Pick from the Past
Natural History, May 1939

Thunder in His Footsteps

The ghost of the most gigantic animal that ever walked the earth is conjured
to life when a lone fossil hunter tracks down the first true footprints left by
this stupendous creature, and thrills to the romance of a great discovery.

“THUNDER LIZARD”—a sauropod dinosaur approximating the one which left his footprints in Texas mud 120 million years ago. He bulked the equivalent of four or five 6-ton elephants. Man would have reached only to his knee.

Drawing by George F. Mason
HERE had been snow on the window of Jack Hill’s store when I looked in; so I wasn’t certain if the things were real or not. Even at that, I had been a great deal more than startled. I walked on past the store window, on down the street facing the whirling cloud of flakes that were northern New Mexico’s first taste of winter, trying to think, trying to find in my mind and in my category of fossil track experience, a niche for these strange objects. It might not do to go back and enter the store appearing too excited over them. Owners of fossils picked up in the rough sometimes are quite ready to place exorbitant value on them, and I’d never met Jack Hill. I stole past the window once more in the casual manner of a man disinterested and glanced in. Yes, they apparently were real enough. Real as rock could be . . . in that Indian trader’s store in Gallup!

I took a last look and resolutely reached for the doorknob. After all, I only wished to see these odd prints at closer range, analyse them more carefully, and identify them if possible. It seemed too good to believe any living creature had made prints like that to turn up here unnoticed and unsung in a trader’s store. Still you never can tell about such things. Anyway I turned the doorknob and squeezed into a large room in which it seemed half the Indians in West Gallup had gathered to escape the vileness of the weather.

A busy clerk nodded assurance when I told him I only wished to examine the strange objects in the window. I made my way past a group of dusky squaws with their bundles on the floor, to the window. My fingers sought the stones, turning them to better light. For a moment I had them to myself —the strangest things of their kind I had ever seen. On the surface of each was splayed the near-likeness of a human foot, perfect in every detail. But each imprint was 15 inches long! Then a big Hopi moved closer, grunting in my ear, laughing. “Zuni tracks,” he said. Out of the corner of my eye I could see the clerk smile: “Do you know of anything, have you ever seen anything, that looked like that before?”

No Known Animal

I had to admit I hadn’t. Furthermore, I could conceive of no animal that might have made them. It was ridiculous to think they were human footprints. They were too large and bear-like: and yet they weren’t like the largest prehistoric bear I could think of, the great Pleistocene cave bear, for the toes were not typical. I felt a keen sense of regret when I told the clerk: “I’m afraid your Jack Hill has found himself a pair of fake footprints.”

It really seemed too bad for both of us. I was finishing a field trip that hadn’t been very productive of fossils for the last two months. True, there had been a couple of rare, rather incomplete dinosaur skeletons collected earlier in the season in Montana —thanks to the assistance of my good friend George Shea of Billings. But here it was almost the end of the season, with almost no hopes for new prospects. If these things had only presented something more tangible to go on. . . .

I was explaining this to the clerk when I learned Jack Hill had some other tracks from the same locality in Lupten. When I heard they were dinosaur tracks in exactly the same type of stone, from apparently an identical stratographic level, my thoroughly revived curiosity could scarcely be retained. This put things in an entirely new light. Even the possibility of such an association seemed incredible. Could I have been mistaken in my first conclusions? I couldn’t believe anything until I’d seen what Hill had in his other store, so that night I drove to Lupten.

MAN, beast, or hammer and chisel? Although of questionable origin, these mysterious, l5-inch, man-like tracks led to the region where the gigantic sauropod left his trail.

Photo by R. T. Bird
The entire affair now presented one of the strangest problems in all my fossil hunting experience. The dinosaur footprints were found as represented and, like the “mystery tracks,” they were fine specimens—too fine. I had every reason to suspect the entire lot had been fashioned by some stone artist, but how they had been so neatly done, how a man could have duplicated the dinosaur tracks at least, without an intimate knowledge of something genuine, there was no means of telling. The latter were typical of some large three-toed carnivore, and all the friction pads showing in the impressions were correct in every detail. Although Jack Hill hadn’t been in town, it was learned both types came from Glen Rose, Texas. A conflicting multitude of questions at once arose: If the dinosaur tracks were genuine, could the strange prints be those of some hitherto unknown reptile? If they were all copied after genuine prints, would there be any chance of finding such if I went to Glen Rose? If a basis could be established for the dinosaur tracks, what might be learned about the others?

To plan on collecting any known type of fossil, the prospector must take into consideration the age in which that particular type came into existence, must be certain that rocks of that age are exposed in a locality where they are said to be evident; yet under all circumstances he must also be ready to gamble on finding still others in situ when he arrives. These tracks presented even the extra gamble of being fakes, but, oddly enough, when I consulted a geologic map, I had a hunch something might be there. Glen Rose was in a region where one might reasonably expect to find actual dinosaur tracks, if not the others. Its surroundings were lower Cretaceous in age—rock exposures roughly 120,000,000 years old—very definitely of the Age of Reptiles. It all seemed too fantastic to put much stock in, but such was the foundation for what might be described as a “mystery hunch.” With still other unexpected things ahead, it proved to be a lucky one.

So Glen Rose became my destination. I arrived with the hunch still strong and healthy, though was relieved to think it hadn’t cost me many extra miles. I didn’t want to feel too encouraged, but the fact also remained this was a region never worked by the American Museum before.

The town and its surroundings were a pleasant surprise. The wooded region up the Paluxy River looked as if it might furnish many favorable campsites. Good drinking water—often as much the concern of fossil hunters as a place to camp—promised to be abundant, for Glen Rose, as a little health resort, had many fine mineral wells close by. Roads were above the average, and the rock exposures I soon expected to be working were right at hand.

Three-toed Surprise

I drove around in the old Buick that has been our expedition mainstay for more years than her disposition shows, drawing these deductions and acquainting myself with other details. When I circled the country courthouse square a little later, my eyes caught sight of something that made me want to shout for joy. There, inserted in a bit of masonry not far from the door, was a large, three-toed dinosaur footprint. Its surface had been turned away from me, and I’d thought for an instant it was the usual fossilised log or stump one sometimes finds exhibited in places where fossils abound. But as I swung the Buick in to the curb it presented in all its outlines a faithful picture of such a track.

It was a beauty, and there was no doubt that it was genuine. It was all of twenty inches of footprint perfection, made by a three-toed carnivore in mud which had faithfully preserved every minute detail. The satisfaction of seeing it was worth my extra miles; it clarified the worst half of an embarrassing problem, and gave promise of other things. A slab of such prints alone would be a fine addition to any museum collection.

A BODY some 60 feet long was supported on these huge thigh bones: skeletal remains in Wyoming of an animal similar to the one that left its 12-foot stride in Texas rocks.

Photo by R. T. Bird
Even so, they were things long taken for granted in the community. I inquired around and soon learned they occurred in numbers in the rock ledges along the river bed for several miles upstream—the river sheering its way through Cretaceous rocks, bringing them to light as it cut along. One close glance at that civic symbol in front of the courthouse had convinced me that the dinosaur tracks in Lupten had been false; that originals from which they had been copied were here—the next thought concerned the others. I hadn’t been able to locate the man from whom Jack Hill bought them, so set out to deal with what the rocks themselves might have to offer. I knew the best way to do this was to get in touch with someone familiar with the river, so I drove upstream and sought James Ryals, whose farm was described as bordering the track ledges conveniently.

I felt a little sorry for the man. He expressed disgust at the very mention of tracks. I learned he’d had his difficulties with them; he occasionally chiseled specimens from the bed of the river to sell, but the financial returns were hardly worth the labor involved. One such specimen lay in the yard. I could hardly wait to inquire about the mystery tracks, and at a favorable moment broached this doubtful subject. I hardly knew what to expect; but much to my surprise he said, “Oh, you mean the man tracks. Why sure, there used to be a whole trail of them up above the fourth crossing, before the river washed them out.”

My surprise was partly overcome by Ryals’ casual reference to them as human footprints. I smiled. No man had ever existed in the Age of Reptiles. But here apparently was the answer to the other half of that baffling track mystery. Maybe Ryals would know of more of them. Often a simple question can save you much random prospecting. My interest was hard to conceal when I asked: “Can you show me one?”

Ryals intended to cut some cedar posts that afternoon and was reluctant to leave, but I finally prevailed on him to walk to the river with me. We didn’t have far to go to find a few dinosaur tracks and were soon peering at several under water and river silt—those at least were evident. Then we came to a place where we had to cross over to reach a track ledge beyond. Finally after jumping from stone to stone we stopped at a shallow hole with a muddy bottom. Ryals sloshed a shovel back and forth and then stood back while the current washed the surface clean. I watched closely as the outline of a foot took form, something about 15 inches long with a curious elongated heel.

A Mystery Print

What I saw was discouraging in one sense, enlightening in another. Apparently it had been made by some hitherto unknown dinosaur or reptile. The original mud had been very soft at this point, and the rock had preserved faithfully this element of softness, but the track lacked definition on which to base conclusions. There was only the one, and though my eyes itched to see a good one, the overlying ledge covered any possible next print. Ryals said he knew of no others exposed at present.

We turned our attention to other things. The three-toed prints occurred in numbers along the ledges, often at the water’s edge and under river silt. Some were the most perfect I had ever seen. A unique situation, however, had accounted for this.

THE PALUXY RIVER, in Texas, has recently eroded sediments, exposing the ancient mudflat on which the dinosaurs left their footprints, long since turned to stone. At right is seen R. T. Bird of Barnum Brown’s dinosaur corps on a lone hunt for footprints planned to be installed in the American Museum’s new Jurassic Hall, just opened.

Photo by R. T. Bird
The limey matrix had originally been firm, viscous mud, ideal for impressions; and the softer shales that represented the muds that filled them later, had disintegrated freely without marring the tracks. However, due to the wear of the Paluxy River, good trails, in a series, were difficult to locate. They’ll have to be in a place well protected by mud, I thought, as Ryals rambled on, telling of still other trails that had been thus torn away or destroyed by this water action. Then we came to a heavy gravel bar, curving around a bend. “Too bad,” he said, looking down at a mass of stones and boulders. “There used to be some fine things under that stuff; I wish you could have seen them.”

Biggest of All

Then he described sauropod footprints. This was startling information, for the group of dinosaurs known as sauropods contains the most gigantic four-footed animals known of any age. I questioned him at length, hesitating to believe the man. Tracks of the largest beasts in Nature! In this type of rock, where tracks were preserved so faithfully, it sounded too good to be true. A sudden desire to dig into the gravel bar almost overcame my better judgment. That indeed, would be a strike I’d little dreamed of—the discovery of these largest of all footprints. But the heavy gravel bar was several feet in depth, and there was no assurance such prints might still remain underneath. The turbulent Paluxy often plays strange tricks with its bottom at periods of high water, when ledges rip away like cardboard. As it had been a long time since Ryals had seen these tracks, I felt it best to conserve my enthusiasm for other things. We moved on, and I temporarily dismissed the subject, but it was a thought to keep in mind.

For the next few days I prospected up and down the river in the old Buick, talking with people and learning of tracks and trails they’d known of, and investigated other possibilities. I became so accustomed to the mention of “man tracks,” that I found I’d adopted the term myself in conversation, though additional specimens of that reptilian footprint with the curious elongated heel were to be found nowhere except in the memories of those who recalled that famous “fourth crossing trail.” As for further information on the sauropod tracks, I encountered only one other man besides Ryals who had ever known of them. This was Ernest Adams, Glen Rose archeologist, who knew the region perhaps as thoroughly as any man. He passed the remark that there was more than one undescribed footprint along the old river which he knew had never been reported—among the lot, those of this heavy quadruped. “I think you’ll find them,” he said.

Still, as I look back on it, I remember I hadn’t been overly excited. All the previously discovered sauropod tracks were vague, not too definable things. None had ever turned a theory, and the possibility of finding such seemed remote. I only knew of two cases, and one of these I’d visited earlier in the season. They were an odd series of 26-inch circular prints, but when one attempted to analyse the trail it failed to jibe as sauropod. The Meyers and I, and several other friends of John MacClary, had spent an exciting half day investigating these tracks southwest of Pueblo, Colorado. I was interested, hopeful, but not excited.

The three-toed prints were made by a fair-sized two-legged dinosaur which fed on other animals and was presumably on the hunt when he passed this way. He towered about thirteen feet high and was a dynamic machine for the pursuit and capture of prey, which he tore to shreds in his powerful jaws and hind feet.

Photo by R. T. Bird
There seemed to be only the three-toed tracks left to work with, so I planned to find the best ones. I wanted to locate a prospective slab for the American Museum. It would have to be done systematically, starting in at the beginning, and uncovering all places where I knew from experience the tracks existed. To take out such a slab would have to be a consideration for the future, but I wanted definite assurance that one was here.

I started above the “second crossing,” worked that area carefully, and then came upstream a mile above the “third.” Tracks had been waterworn and scattering below, but up here prospects were better. Then one morning, little dreaming what lay in store for the day, I finished cleaning off two of the best trails as yet encountered. They had been made by two large carnivores walking close together—creatures with seven-foot strides that would have towered thirteen feet or more in height, probably weighing several thousand pounds each. It was quite evident the mud they walked on had had a firm base, as neither animal sank more deeply than three inches.

The Lucky Strike

Around noon I had finished everything but digging the prospector’s usual “three-feet-beyond-your-specimen-just-for-luck,” when I spotted a large pothole filled with silt that didn’t seem to be anything, but which was right there inviting an investigation. When I dug into it and threw back a few shovelfuls for a look-see, my heart nearly jumped out of my mouth. There, right at my very feet, was a depression totally unlike any I had ever seen before, but one I instantly surmised must be a sauropod footprint. The thing was still partially filled with river silt, and I hardly dared believe it could be, yet its general contours matched perfectly my preconceptions of such a track. It had the shape of a gigantic lizard’s foot, might almost have served to take a bath in, and had been impressed deeply in the surface. Now I recalled Ryals’ mention of such tracks under the heavy gravel bar. “Good old Ryals,” I said to myself, “the man must have been right at that!”

It was like uncovering a place where one of the pillars of Hercules might have stood. My emotions could not have been more stirred over a find of dinosaur eggs. It seemed like an hour, but it must have been less than a minute before my shovel grated bottom, and with a little careful sweeping out the thing was clean enough to be defined. Something about it had seemed almost too easy. Here I had been working diligently all that morning, without suspecting a thing like this was near me; and yet here it was, a sauropod footprint. The river gurgled past me, laughing, as I studied the four deep claw- scratches, the huge one on the inner toe: the typical upward curve of the reptilian heel, and other detail. The print was that of a right hind foot.

Giant Stride

For the next few moments I did the things which any track hunter would have done under the circumstances. I stood up and glanced around the track ledge, wondering where such a gigantic foot had been placed at the end of the next step. The entire ledge on that side was littered with silt thrown from the other trail. The last rise in the river had swept in quantities of mud and this had thoroughly covered this other trail. I figured in a straight line the way the toes were pointed, and shoveled out a likely place. But nothing was there—just solid ledge. Then I ran my shovel along until it hit the rim of another depression.

WHERE THE GROUND “THUNDERED” to the tread of one of the most gigantic four-footed animals the world has ever known: footprints of a prehistoric titan resembling the familiar Brontosaurus, whose name appropriately means “Thunder Lizard.” These prints were associated with the three-toed prints and are the only definite ones of their kind ever to be disclosed. With an enormously long neck and tail, the creature must have measured 60 feet or more in length and stood 15 feet high at the hips. The row of prints shown are all rights; the first left print appearing just above the center of the picture.

Photo by R. T. Bird
It was all of twelve feet away from the other. Heavens, had the fellow stepped that far! I threw about a wheelbarrow load of dirt out of it, trying to orient my conceptions of such an animal. I looked up, half expecting to see a mountain of animal above me. But here it was again, the impression of another right hind foot, like a fossil hunter’s pot of gold at the end of a rainbow.

Then a left print so badly waterworn that I hadn’t suspected it as being a track, over by the river’s edge. Each of these three prints was over a yard in length, by nearly two-thirds of a yard across. All were four-clawed, and as such, could be definitely classified as hind feet. So fascinated that I didn’t think to pull off my shoes, I sloshed around in shallow water just beyond, to locate where both rights and lefts continued. While so engaged I noted still other sauropod tracks in deeper water. Evidently more than one of these fellows had been wandering around there once.

I came back to the dry ledge, satisfied at last. I’d learned where to search for the forefeet by this time—always a little in advance of the rear ones. They were more shallow and hadn’t showed up as readily, but were none the less interesting. Such tracks indicated the foot had been heavily padded with flesh in life, and there was just a trace of the single claw on the inner digit. This was a day of days! Even my beloved chief, Barnum Brown, would have been not a little thrilled at this. I thought of him, then on an aerial survey, up in Canada. I was sorry he wasn’t here. Well, the trail would remain for other times to come.

Can you visualize the great bulk of such a creature that had walked there? He must have approximated the big brontosaur whose huge skeleton now dominates the New Jurassic Hall in the American Museum. When you come into that hall, and look up into that great mechanical mass of articulated bones above you, even then it is difficult to picture such a beast in life. Sixty-seven feet of lengthy neck, backbone and tail; four pillar-like legs with hips alone fifteen feet above the base; shoulders according, and a massive basket for a middle. . . .

Still such a creature once floated a vast body most of the time in lakes and lagoons where favorable plant food abounded. Here a similar sauropod had apparently been moving over a shallow mud flat.

Even if I hadn’t tried, I couldn’t have helped imagining the big fellow was moving along there, time and time again, as I finished cleaning up that trail. At the end of an hour I walked back and sought a high place on the river bank where I could look along it. I wanted now to piece the complete story together around these tracks as the evidence seemed to show it happened; I wanted to catch the detail of a strange and spectacular sight: that of this greatest of all four-footed animals in motion. The smaller, flesh eating dinosaurs had come along there first, for I found a sauropod footprint impressed on one of theirs. It was evident they were terrestrial animals; hence this rock ledge, then a mudbar, must have been exposed close to some shoreline, or at best only covered by shallow water. As previously mentioned, these carnivores were large, yet the mud was firm enough to hold them.

Thundering Ghost

With these thoughts in mind the great dinosaur moved again for me. He was out there on the shallow mudflat coming in from deeper water, progressing in the manner of a heavy quadruped, moving slowly, leisurely, without concern. Beyond were other sauropods, but he, in the foreground, was the central figure, with the sunlight glistening on his moist skin like the glint of a wet alligator crawling on a bank to dry. It glistened on his tiny head and along the great snakelike neck that held it. It followed across his massive shoulders as he moved, and flashed on the ripple of the muscles; it danced over the great broad back and ponderous hips and thighs, to linger on the water after the passage of a lengthy tail. He would have bulked the equivalent of four or five, six-ton, African elephants combined. The heavy mudflats must have trembled under him. You might have felt the thudding jar of every step as he came along; leaving this great trail behind—just as the name Brontosaurus implies. . . . “A Thunder Lizard.”

TICKLING THE TOES of a sauropod for the first time. This cast, made by pouring plaster of Paris into one of the gigantic footprints, shows what the bottom of the creature’s right hand foot looked like. Projections at left represent the toes and claws. Its length is 38 inches as R. T. Bird measures it.

Photo by R. T. Bird
I spent the rest of the afternoon photographing the trail and taking accurate measurements. A sense of both elation and futility marred my dreams that night. It was out of the question to remove even one of these washtub tracks—that would have to be a consideration for the future. In the end I had to be content with a pair of plaster casts. If anything should happen to the originals, they would constitute a record.

As to the mysterious stone artist, I never located such a man, nor did I try very hard to do so; I was satisfied. I really felt as if I owed the man a lot. The strange quest he started terminated in a manner far beyond anything I had expected. If the idea of tracing down originals had not occurred to me, then this story never would have been written. All the prints in Jack Hill’s had been well done— too well done, the only reason to suspect them. The one single “mystery print” that Ryals showed me checked with the descriptions of at least a dozen people, in regard to the others once seen there. How often I wished I could have seen them too! To me they are still as indefinite as the creature that made them. I think more will turn up another day, but that is, again, another hunch.

As for the sauropod tracks, their story is but half told. I have hesitated to deal with technical details in a narrative of this nature. Many interesting things are still to be learned about them, but that, like removing a trail-slab, is a fitting story for the future. This—just a tale of prospecting—has been offered for the value it alone may hold.

Incidentally, the big tracks were still there by the Paluxy River when I last saw them. It will be a hard, strenuous, not to mention expensive, job to take a series of them out. An ideal place to exhibit such a slab has already presented itself to Dr. Brown. There is ample room on the base of the Museum’s Brontosaurus, just under the mounting of his tail. So mounted it will appear as if this big fellow had just stepped out of them. In the river bed they will be soon worn away and lost forever. What could be more fitting than the place described? Like Brontosaurus, he, too, this Texas sauropod . . . had once moved forth against the world with thunder in his footsteps.

To read more about the Paluxy River footprints, see Roland T. Bird’s
later story, “A Dinosaur Walks into the Museum,” published in February 1941.

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