Info

Translation quick plunderer. A creature that lived up to its name, and then some. Though no heavier than an adult human, Velociraptor was probably pound-for-pound one of the fiercest meat-eating dinosaurs that ever lived. Consider its unusually large eyes and especially the long, clamplike jaws lined with batteries of serrated fangs. No blunt plant-mashing molars, only fangs, each one of them slightly curved and saw-sharp. Walking on its hind legs like Tyrannosaurus, Velociraptor...

The skull of an adult Hypacrosaurus stebingeri found by Jason Horner in Bruce Selyem reproduced courtesy of the Museum

Well within shouting distance of Jason's Giant Site, my son's name for the new quarry, we made a very different kind of discovery a ridge about one hundred yards long and twenty yards wide, both sides of which were paved with dinosaur fossils. Glittering in the afternoon sunlight were thousands of bone fragments belonging to at least several kinds of dinosaur, including, at first glance, hadrosaurs, lambeosaurs, and tyrannosaurs. And that much we determined from a brief visual survey during...

The Livingston Sauropod Site from left to right Jason Horner Donna Coles Allison Gentry and Hilory Korte far right

A two-thirds-grown sauropod near Livingston, in the south-central part of the state. We later learned that the dinosaur probably represents a new species, one that may well be a precursor of Diplodocus and Apatosaurus, both of which it resembles in critical ways. Diplodocus and Apatosaurus. The mere thought of them more to the point, of removing them from the ground makes me shudder. Fully grown, Diplodocus was about ninety feet long and weighed twelve tons Apatosaurus, seventy feet and...

At The Lowlands

The comment came from a good-natured old rancher whose rambling spread encompassed a fossil-rich section of the Milk River badlands northwest of Havre. Of all the foolishness he had witnessed over the years, he evidently had never encountered the peculiar brand that Bob Makela and I were practicing on his land, with his permission if not his full comprehension, one hot summer afternoon in 1972. I've got a pile of bones over there you're welcome to, he offered,...

Captivating Dinosaurs

Six miles below the Canadian line, in the northeastern corner of the Blackfeet Indian Reservation, rests a prominent flat-topped hill called Landslide Butte. The Milk River cuts nearby, the water so sluggish and thick with sediment it looks like liquid chalk year-round. Steep gullies and ragged washes are carved into the scrub country between the hill and the border, everywhere exposing layers of shale, mudstone, and sandstone. It is in heavily eroded, largely barren, outcrop-rich regions like...

Sauropod bone bed excavation on the Turner Ranch TJ Site Bruce Selyem reproduced courtesy of the Museum of the Rockies

Not protection it is hard to imagine an alternative explanation. That was about all I could say on the subject of Jurassic juveniles until the fall of 1994, when Curt Padilla came to see me. Curt is a dedicated amateur collector who has been a friend of the museum for many years, stopping by whenever he and his family find dinosaur specimens he thinks might be of interest to us. This time Curt and his wife had been exploring near Rainbow Butte, where Ostrom's Deinonychus-Tenontosaurus quarry is...

Our attempt to drain a portion of Four Horns Lake to collect a mosasaur skeleton

Covered that the mosasaur skeleton was encased in large nodules of marine limestone that had formed within the layers of shale. Many of the bones were encased in their own nodules, however. Excavating them was simply a matter of mapping their location and carrying them to shore. Other, more fragile sections we covered with plaster jackets, a practice we usually follow to prevent breakage when we remove fossils from the ground and carry them elsewhere. It took several long, wet days to transfer...

Waltzing To The Rhythm Of The Western

Hypacrosaurus

By mid-June 1988, after almost five weeks of digging, the crew at Hillside Quarry had recovered three skeletons of Gryposaurus lati-dens an adult and two juveniles. But the amount of overburden had increased rapidly as they dug into the steep slope, trying to expose more of the narrow sedimentary layer in which the bones were entombed, and it now represented too great an obstacle to further excavation. I closed the quarry and transferred everyone to our new digs. From West Hadrosaur Bone Bed...

The camp along the Two Medicine River Bruce Selyem reproduced courtesy of the Museum of the Rockies

Dition was a couple of rock picks, a tank full of gas, and a cooler of beer, and the only payoff we sought was the thrill of discovering something new. What would he make of this expedition, of all the equipment, people, and ambition arrayed before me in the camp below And how did it look, I wondered, to the large white pelican just then spiraling downward on angling wings, toward the river, landing with a splash alongside its fellows Among those to begin working immediately at the newly...

This clutch of eggs found in the Milk River Badlands was laid by a crested duckbilled dinosaur Bruce Selyem reproduced

Ratios of the isotopes to the parent element we can determine how long the argon has been in the ground and thus the age of the surrounding rock. But there's very little volcanic ash in the Judith River Formation. In the absence of measurable argon, we must rely on less precise methods comparing the sediments with other strata, in both the Judith River Formation and nearby formations, such as the Two Medicine, which have been dated, and studying the sediments themselves for clues to the kind of...

Acknowledgments

Neither this book nor the research it describes would have been possible without the help of a great many people. These include Judy Weaver, Gail Cary, Shelly McKamey, and the entire staff of the Museum of the Rockies. I'm especially grateful to my friends, past and present, in the paleontology department Pat Leiggi, Bob Harmon, Carrie Ancell, Ellen Lamm, Allison Gentry, Bea Taylor, Frankie Jackson, Jill Peterson, Matt Smith, and Karen Chin. Undergraduate, graduate, and postgraduate students...

Cross section of a leg bone showing the internal microstructure VC vascular canals Oc osteocytes HS Haversian system MC

Hypacrosaurus

Bone the sample represents, the age at death of the animal to which the sample belongs, whether the animal had been diseased or injured. What one sees also depends on what one knows about skeletal growth and structure. Reading bones, like reading sediments, is impossible without an understanding of the vocabulary bones use to speak, as it were. For starters, you might be surprised to learn that the comparison of bones and rocks is not entirely metaphorical. Bones are formed in part by...

Man And Dinosaur Whats Ahead

Hypacrosaurus Growth

Translation knowing man. A creature that lives up to its name, and then some. Though physically indistinguishable from its immediate forebears the late Pleistocene hominids that appeared about forty thousand years ago Homo sapiens has grown clever enough to reconstruct the lives of creatures that went extinct ages ago, then to develop fictional accounts of those lives in the form of books and movies. And science and art are but two of its many notable creations. Consider...

Through The Eyes Of A Pelican

A new duck-billed dinosaur, a new crested duck-billed dinosaur, two new horned dinosaurs, four bone beds containing the remains of juvenile and adult dinosaurs, and the largest dinosaur rookery this side of the Pacific Ocean. After collecting an array of specimens from the upper layers of the Two Medicine Formation during the 1985 and 1986 seasons, I decided again to explore its lower, older layers, specifically, those exposed in the southeast corner of the Blackfeet Indian Reservation, along...

Extinction As A Way Of Life

When the Bearpaw regression began about 74 million years ago, the water didn't cease falling until it had withdrawn off the continent, never to return to the upper Great Plains. By 66 million years ago, most of what is now Montana, Wyoming, and the Dakotas was dry. A million and a half years later, the Western Interior Seaway, which had played such a crucial role in the evolution of life along the Rocky Mountain Front during the Cretaceous period, was gone, its entire contents having drained...

Removing a clutch of eggs from the Landslide Butte area Ricky Reagan whose land we were camped on is on horseback

Prosaurolophus a hadrosaur that grew to twenty-five feet in length and weighed a couple of tons also found only in late Cretaceous sediments. Everywhere I walked, it seemed, I also found dinosaur eggshells, countless small, black shards resting on the ground and jutting from outcrops. The specimens we recovered by removing hundreds of pounds of overburden soil and rock lying on top of fossil layers at the Willow Creek anticline we could collect from a single shovelful of dirt in some parts of...

Marine Bearpaw Formation

Centrosaurine skulls in the order in which they are found at the top of the Two Medicine Formation and bottom of the Horseshoe Canyon Formation, with the intervening marine Bearpaw Formation. The asterisks designate the transitional forms. The numbers show the distance the skeletons were found from the top of the Two Medicine Formation. Drawing based on an illustration originally by Kris Ellingsen, and additional morphological data. pointing nose horn whose tip bends slightly backward. The...

Excavation at Jacks Birthday Site in Bruce Selyem reproduced courtesy of the Museum of the Rockies

Having completed almost two years of a three-year-long research project, he would be forced to begin again, somewhere else, if the site were substantially altered. Dave's dissertation depended on the reliability of the information he extracted from Jack's Birthday Site, and that, in turn, depended on the care and thoroughness with which he analyzed the condition of the specimens and measured their location and orientation with respect to each other and to the surrounding sedimentary rock. Once...

Beyond Egg Mountain

What would it be this time An outcrop of rock that had weathered just so, its shape suggestive of some mysterious creature Or the not-very-old skeleton of an all-too-familiar animal that for some reason hadn't been recognized as such These were the questions that were rolling through my mind as Bob Makela and I drove to the Blackfeet Indian Reservation in north-central Montana, a journey of some 250 miles from my home in Bozeman. It was the fall of 1984, the year we removed thirty tons of rock...

Witness To Creation

In his beautifully illustrated book Serengeti, wildlife photographer Mitsaki Iwago portrays immense herds of migrating wildebeests as they ford rivers or endure drought, often dying by the thousands, leaving behind carcasses that in turn make it possible for the region's scavengers, hyenas and vultures, to survive. The pictures serve as a vivid reminder that life and death are permanently entwined, a never-ending tango, sometimes painful, other times pleasurable, but in the absence of which no...

Skull of the tyrannosaur Daspletosaurus found by Vicki Clouse near the Two Medicine River Bruce Selyem reproduced

The study of what happens to the remains of plants and animals after they die, is a crucial tool in determining as well how the plants and animals died, even, in some cases, how they lived. The mere fact that all of the bones at Jack's Birthday Site are disassembled there are no articulated skeletons tells us that movement of some kind has taken place. Indeed, movement is so common among fossils that very rarely do we find intact, undisturbed skeletons, such as the hypacrosaur at Jason's Giant...

Proximal femurdistal femur

Longitudinal sections of embryonic femurs of Troddon and Maiasaura showing the internal structure of the bones. CC calcified cartilage EB endochondral bone M sediment MC marrow cavity PB perichondral bone. position is almost reversed, with five times more bone than cartilage. By contrast, we found that the near-term embryonic leg bones of Troddon are made up of about equal parts calcified cartilage, bone, and marrow. And an even more striking difference is exhibited by Orodromeus, in which only...

Troddon formosus was a predatory dinosaur with good grasping arms and hands and a mouth full of coarsely serrated teeth

Fun to perform but whose results are impossible to verify. Yet as I gazed into the oversize eye sockets of the Troddon birdlike skull, trying to imagine the long, slender snout receding and the low forehead growing wider, I found myself wondering what exactly the world would look like today if some of the events that shaped the natural history of dinosaurs had taken a slightly different turn. In my opinion, the extinction of Maiasaura, Hypacrosaurus, and their kin was neither as neat nor as...

Suspicious Species

Strangers meet and introduce themselves. If they are adults, two questions invariably arise What is your occupation Who are you related to As society grows increasingly mobile and urban, it s true that the second inquiry tends to become less personal Who do you know but the intent is the same. We orient ourselves with respect to others in terms of jobs and social connections. Paleontologists, though certainly more rigorous, adopt a similar approach when they first encounter a new dinosaur....