastness, few Montana backyards have been surveyed by research paleontologists and archaeologists. By contrast, many knowledgeable, naturally inquisitive, alert people gain access to large expanses of land that include fossils and artifacts. Contributions made by amateur paleontologists and archaeologists to the sciences are considerable and valuable. For example, many articles in Archaeology in Montana (published by the Montana Archaeological Society) have been authored by amateur archaeologists. The 1990 recovery of a 90-percent complete Tyrannosaurus rex (end of the Late Cretaceous Age, 68-65 million years ago) from federal land in eastern Montana by the Museum of the Rockies resulted from an amateur referral. The discovery and recovery of the Lindsay Mammoth from a county road right-of-way in eastern Montana followed a similar pattern.
To some people, the fundamental differences (and interplay) between and among scientific fields of inquiry such as paleontology and archaeology are unknown. Newspaper releases such as the following tend to further complicate those essential distinctions: "The [Museum of the Rockies'] display will include a 23-foot adult Maiasaura [Late Cretaceous Age: 80 million years old] skeleton, a nest with 14 baby Maia [dinosaur] skeletons, five 16-foot [dinosaur] juveniles, and various other displays. All the fossils were collected from Cut Bank and Choteau archaeological [should instead read paleontological] sites in Montana [my emphasis and inserts]." Elsewhere, the statement, "When archaeologists [should read paleontologists] realized that the brontosaurus was actually an erroneously fictitious dinosaur...," repeated the same error. Newspapers and other news-reporting media are expected to inform readers accurately about basic science matters, even if reporters only give the appearance of being knowledgeable about such matters. Failure to inform the interested public accurately can deepen public misunderstandings about the practice, products, and value of science.
Multidisciplinary research, prompted by the discovery and recovery of the Lindsay Mammoth in east-central Montana, illustrates how research specialists cooperate to reveal, describe, and explain the past. In this instance, erosion opened a revealing window into the past. An alert farmer, Joe Walker, passing along the road on his combine, looked through that window at something that caught his attention. He took appropriate action by referring his find to Dawson County officials.
Resurrecting the Lindsay Mammoth
Revealed through excavation and research, a nearly complete skeleton of a Columbian mammoth (Mammuthus columbi) was discovered in 1966 near the townsite of Lindsay, northwest of Glendive. The find was reported by Mr. Walker through a Dawson County commissioner, Don Gibson, to Montana State University. A paleontologist and an archaeologist visited the location that same year to determine the find's nature and possible significance. A buried mammoth skeleton with what appeared to be stone flakes in the vicinity led to an investigation in 1967, in cooperation with Dawson County officials. (The stone flakes observed on the roadway, which had excited the possibility that this might be an Ice-Age Paleoindian mammoth kill site, turned out to be crushed agate used by the county to gravel the road.) The genus and species of the mammoth were determined by a vertebrate paleontologist following recovery of the skeletal remains. Based on molar teeth eruption, the paleontologist concluded that this was a mature bull mammoth around 45 years of age, give or take a few years, that was in his prime at time of death. This bull stood more than 14 ft tall in life from ground level to the top of his skull!
A New World Late Pleistocene Epoch Ice-Age mammoth species, this Columbian mammoth bull had perished on the downwind side of a hill in rolling plains terrain about 11,500 years ago, as determined by radiocarbon dating. The Lindsay Mammoth is a member of a fossil species because that genus became extinct in the Americas around 10,000 years ago. Yet, neither the skeleton nor the once-attached, 9-foot tusks and molars had become fossilized: they survived into our time as bone, ivory, and enamel. Although the organic part of some skeletal elements had been leached somewhat, mineralization of the organic fraction was little advanced. The tusk ivory had become chalky, but retained its original structure and form. Thus, the skeletons of all fossil species are not necessarily fossilized. Factors such as burial circumstances can influence rates of fossilization, as well as preservation or decomposition.
That this mammoth had expired on a surface consisting of once-air-borne silt and sand is of interest to both geologists and soil scientists. These tiny windblown sediments originated from bedrock scoured by Continental ice sheets that had advanced southward into northern Montana from Canada thousands of years previously. Progressive warming and glacial ice melt led to the formation of extensive glacial lakes south of the ice front. Following the drying of these lakes, tons of fine-grained sediment (silt) that had accumulated in the lake beds were scoured and lifted by wind into the upper atmosphere. These fine particles later settled on and covered landscapes downwind. Silt continued to accumulate during the life and after the death of the Lindsay Mammoth, burying its remains beneath 4 ft of silt. There the carcass had lain undisturbed until erosion from a flashflood exposed its buried skeleton beneath a county road and adjacent borrow pit.
This remarkably well-preserved fossil mammoth is of interest to archaeologists bcause this large mammal lived, died, and became extinct during times when early hunter-gatherers in North America, known as Paleoindians, were frequenting the Northern Plains. The deathbed was excavated using archaeological techniques because of the possibility that stone flakes found on the roadway overlying the deathbed might have been produced by big-game hunters who had killed the mammoth and/or had utilized its carcass. The taphonomy (the study of deterioration and redistribution of skeletal parts and the associated natural processes) of the skeleton suggested the "unnatural" or artificial rearrangement (by human agency) of certain parts. There was evidence of the destruction of the upper skull and the hinge of the lower jaw and the intentional breakage and opening of marrow-bearing shoulder bones. Such anomalies are reminiscent of mammoth carcasses scavenged by early hunter-gatherers elsewhere in the Americas. The fact that none of the bone shatter from the breakage of these bones was found during excavation suggests that people and/or carnivores might have consumed or otherwise removed them from the immediate death vicinity.
Eight fragments of Fort Union Formation sandstone, derived from a locally exposed series of geological strata of Paleocene age, were found beneath the spinal column, beneath and alongside the "battered" front shoulder bones, beneath one tusk, and beneath and touching the damaged lower jaw. These stones and skeletal elements all occurred within the silt, the same stratigraphic unit, and are, therefore, likely the same age. While these fragments lack definite marks imposed by human use, and are, therefore, geofacts, all had been deposited adjacent to the evidently battered, broken-open limb bones. The sandstone fragments are thus regarded as manuports, stones carried by people into the deathbed situation for some reason. (Even the cyclonic windstorms and tornados that occasionally afflict modern Dawson County would not have caused these different stones, which together weigh 9.9 lbs., to have become airborne and transported and deposited on what would become a mammoth deathbed!)
Although the cause of the mammoth's death is not known, the lower face below the trunk had sustained a blow that had dislodged and scattered teeth (dental plates) at various distances from the final resting place of the jaw. This animal may have been mortally injured or incapacitated in combat with another mammoth or, less likely, by large predators because no gnawing marks were evident on the well-preserved surface of the bones. Nor would carnivore activity have resulted in the anomalous arrangement of skeletal parts within the deathbed. The possibility that Paleoindians had scavenged that carcass cannot be ruled out.
This case study illustrates the distinctions made between geofacts and artifacts, in the process revealing how scholars from interrelatable natural and cultural history research fields can cooperate in multidisciplinary research. Continue to the next page, Chasing Mammoth and Fossil Bison: The Hunt Continues.
Back to Geology Home Page.