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_{The Permian and I}

Midpoint

20 long hours out of Chicago and New York, I was dozing to the drone of the motors of the KLM DC 6. The Captain broke in, "We will be landing in Moscow in 25 minutes." "What on earth am I doing here?" flashed through my half-awake mind. Ahead was the formidable Russian city of Moscow, behind was a comfortable house, my wife and children worrying about me, a good profession and colleagues.

This was May 16th, 1959. The Soviet Union had a hostile image. But coming to Moscow had seemed to me the way to cap my work on ancient reptiles and amphibians, by comparing the ancient Permian fossils of North America and those of the western flanks of the Ural Mountains of Europe. The Paleontological Museum in Moscow was the magnet, but now that the city and museum were looming ahead and I was travel-weary, 1 approached them with some trepidation.

We did land, but not before the pilot had said, "Well, there it is, folks, that's where you will stay," as if somehow he was glad he would not be there long. The city from 5000 feet loomed a misty brown, outlined by dim lights. Once on the ground, we stopped in a light rain some distance from the reception area. My companions in flight, a group of 13 British automation experts, deplaned and were met with hugs and kisses from the Russians. I was met at the door of the plane by a military man who took my passport and said brusquely, in Russian, "Let's go." The British 13 formed a chattering procession with their friends, and I, with my militia man, a sober tandem group of two.

At the dimly lit reception desk the clerk took my credentials and was looking them over when I said, in what I hoped was Russian, "I am Professor Olson, from Chicago. "Over my shoulder came a voice in English, "And I am Professor Orlov, from Moscow." The nicest words I have ever heard! He said something to the clerk in Russian, and to me, "Let's have a beer." We did, and then departed for the Hotel Ukraine (Gastinitza Ukraina) in the Paleontological Institute's car. Professor Orlov was the head of the museum and its only Academician at that time. He took me to the 30th floor of the hotel and, after bacon and eggs at 2:30 A.M., I found my room and crawled in between the heavy Russian "comforters".

Thus began one of the most pleasant and productive times I have ever had while visiting a museum for study purposes. 1 didn't know then that this was to be but the first of seven visits or that I would find the wealth of Permian fossils which so neatly complemented those we had been finding in the middle part of the Permian of North America. The foundations for the study had been laid in research which started in 1935 in the earlier Permian beds of north central Texas. Moscow proved to be a major turning point in my investigations of the fossils as well as how I looked at the worlds of the both Permian and today.

Beginnings

The turbulent Permian period of geological time ended in massive extinctions of life on the land and in the seas. Long ago, beginning some 280 million years ago and lasting for about 50 million years, a vast single ocean and one massive continent set the stage for the final act of the evolutionary drama of the Paleozoic era. Some animals and plants did survive the early holocaust and some became our ancient ancestors. How this all came about, what it means, and forays into the special realms of historical science, with the Permian at center stage, have been the focus of my lifelong researches. How I threaded my way along the twistings and turnings of a search for knowledge and the friends I met along the way are the subject of this narrative.

When I entered college in 1928, I had no idea that one day I would become a student of "old bones" — a vertebrate paleontologist. I didn't even know what one of that ilk was, for unlike the youngsters of today, we were not "dinosaur nuts." Nor did I dream that a pair of cowboys, Texas villagers and ranchers, and a Russian writer and dreamer, Professor Ivan A. Efremov, would guide my pathways as I left my mentor, Professor Alfred S Romer, with a shiny new Ph.D. in 1935. Were it not for "old bones," the stimulation of the University of Chicago, and many friends and helpers my life would have turned out differently. The Permian just happened to be the time in which I landed.

I first saw the light of day on November 6,1910. A few years later I, like most children, became a bundle of curiosity and questions. Beyond pestering my parents with questions about the nature of the puzzling matter of time, my earliest "want to know" that I can recall led me to collect and crudely classify butterflies. It was in 1914 or 1915, in Berlin, Wisconsin, where my mother was tending her mother, who was ill, that I became fascinated by the big brown butterflies (monarchs) that perched on sunny days on red and yellow zinnias between my grand-parents' house and the home of Dr. Walbridge to the south. Along with the stately monarch, which could be picked off by hand, I managed to populate the screened porch with woolly bear caterpillars who wandered across the floor, sometimes getting squashed, and climbed the screens. The older people were tolerant.

For the next several years, until time for college, I kept at this hobby, and today, once again, my wife and I wander the world as amateur lepidopterists. With a close friend of my youth, Dudley Knox, I hunted the summer fields, collecting moths and butterflies, caterpillars for my menagerie, beetles, plants and anything else that piqued my curiosity about nature. In 1927, a trip to Florida with my co-collector Dudley capped this phase. I was 16 and he 15 as we took off in a 1921 Model T Ford, making about 150 miles a day. How our parents let us go remains a mystery to me.

My family lived then in Hinsdale, a small suburb of Chicago, in a big house with a big yard and barn. My father, Claire Myron Olson, was a dentist with a practice in Chicago and Hinsdale, and my mother, Aimee Hicks Olson, gave me and my older brother, Guindon Olson, a fine, comfortable and stable environment in which to grow up. We were very lucky in our parents. The years in Hinsdale were kindergarten, grade school and high school; piano, violin and piccolo lessons; athletics, first in the backyard and then high school football, basketball and track. At 5 feet 6 inches I was far from a power in contact sports but good enough to earn some letters. Grades were never much of a problem, mainly, as I recall, because I was scared of the teachers. I turned out to be valedictorian of my class in high school when the girl who should have been so honored ran off and got married just before graduation. This was taboo under the mores of the times.

We had some good and some poor teachers at Hinsdale Township High. One of the best, Mr. Brooks, introduced me to chemistry and for a while I thought I had found my academic niche. But another teacher, in mathematics, was not for me and he, along with my adviser, failed to tell me that my mathematics was insufficient not only for chemistry but for any branch of college science. I was really much better in Latin, and so took the University of Chicago scholarship examination in this field. The Virgil of the small town boy was no match for the Ovid of the intensely tutored students from the Chicago schools. But I was instead awarded a two-year athletic scholarship, an occasion for amusement later among my colleagues, many jaundiced with respect to college athletics. It so happened that gymnastics became my forte. I finally became quite good at bars, rings and mats. For two years I captained the team, and we won the Big Ten championships three years in a row. The University of Chicago was still a power in sports in the late 1920s and early 1930s, when athletics began to take a back seat to scholastic achievements. I amassed a nice batch of medals, the best being the Big Ten Athletic-Scholastic medal in my senior year. Phi Beta Kappa, into which I slipped by the barest margin, was the other side of the medal.

Disenchanted with chemistry after six or seven "memorization" courses, I switched to geology, drawn by the inspiration of Professor J Harlan Bretz. He was a hard headed Germanic professor who taught not by giving out information but by demanding reading and by challenging students in class, often bitterly and sarcastically. I loved to spar with him in class, rarely winning but always leaving with a desire to know more.

The later part of my undergraduate career, 1930-1932, merged with the depression of the 1930s. Things continued to worsen; as we entered graduate school on a shoestring, any thoughts my fellow students or I may have had earlier about the commercial value of a degree vanished. In a way this was good. Had I been thinking along such lines I never would have ended up in vertebrate paleontology. This esoteric study of extinct animals has rarely promised certain employment, let alone the possibility of wealth. It was education for education's sake, which is not all bad.

After receiving an S.B. degree in general geology and paleontology, I continued my education with work toward a master's degree in invertebrate paleontology under Professor Carey Croneis. This was in 1933 and things were tough financially. Many of us from the Department of Geology at the University of Chicago had found jobs at the Century of Progress — the 1933 Chicago World's Fair — aided by Professor Croneis, who was in charge of the Hall of Science. I was the partner of Llewelyn Price, another paleontology student, in an exhibit on evolution, which was manned seven hours a day, seven days a week, at $25 per week — a godsend.

Seeing no place to go during this time, I wrote some 50 letters to small colleges, telling them I could teach geology and "gym," then a compulsory subject. I received three replies and one solid offer!

Just as I was going to accept the offer, the Department of Geology gave me one of the four departmental fellowships. It covered tuition and left $250 to be spent anyway one wished, Unlike most fellowships today, this one required work. My duties in 1934 and 1935 consisted of reviewing books, and one of the odd results of this duty is that my most extensive annual list of publications is for 1935. The entries were neither the best nor the most significant, but they were plentiful. The editor of the Journal of Geology, which published the reviews, had great faith in me for he sent me books in French, German, Spanish and Italian, as well as English. As a result, I lost my fear of foreign languages as far as the written word was concerned.

The tedium of the summer's work at the World's Fair in 1933 was such that I felt I just couldn't stand another season of it. Lawn work at 25 cents per hour (35 cents for really hard jobs) and tutoring "any high school subject" at $1.00 per hour brought in enough cash to allow me to continue my education into 1935. By then I had switched over into vertebrate paleontology.

At the University of Chicago, in 1933, Professor Alfred S. Romer had initiated me into the marvels of Permian reptiles and amphibians. Romer was then following in the footsteps of such illustrious predecessors as professors Ermine C. Case and Samuel W. Williston, who studied the Permian before him. The wooden case drawers of the University of Chicago's Walker Museum were filled with unique collections of animals from the red beds of Texas, accumulated in large part by Paul C. Miller, Curator of Vertebrates in Walker Museum. With Romer and Miller and the outstanding collections, it was a heady introduction to the vertebrate paleontology of the Permian for a youngster of only 23.

What happened was this. Professor Romer — AI, and a close friend in later years — and I had come together in one of those odd ways that change careers. I had taken his course in Vertebrate Paleontology as a junior in college, and then strayed over into invertebrates. In 1933, when prohibition was on the way out, the Geological Society of America met at the University of Chicago. A big reception and smoker was held under Mitchell Towers. There were two punchbowls, one spiked with ersatz gin, the other pure. Good paleontologists never passed up a bit of stimulation, so by early evening both Romer and I found our inhibitions of student and faculty member relaxed. With my arm around his shoulder I slurred out that I thought I would take a research course with him. He slurred back, "Thash good." I did, and the switch was made.

I had just begun my studies of vertebrate animals under Professor Romer when, in 1934, he answered a call to Harvard and left me geographically alone, but at least under his remote guidance. About a year after this, the University of Chicago, with as much courage as good sense, but under urging from Romer, offered me the position of Instructor, to "fill" the shoes of my former mentor. I had just about completed my Ph.D. and was beginning to search for a job in those bleak times. Postdoctoral positions had not yet attained any prominence. The Department of Geology hurried me through my final degree requirements and Professor Romer did a massive job of revising my thesis. Then the University sent me on a six months tour of museums, universities and field localities, paying me a salary so I could afford to travel in my own Model A Ford. Once cast in this role, I was hooked, and my future was wedded to studies of the extinct animals of the Permian. Of course, it wasn't all straightforward.

When Professor Romer left for Harvard he borrowed a large suite of the Texas fossils in order to continue preparation of his monograph on Pelycosauria, primitive mammal-like reptiles. He left behind an important collection of later Permian fossils from the Karroo Desert of South Africa which included remains of advanced mammal-like reptiles, the Therapsida. Although my beginning field studies were in Texas, my early laboratory work was mainly devoted to the African materials that had been assembled some eight years before by Romer and Paul Miller. The happy result was that I developed an enduring interest in the evolution of the reptilian predecessors of the mammals and in the origin of our own ancestors. This interest motivated much of what I did thereafter.

The African materials, although from the Permian, were much younger than our Texas specimens and a major gap of several million years separated the evolutionary stages portrayed by these two collections. Collections in the Soviet Union partly, but not fully, filled this gap. As a result of language barriers and poor exchanges of information, we in the United States didn't know very much about the Russian specimens. Eventually this deficiency was remedied, but as I began my work on the African and Texas materials I had no idea that at some future time, all of the pieces would finally be brought together.

As time went by, and World War II was over, it became clear that if we ever were to relate the North American animals to those of the Soviet Union, and, through them, to the African materials, we must try to find fossils in America in beds that were higher and thus younger than any specimens so far known. With this need in mind, my parties and I pressed slowly into higher beds in Texas and then in Oklahoma, a venture in which we had considerable success.

This work in turn led to the development of my close scientific and personal relationship with Professor Ivan A. Efremov of Moscow, USSR. He, too, was interested in Permian life, and in our associations we found rapport in common ideas born in two highly diverse cultures. A substantial part of my narrative is devoted to our associations and their impacts on our common concerns about problems of science as well as society and philosophy, viewed from the perspectives of our mutual but often dissimilar interests in the intertwining lines of evolution and social development. But we both drew our major inspiration and sense of things from the rocks, times and animals of the 50 million years of Permian history. The reality and scope of such immense spans of time are the property of geologists, paleontologists and astronomers, and weave a peculiar bond in a world of thought incomprehensible to many in other fields.

The Permian

Permian times provide a common thread through all of this narrative and need some explaining. The Permian system and the place that it occupies in the calendar of geological history is shown in Figure 1. The relationships of the American, Russian and South African Permian include a minimum of detail necessary to make my remarks on the various subdivisions of time intelligible.

When I started exploring for Permian vertebrates in Texas, their fossils were known only from the lower beds, no higher than the Arroyo formation, the lowest rock unit of the Clear Fork group. These beds were first prospected in the late 1870s and extensive collections had been made and housed in many museums in the United States and abroad by the mid-1930s. But these activities took place long after the first remnants of vertebrates from the Permian were found in Russia. These date back to about 1780 and were unearthed by miners in their searches for copper. It was nearly 70 years later that the Permian was formally named. Some of the early specimens are still preserved, albeit in bad shape, in the Paleontological Museum in Moscow.

The Russian copper deposits occur in bands of red sandstone, shale and clay that stretch along the western face of the Ural Mountains from the Barent's Sea on the north to the Caspian Sea on the south (Figure 2). Centered in this belt, some 700 miles east of Moscow, is the city of Perm, the tangible namesake of the ancient Uralian Kingdom of Permia. During the 1840s Sir Roderick Murchison, a renowned British stratigrapher and paleontologist, had come to this region in the course of his studies of the geology of European Russia, commissioned by Nicholas the First of Russia. He named the red sedimentary sequence "Permian" and defined the system to include the beds that overlay the Carboniferous and underlay the Triassic (Figure 1). Gradually his Permian replaced other names for beds of this age and came to be accepted worldwide. The time during which the beds were deposited came to be known as the Permian period.

The Permian has turned out to be a fascinating time in earth history, one of massive changes in the animals and plants of the land and seas, during which the new great continent of Pangea approached its final shape. Biologically, the Permian formed the bridge between ancient life of the Paleozoic Era, which had reigned for almost 300 million years, and the new life of the following Mesozoic Era which, too, flowered, and then suffered a great extinction about 70 million years ago.

The Permian that I had studied in the 1930s and 1940s began to take on a very different look in the ensuing decades.

GEOLOGICAL CALENDAR North America

Figure 1. To the left, a general geological calendar, with approximate dates of boundaries indicated. To the right, the Permian section of part of Texas as covered in the text, with dates of studies of various formations up to 1972.

Figure 2. The USSR, with the western part of the country enlarged to show the location of places mentioned in the text. Permian outcrops are screened. (Enlargement modified from map in E. C. Olson, 1957, translation and condensation of I. A. Efremov, Catalogue of Localities of Permian and Triassic Terrestrial Vertebrates of the Territories of the USSR, Journal of Geology 65:196-226.)

For many years the idea that continents were fixed in their positions since the beginning of time had dominated geological and biological interpretations. True, there were some "heretics" who maintained that the continents had moved, but most of us rejected such "nonsense." Still, during the years before 1950, vague problems of animal and plant distributions and relationships nagged at some paleontologists. Then, as oceanographers and geophysicists began to explore the floors of the oceans and records of ancient magnetic fields preserved in the rocks, concepts of fixed continents became increasingly untenable. Clearly the sea floors had spread laterally from great mid-oceanic ridges and the records of change were preserved in the gave in and accepted the newer theories. Older concepts based on a rigid uniformitarianism were gone!

From application of the new ways of looking at the rocks of the continents and oceans there emerged evidence that, by the beginning of the Permian some 280 million years ago, the great land masses of the earth were coming together to form what came to be a single continent. The continent, called Pangea, was completed during the Triassic. The land masses that are now North America and Europe met earlier to form Laurasia, one of the cores of Pangea (Figure 3). The single continent of Pangea lay astride the equator, which then passed through what is now central Texas and to the south of the latitude where Moscow now stands. It was around this equatorial zone of Laurasia that terrestrial life, plants, insects, arachnids, fresh water fishes, amphibians, and reptiles were concentrated. Beyond the continental limits a great ocean stretched from the west shore to the eastern margins of Laurasia. Much of the recorded marine life of the time was concentrated in shallow seas that overlay the extensive continental shelves and low areas of the continents.

Much later, during the middle and upper Mesozoic, Pangea began to fragment and the formation of the continents as we know them today began to take place.

Collisions of the once separated land masses that went to form Pangea resulted in the formation of persistent mountain ranges, among them the Hercynian-Appalachian chain between two ancient continents, Laurasia to the north and Gond-wana to the south. The Ural Mountains developed along the eastern border of Laurasia as the continent moved, and later these mountains came to form much of the border between present day Europe and Asia as the Siberian continent merged with Laurasia {Figure 3).

During the Carboniferous period, continental ice sheets had formed in the Antarctic regions of Gondwana, leaving unmistakable traces in the rocks they overrode and the sediments they deposited. Around the equator the climates were little affected, but the rise and fall of the seas, likely due to melting and freezing of the ice masses, produced cycles of sedimentation during which formed the great deposits of the Carboniferous coal swamps. By early in the Permian these cycles of rising and falling sea levels had diminished and gradually disappeared.

evidence of reversals of earth's magnetic field. The continents had been forced into movement and underwent massive changes in their alignments. The burgeoning data were formulated into a sweeping theory of plate tectonics, under which the crust of the earth is envisaged as being made up of a series of rigid plates which move slowly, in our perspective, but inexorably.

For many of us during the 1960s plate tectonics was a shattering concept, We were prone to reject it, for it shook the whole basis of geological theory. Western Europeans found it easier to accept than many others, although the Russians lagged! In North America, the east coast came along faster than the bastion of geological conservatism of the Midwest where I had been nurtured. It is terribly hard to give up an ingrained paradigm that has served so well.

Like many of my colleagues who studied ancient vertebrates of the Permian and earlier times, I had been a bit uneasy about fixed continents, for they did pose serious problems in intercontinental migrations of ancient cold-blooded animals. We knew that somehow animals and plants had passed rather freely between North America and Europe and also between South America and Africa. Land bridges did not satisfactorily solve the problem and ocean rafts seemed woefully inadequate. Somewhat reluctantly we accepted the notion that some sort of massive land connections had existed. Even as recently as 1971, however, in a lengthy book I had written over the preceding five years, I included only the slightest hints that continental mobility might hold the answers to the biogeographic dilemmas I addressed. The answers were, however, really there to be grasped at the time. At length, even the most adamant diehards Marine animals, among them trilobites, corals, clams, snails, nautilus-like cephalopods and one-celled foraminiferans, had flourished in shallow continental and shelf seas from near the beginning of the Paleozoic era. As Pangea developed, these seas were expelled from the continents and the living space of their inhabitants was drastically reduced. Coincidentally, and probably partially as the result of the expulsion of the seas, the marine animals underwent the greatest mass extinction recorded in geological history. Mass extinctions had happened before and were to happen again, as when the great dinosaurs died out, but never to the extent that occurred in the Permian. Animals and plants on land were affected as well, but less severely. Changes were, however, great enough to set the stage for a new expansion marked by the rise of the Mesozoic reptiles, including the dinosaurs, and the first birds, mammals and flowering plants.

Climates over the whole earth were severely modified by the formation of Pangea, increasingly so as the Permian progressed through its 50 million years. Early in the period the warm, lush equatorial climates of the Carboniferous coal measures began to yield to somewhat drier and more seasonal conditions. Desert climates gradually prevailed around the equator as the growing mountains blocked the easterly equatorial winds, and all traces of Permian terrestrial life in the North American equatorial region appear to have vanished. As the equatorial climates deteriorated, however, areas both to the north and south of the paleoequator appear to have become more suitable for life on land. It is from deposits formed in these latitudes, best known from the Soviet Union, South Africa and East Africa, that Upper Permian vertebrates are found.

Interpretations of shifting continents, Pangea, paleocli-mates and distributions of plants and animals based on the "new geography" are very recent. They may again undergo radical changes in the future, but whatever happens they have radically modified the concepts of earth history in vogue when our work in the Permian began.

Our field studies at first followed directly in the footsteps of the earlier collectors in Texas, unaware for the most part, as they were, of the increasingly important finds being made in the Soviet Union.

The first collectors in Texas, beginning in the 1870s, were hardy men, no Jeeps or even Model A Fords, no bulldozers and not much store-bought food, but rather a team and buckboard, a rifle, some hardtack and a bag of salt. The problems of getting onto land where fossils occur, often difficult later, were more those of Indians than of ranchers and the Bureau of Land Management. Some 65 years of tramping the Texas red beds looking for fossils had convinced the various collectors by 1935 that those red beds which formed during increasingly hard times, as desert conditions approached, would produce no fossils. The picture emerged of a great desert devoid of all vertebrate life after the time of deposition of the early Clear Fork, the Arroyo formation (Figure 1).

After having had some fair success in collecting in the well known Texas localities, I began to wonder, as others had before, if there might not be fossils in the higher beds (Figures 4, 5). The rocks didn't look much different; they just had not yielded any fossils. Young and improperly indoctrinated, I did not take the "great desert" idea too seriously. So we tried going higher, which meant going west from the standard sites, for the beds dipped gently to the west — about 50 feet to the mile — so that successively younger beds were exposed westward across the section. This dip, along with the simple structure of the beds and only a very modest increase in altitude, assured that higher beds were exposed in that direction. This venture paid off surprisingly well, taking us well into the base of the Upper Permian. But we, too, ran into a great desert with beds of gypsum, sands and mud, a miserable mix for producing fossils. Land animals almost surely were living somewhere in North America, but we have not been able to find their remains even through weeks spent searching in all of the areas where we felt they might be preserved. Perhaps someone, sometime, somewhere will find them and our "great American desert," too, will become a myth.