The Secret History of Sharks

The Rise of the Ocean's Most Fearsome Predators

About the Book

From ancient megalodons to fearsome Great Whites, this book tells the complete, untold story of how sharks emerged as Earth’s ultimate survivors, by world-leading paleontologist John Long.

“Will keep you on the edge of your seat from its first page to its last page.”—Jared Diamond, Pulitzer Prize–winning author of Guns, Germs, and Steel

Sharks have been fighting for their lives for 500 million years and today are under dire threat. They are the longest-surviving vertebrate on Earth, outlasting multiple mass extinction events that decimated life on the planet. But how did they thrive for so long? By developing superpower-like abilities that allowed them to ascend to the top of the oceanic food chain.

John Long, who for decades has been on the cutting edge of shark research, weaves a thrilling story of sharks’ unparalleled reign. The Secret History of Sharks showcases the global search to discover sharks’ largely unknown evolution, led by Long and dozens of other extraordinary scientists. They embark on digs to all seven continents, investigating layers of rock and using cutting-edge technology to reveal never-before-found fossils and the clues to sharks’ singular story. 

As the tale unfolds, Long introduces an enormous range of astonishing organisms: a thirty-foot-long shark with a deadly saw blade of jagged teeth protruding from its lower jaws, a monster giant clams crusher, and bizarre sharks fossilized while in their mating ritual. The book also includes startling new facts about the mighty megalodon, with its sixty-six-foot-long body, massive jaws, and six-inch serrated teeth.

With insights into the threats to sharks today, how they contribute to medical advances, and the lessons they can teach us about our own survival, The Secret History of Sharks is a riveting look at scientific discovery with ramifications far beyond the ocean.
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Praise for The Secret History of Sharks

“Sharks scare and fascinate us. How did they evolve? How did they beat out the ocean’s other giant predators of the past, like carnivorous marine reptiles? Is it ever safe to swim with Great White Sharks? What else do sharks do to make a living, besides eating us and other big prey? This book, by shark expert and great writer John Long, will keep you on the edge of your seat from its first page to its last page.”—Jared Diamond, Pulitzer Prize–winning author of Guns, Germs, and Steel

“In this magnificent book, the eminent paleontologist John Long tells the true story of sharks and their evolutionary legacy spanning hundreds of millions of years. Rich with scientific detail and enlivened with stories from Long’s decades of fossil discoveries and cutting-edge research, this book is the work of a master scientist and storyteller. It will make you see sharks in a new way: not as blood-thirsty monsters that we should fear, but as nature’s ultimate survivors that can teach us about evolution and environmental change.”—Steve Brusatte, professor and paleontologist at the University of Edinburgh and New York Times bestselling author of The Rise and Fall of the Dinosaurs
“Dive in to this effervescent, engaging biography of the world’s most misunderstood creatures. Evolving in obscurity almost half a billion years ago, sharks have endured the worst that the earth could throw at them. They were here long before the dinosaurs. When dinosaurs died out, sharks were still here. But will they be able to survive the Earth’s current threat: us?”—Henry Gee, PhD, senior editor of Nature and author of the award-winning A (Very) Short History of Life on Earth

“Every week is Shark Week for John Long, who has spent his life scouring the planet for clues to the mystery of shark evolution. Thoroughly researched and wonderfully narrated, The Secret History of Sharks makes a convincing case that the story of sharks is nothing less than the story of life on Earth. Highly recommended!”—Nate Blakeslee, New York Times bestselling author of American Wolf

“Readers will want to sink their teeth into this.”Publishers Weekly

“Long writes lively, lucid prose, and while this is not a textbook, he delivers an extremely detailed education in the history, anatomy, behavior, and ecology of the extensive shark family. . . . An expert natural history with few stones left unturned. If you enjoy searching for shark teeth, read this book.”—Kirkus Reviews
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The Secret History of Sharks

Chapter 1

The Hunt for the Secrets of Sharks

In Search of Shark Fossils

January 1, 1992, Antarctica: Paleontologists will do anything to find spectacular new fossils. I was no exception. I walked alone, pushing my way forward in thigh-­deep snow toward the brooding mountain of ice and rock directly ahead. In the light snow of that New Year’s Day I was rugged up in my thickest survival feather-­down jacket with several layers underneath my outer woollen pants. Heavy double mountaineering boots protected my feet and a thick woollen balaclava covered nearly all my face, save the eyes, which were protected by sunglasses. It was around minus 4°F and uncomfortably windy. The other three members of our expedition had decided to stay in their tents and rest after the previous long, hard day of sledging, pulling our four Nansen sleds with our two Alpine Ski-­Doos about forty miles uphill from our last campsite, sleds loaded to the hilt with our gear and precious fossil samples.

As the only one on our team who specialized in the study of fish fossils, I had waited eagerly for this day to come, losing sleep over the prospect of finding some highly significant fossils. I felt a little frightened going out this day alone, but the past two months working in remote mountainous regions of Antarctica, navigating our way through many perils, had given me an uncanny confidence that I could safely manage this short trek to the mountain without any hitches. The other team members decided it was too claggy a day for going outside, opting to catch up on daily chores and letters, quietly resting. I told them I would not be long, just a few hours, and if the snow got any heavier I’d head home immediately. We also had a plan in place that if I didn’t make it back by a certain time, they would come searching for me.

I was excited to be finally heading to the famous Portal Mountain, a fossil site high in the remote Transantarctic Mountains, where strange fossil sharks’ teeth had been found by a previous geological party some twenty years earlier. I could possibly find a new species of ancient shark that could shed light on what sharks had been doing in this great southern land of Gondwana nearly 400 million years ago.

I just had to get onto the rocky ledges a couple hundred feet away. Each wind gust felt like pinpricks sucking the warmth from my whiskery, ice-­covered face. The snow was waist deep and getting harder to plow through. In places it felt light, kind of hollow underfoot. Then it happened—­I broke through the ice—­and for a fleeting second, I felt my feet dangling in midair as I began to drop. Immediately thrashing my body to one side, I landed facedown, sideways to the ice crack, buried deep in snow. I was panting vigorously and my heart was pounding as I slowly pulled myself away from the death trap, stood up, shook the snow off, and looked back at where I had fallen. There, just behind me, loomed a deep, dark, ominous crevasse about two feet wide. I couldn’t see the bottom.

I struggled on toward the Portal, placing each foot carefully in the deep snow, and after half an hour managed to make it safely to the base of the mountain. Once secure on the solid ledge of pale sandstone, I let it all out. I cried and lamented the near loss of my life, thinking of my family at home, especially my three young children. Before long I snapped back to reality, as it dawned on me that I was at the foot of the Holy Grail of fish paleontology. I was finally, after six years of planning and training for this trip, on the remote mountain where big breakthroughs could be made. I needed to pull myself together and continue, so up the mountain I went.

It had been snowing heavily the past week, leaving the mountain slopes covered in a precariously thick buildup of snow. I pushed my way across a platform of rock that ended in a wide, snow-laden ledge, aiming to get to a better rocky outcrop about a hundred feet away. I had not made two steps when I suddenly noticed pieces of ice whizzing past me from above. Looking up, I clocked a wall of snow rapidly descending upon me. The impact knocked me off my feet; I tumbled down the slope, caught up in a small avalanche.

I swore profusely, thinking it was really not my lucky day. I decided not to press my fate any further, instead focusing on one task: making my way back to camp as carefully as possible. Step by step, I traced my path back, steering well wide of the dreadful spot where I had broken through the ice. Once back at camp safely, in another emotional outpour, I retold my story to the group. I was administered a couple shots of medicinal whiskey before crawling inside my Scott polar tent to rest.

The next day, Brian, our team safety expert, led us back to Portal Mountain. He walked carefully over my tracks. Using a six-­foot crevasse pole, he tested the ground each step of the way, forging a safe access route. He discovered that I had walked over and back across a field of seven crevasses but had broken through only one of them. To this day I feel incredibly lucky to have survived.

That day we found the fossil site I had been looking for and collected some excellent fossil shark remains. For me these fossils made the whole expedition worthwhile. One of these was a giant shark’s tooth, almost an inch in height, sporting two distinct prongs jutting out of a rounded, flat root, which I would later name Portalodus, after the near-­fatal mountain. Over the next few days, I found other new species of unusual fossil sharks’ teeth in the nearby Lashly Range, some thirty miles farther north. At the time I had no idea how important these finds would prove to be. Later, back in my lab, they revealed new evidence of a major shift in shark evolution defining the first time, around 390 million years ago, when sharks suddenly grew to much larger sizes and began invading freshwater habitats.

This is one of many stories you’ll read about how humans hunt for and find shark fossils. Sometimes it’s a dangerous, tiring job involving lengthy exploration of remote sites, hard manual work, and repeated failures where one small clue to the shark puzzle is found after days or weeks of searching. Other fossil sites are easy to access and excavate, with a reliable rate of expected finds, so it’s just a matter of diligence and time (a magic number of hours/days/weeks/months/years of labor) required to find a very special fossil in the right layers of rock.

One of my childhood and student mentors, Dr. Tom Rich, a stalwart American who landed his dream job as a museum curator in Australia back in the 1970s, told me, when I was a teenager on one of his digs, that to succeed in paleontology you need “the will to fail.” He searched the southern cliffs along the Victorian coastline for more than twenty years, hoping to find Australia’s oldest mammal fossils, without success. He never gave up. Then one year his team found a tiny mammal jaw about the size of your little fingernail, the oldest fossil mammal ever found in Australia! Since that day he has found many new species, each helping to dramatically rewrite the story of how Australia’s mammals evolved. Dogged, sheer persistence always prevails.

The human side of the shark story is vital to understanding how our theories concerning the evolution of sharks have changed over time and why. Many of the best fossil sharks featured in this book were found by paleontologists on regular fossil-­hunting expeditions. Some significant discoveries were made by young paleontologists, new to their field, others by veterans having fifty years of experience under their belts. Some of the most important finds were made by amateur fossil collectors, who then worked closely with scientists so that their finds could be studied and published. Each fossil hunter has their own story to tell about why they dedicate their lives to this odd pursuit. Throughout this book I feature the stories of a number of extraordinary people from the past and present who have studied ancient sharks and made significant scientific discoveries. I’ve been lucky to work with several of them and call them my friends.

What got me into this crazy fossil shark business? Sharks have fascinated me from a very young age. I grew up in Melbourne, Australia, a city blessed with many good fossil sites within its urban areas. At age seven I collected my first fossils on a dig with my friend and his dad, then quickly developed a passion for collecting all kinds of fossils, particularly sharks’ teeth. I would regularly head down to Beaumaris Beach in Port Phillip Bay, Australia, about ten miles from where I lived, to go snorkeling in the shallows and find fossils of ancient marine life that inhabited the seas 6 million years ago. My most prized finds were the teeth of giant extinct sharks, including big megalodon teeth (Otodus megalodon). At age thirteen I was one of those overly enthusiastic kids who could identify each shark species by their teeth and tell you what part of the mouth they came from—­upper or lower jaw, front or back. I documented my entire fossil collection in two large exercise books, each a hundred pages long, filled with my color drawings and lengthy descriptions of each fossil. It won me the state’s top science prize in 1972, which came with the hefty sum of sixty bucks, a fortune back then.

About the Author

John Long
John Long is the strategic professor of paleontology at Flinders University, one of Australia’s largest paleontological research groups. The former vice president of research and collections at the Museum of Natural History of Los Angeles County, Long has published more than 200 peer-reviewed papers, some 25 books and over 150 popular science articles. His groundbreaking research work on the evolution of fishes and the origins of sex has appeared in the magazines Nature, Science, and Scientific American. More by John Long
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