THE SAUROPODDINOSAURS

M A R K H A L L E T T A N D M A T H E W J . W E D E L

From The Land Before Time to Jurassic Park, images of fantastically large, long-necked, plant-eating dinosaurs have captured our imaginations. These are the sauropods: center-

pieces of museums and gentle giants of the distant past. Imagine what it must have been like to crest a hill and see in the valley below not just one sauropod, but an entire herd, feeding its way across the landscape.

The most massive land animals ever to have lived, sauropods roamed widely across the continents through most of the “Age of Dinosaurs” from about 220 to 65 million years ago. They reached incredible sizes, giving rise to the question: Why were they so big? Early guesses suggested that they gained protection from predators by virtue of their size, which also allowed them to reach the tops of trees in order to eat leaves and conifer needles. More recent hypotheses hold that they needed a long and complicated digestive tract due to their consumption of low-nutrient food sources: size was an offshoot of that need. Whatever the ex-planation, there is little doubt that natural selection produced something extraordinary when the Sauropoda diversified into a wide variety of species.

This book combines majestic artwork and the best of paleontological research to resurrect the lives of sauropods. The Sauropod Dinosaurs shows how these amazing crea-tures raised and defended their young, traveled in groups, and interacted with the rich diversity of Mesozoic plants

and animals. Beautiful enough to sit on the coffee table, the book also serves as the best reference available on these bygone giants. Anyone with a passion for dinosaurs or prehistoric life will cherish this once-in-a-generation masterpiece.

THE SAUROPOD DINOSAURS Life in the Age of Giants Mark Hallett and Mathew J. Wedel

The Ability to Rear Up

Even as quadrupeds, sauropods never lost the

ability of their prosauropod ancestors to rear on their

hindlegs and tails to reach high levels of conifer

browse. Apatosaurus and other diplodocids were the

most highly specialized for this feeding mode.

Strong Skeletal Support

A sauropod’s spine used the same tensional systems of support

found in suspension bridges (below). In these, cables originate from

vertical towers to distribute the load, and in sauropods the equiva-

lents were single or double spinal processes from which came

strong ligaments for support. Cervical ribs controlled lateral swaying.

The Right Gut System

Most large herbivores process poor quality but abundant

food either with a complex stomach and foregut (cow, left)

or a complex intestine and hindgut (elephant, right). This

breaks down food over long periods of time, aided by mi-

crobes housed in a caecum, releasing a slow but continuous

amount of energy. With no need to chew, sauropods (center)

could efficiently harvest big amounts of food and digest it in

their hindguts.

colon

(cut)

A Flexible Crane

Cranes have rigid beams formed by diagonal struts, which are controlled by

cables that originate from a mast. A sauropod’s neck, though similarly con-

structed, was made flexible by many vertebrae connected by elastic ligaments,

and moved by contractions from a complex muscular system. Big Hearts

The heart of a sauropod was proportionately larger

than an elephant’s, with a particularly huge, thick-

walled pair of ventricles to pump blood up into the

long neck. The arterial system may have had special

muscular swellings to help pump blood, and in the

brain a rete mirabile vascular net to prevent hemor-

rhaging in the brain by absorbing blood pressure.

In the Belly of a Brontosaur

Although no single species is typical of all the others, the body plan

of Apatosaurus excelsus shows the main features of a sauropod’s main

organ systems, which were probably in some ways similar to those

of modern archosaurians like crocs. As did their saurischian cousins,

sauropods inherited a unidirectional lung system like that of birds (see

next spread) and evolved massive, hindgut-dominated digestive tracts

similar to those of large mammals like elephants to slowly process and

release nutrients. A four-chambered heart kept oxygenated and non-

oxygenated blood separate and helped to fuel a metabolism that was

actually or virtually endothermic, like that of a bird’s or mammal’s.

The Right Size Brain

Tiny in absolute size, the brain of

a sauropod was actually as large

as it had to be to direct body

movement and behaviors. It was

well protected from changes

in blood pressure from large,

distendable vascular sinuses.

The best illustrated and most comprehensive book ever published on the largest land animals the world has ever known.

The book includes the following features:

• Over 200 full-color illustrations

• More than 100 color photographs from museums, field sites, and collections around the world

• Thoughtfully placed drawings and charts

• Clearly written text reviewed by major sauropod researchers

• Descriptions of the latest sauropod concepts and discoveries

• A field guide to major groups of sauropods

• Detailed skeletal reconstructions and anatomical restorations

A comprehensive glossary

Naturalist Mark Hallett’s art and writing has appeared in Life, Smithsonian Magazine, and National Geographic. An artistic consultant for Jurassic Park and Dinosaur, he has created dinosaur art and models for the Walt Disney Company and Universal Studios. Mathew J. Wedel is a well-recognized sauropod expert and an associate professor of anatomy at Western University of Health Sciences. He has coauthored papers naming the sauropods Sauroposeidon and Brontomerus.

From even before the time they hatched until they died, sauropod dinosaurs were prime menu selections for a variety of predators. Depending on a sauro-pod’s age and size, these predators took many forms, but the most common and adaptable were their carnivore cousins, the theropods, and during their evolu-tion into giants, the sauropods evolved effective defenses. When a sauropod was finally brought down by predation, its huge body became food not just for theropod hunters but also for a wide variety of organisms.

By chance, a wounded Camarasaurus lentus calf and its companion gain protection among nearby older pod members from attacking Marshosau-rus bicentesimus. In spite of this, sauropods did not care for their young as do today’s mammals, and the mortality rate of juveniles from predation was very high. PREDATOR AND PREY 193

DANGER OUTSIDE THE EGG. The threat to the baby Camarasaurus lentus’s lives be-gan well before hatching. If it was anything like that of a modern crocodile or sea turtle, for a few minutes to half an hour or so before releasing its new lives the nest produced a

faint odor. This was mainly from the smell of the egg contents clinging to the hatchlings and also from the metabolic gases and other wastes produced by the growing embryos inside the eggs. Discernible to humans in the case of crocs and turtles, and very much so to any local raccoon, monitor lizard, feral pig or dog that may chance by, it’s an invitation to a meal. Croc and alligator mothers stick around the nest to defend their eggs, but in the case of turtles’ unattended nesting colonies, only the sheer numbers of nests and quantities of eggs ensure that some will survive to hatch. If discovered, most of the eggs taken are nearest the surface, while the location of those deeper down buys them time until they’re ready to hatch. Around the vegetated fringes of the sprawling sauropod nesting colonies at Auca Mahuevo and elsewhere around the world, there

CHAPTER NINE

PREDATOR AND PREY:THE ANCIENT RACE

From even before the time they hatched until they died, sauropod dinosaurs were prime menu selections for a variety of predators. Depending on a sauro-pod’s age and size, these predators took many forms, but the most common and adaptable were their carnivore cousins, the theropods, and during their evolu-tion into giants, the sauropods evolved effective defenses. When a sauropod was finally brought down by predation, its huge body became food not just for theropod hunters but also for a wide variety of organisms.

By chance, a wounded Camarasaurus lentus calf and its companion gain protection among nearby older pod members from attacking Marshosau-rus bicentesimus. In spite of this, sauropods did not care for their young as do today’s mammals, and the mortality rate of juveniles from predation was very high. PREDATOR AND PREY 193

DANGER OUTSIDE THE EGG. The threat to the baby Camarasaurus lentus’s lives be-gan well before hatching. If it was anything like that of a modern crocodile or sea turtle, for a few minutes to half an hour or so before releasing its new lives the nest produced a

faint odor. This was mainly from the smell of the egg contents clinging to the hatchlings and also from the metabolic gases and other wastes produced by the growing embryos inside the eggs. Discernible to humans in the case of crocs and turtles, and very much so to any local raccoon, monitor lizard, feral pig or dog that may chance by, it’s an invitation to a meal. Croc and alligator mothers stick around the nest to defend their eggs, but in the case of turtles’ unattended nesting colonies, only the sheer numbers of nests and quantities of eggs ensure that some will survive to hatch. If discovered, most of the eggs taken are nearest the surface, while the location of those deeper down buys them time until they’re ready to hatch. Around the vegetated fringes of the sprawling sauropod nesting colonies at Auca Mahuevo and elsewhere around the world, there

CHAPTER NINE

PREDATOR AND PREY:THE ANCIENT RACE

combined genetic recipes from its parents, these may sometimes include mutations, or randomly occurring slight occasional varia-tions in the genetic code. When they do pop up, they are what natural selection acts upon. An animal that’s born (or hatched)

with a minor but detrimental mutation has just that much less of a chance to live long enough to reproduce, while one that inherits some small (but helpful) feature has a slightly better chance to live long enough to pass on its favorable mutation—in this way organic evolution often gradu-ally (but sometimes very rapidly) forms new species over time.

The earliest true sauropods, having emerged in the Late Triassic, had now finally evolved into the shape and body plan we’d recognize, but they were still very primitive or basal compared to later types. Over the ages, these dinosaurs would take many forms, and like the now relict, almost extinct “prosauropods,” were poised to spread out over almost every corner of vast, arid Pangaea. The sauropods now had big bodies and a promising way to feed and support themselves, but where would they go next?

32 THE SAUROPOD DINOSAURS: LIFE IN THE AGE OF GIANT S

In looking at the adult Masso-spondylus carinatus and half-grown young (below), one would never imagine that prosauropods similar to these would someday become the massive, 50-ton As-trodon johnstoni (right), seen here as a life-sized model at the North Carolina Museum of Natural History.

Inside the Fossil Prep RoomThe sun-drenched drudgery of the outdoor field season is in direct contrast to the museum’s fossil vertebrate prep lab, where under the whine of air drills a sauropod skeleton like Diplodocus (skull, above) may take months, even years, of libera-tion from its rocky matrix before becoming available for study and exhibits. If to be exhibited, the bones are usually repro-duced in foam-fiberglas-resin to save mounting weight and to make the bones available for study. The pose of the skeleton may be planned as a scale model (below, left) before its final, full-scale mounting (below, right).

combined genetic recipes from its parents, these may sometimes include mutations, or randomly occurring slight occasional varia-tions in the genetic code. When they do pop up, they are what natural selection acts upon. An animal that’s born (or hatched)

with a minor but detrimental mutation has just that much less of a chance to live long enough to reproduce, while one that inherits some small (but helpful) feature has a slightly better chance to live long enough to pass on its favorable mutation—in this way organic evolution often gradu-ally (but sometimes very rapidly) forms new species over time.

The earliest true sauropods, having emerged in the Late Triassic, had now finally evolved into the shape and body plan we’d recognize, but they were still very primitive or basal compared to later types. Over the ages, these dinosaurs would take many forms, and like the now relict, almost extinct “prosauropods,” were poised to spread out over almost every corner of vast, arid Pangaea. The sauropods now had big bodies and a promising way to feed and support themselves, but where would they go next?

32 THE SAUROPOD DINOSAURS: LIFE IN THE AGE OF GIANT S

In looking at the adult Masso-spondylus carinatus and half-grown young (below), one would never imagine that prosauropods similar to these would someday become the massive, 50-ton As-trodon johnstoni (right), seen here as a life-sized model at the North Carolina Museum of Natural History.

Inside the Fossil Prep RoomThe sun-drenched drudgery of the outdoor field season is in direct contrast to the museum’s fossil vertebrate prep lab, where under the whine of air drills a sauropod skeleton like Diplodocus (skull, above) may take months, even years, of libera-tion from its rocky matrix before becoming available for study and exhibits. If to be exhibited, the bones are usually repro-duced in foam-fiberglas-resin to save mounting weight and to make the bones available for study. The pose of the skeleton may be planned as a scale model (below, left) before its final, full-scale mounting (below, right).

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THE SAUROPODDINOSAURS

M A R K H A L L E T T A N D M A T H E W J . W E D E L

THE SAUROPOD DINOSAURSLife in the Age of Giants

Mark Hallett and Mathew J. Wedel

Publication date: November 2016

9 x 11, 224 pages

138 color photos, 200 color illustrations,

14 b&w illustrations, 10 maps

978-1-4214-2028-8 $39.95 / £26.00 hc

Also available as an e-book

Sales queries: Kerry Cahill Sales Director410-516-6936

Media queries: Jack Holmes Publicist 410-516-6928