Big, Bad & Very, Very Toothy: A Shark’s Tale

by Richard Conniff/The Wall Street Journal

Megalodon lived. Past tense. The largest shark ever, and arguably the largest predator, went extinct 2.6 million or more years ago. And it has stayed that way. But Hollywood sequel makers will be pleased to know that megalodon still somehow manages to kill on average two people a year, according to Tim and Emma Flannery. More on that later.

In “Big Meg: The Story of the Largest and Most Mysterious Predator That Ever Lived,” the Flannerys, a father-and-daughter pair of Australian scientists, provide a more complete and accurate picture of megalodon than you are likely to see on any television or movie screen. The authors tell us, among other things, that megalodon had nurseries in parts of what are now Maryland, South Carolina and Florida; that it was warm-blooded; and that its young were more than 6 feet long at birth. Like some modern sharks, but on a grander scale, megalodon practiced intrauterine cannibalism, and only the strong emerged to see the outside world. The adult megalodon, the Flannerys write, was big enough to be the scourge of the seas and an “emblem of all the unspoken, hidden terrors that haunt our imaginations.”

Just how big? Was it 50 feet long? Or maybe 65? The book is vague on such details for good reason. Not only does megalodon not exist in the modern world; there is also hardly any fossil evidence, apart from its teeth, that it ever existed. Megalodon’s massive body was built on cartilage, not bone, and cartilage does not fossilize well. The Flannerys hold out hope that a “whole-body” megalodon fossil might someday turn up, a result of extraordinary circumstances of preservation. It happened in 2017 for a contemporary, the giant mackerel shark, an extinct ancestor of today’s great white shark. But the lack so far of anything comparable for megalodon means that the Flannerys must often resort to “mights,” “maybes” and “just imagines.”

About megalodon teeth, their account is sharply detailed. Megalodon’s mouth contained about 272 of them, arranged in four rows, rotating forward as the front teeth broke off in heavy use. And heavy use is what they got. Whales were their common prey, according to the Flannerys, and megalodon’s mouth was big enough “to swallow an orca whole.” Biting and shaking its way through such massive prey, a single shark could shed tens of thousands of teeth over its centurylong life. Unlike its cartilaginous skeleton, its arrowhead-shaped teeth were made of unusually hard material and remain scattered abundantly across the planet.

Dawn of The Flying Murder Heads

The bristling teeth of Anhanguera piscator were for snagging fish. (Photo: Robert Clark)

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By Richard Conniff/National Geographic

Heading out into the geological layer cake of Big Bend National Park in southwestern Texas, British pterosaur researcher Dave Martill proposes a “to do” list for this brief reconnaissance: 1.) Find a rattlesnake to admire. 2.) “Find a complete Quetzalcoatlus skull sitting on the ground.” The odds are almost infinitely better for item one.  But he and Nizar Ibrahim, a fellow paleontologist, promptly fall into a detailed discussion about how to obtain a research permit in the event of item two.

This is the first rule of pterosaur research: You need to be an optimist. Thinking you will go out on a given day and find any trace of pterosaurs—the winged dragons that ruled Mesozoic skies for 162 million years–is like buying a Powerball ticket and expecting to win. Pterosaur fossils are vanishingly rare. Their whole splendid world, built on hollow bones with paper-thin walls, has long since collapsed into dust. Scarcity is especially the rule for Quetzalcoatlus northropi, thought to be one of the largest flying animals that ever lived, nearly as tall as a giraffe, with a 35-foot wingspan, and a likely penchant for picking off baby dinosaurs.  It’s known from a few fragments discovered at Big Bend in 1971, and not much else.

Ibrahim and Martill at Big Bend (Photo: Richard Conniff)

Martill and Ibrahim spend three days bone-hunting among the fissured hillsides. They cross and re-cross the promisingly named “Pterodactyl Ridge,” frequently consulting the “x-marks-the-spot” on maps left by the discoverer of Quetzalcoatlus. They decipher the nuances of geological strata (“Look at that Malinkovitch-controlled cyclicity!” Martill exclaims, referring to the way the Earth’s shifting movements show up in the rock), and they conjure up forgotten worlds. On a sandstone ridge with no obvious way down, Martill remarks, “Haven’t found a mountain yet we can’t fall down,” plunges forward, and emerges unscathed below, eyes fixed on the passing landscape.

They do not, however, stumble across any rattlesnakes, nor even the faintest whiff of a pterosaur. The femur of an Alamosaurus, the largest North American dinosaur that ever lived, turns up, by way of consolation. But dinosaurs are not pterosaurs, or vice versa. Leaving the park, the two paleontologists are already mapping out a return search for Quetzalcoatlus, permanently hooked on the tantalizing pterosaur mix of extreme biological richness glimpsed through the rarest of fossil remains.

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Optimism against all odds has, however, lately begun to look almost reasonable in pterosaur research, with a rush of discoveries revealing

Tyrannosaurs: It’s Not Just About Rex

by Richard Conniff/Wall Street Journal

Given that tyrannosaurs are the most studied of all dinosaurs, and familiar to almost everyone above the age of 5 (or maybe make that 3), it’s extraordinary how little we really know about them: huge bodies, big spiky teeth, tiny arms, scary as hell. That’s about it for most of us.

Go a little deeper and we mostly go wrong, according to David Hone, a paleontologist at the University of London. “Tyrannosaurs,” he writes, in “The Tyrannosaur Chronicles,” “were not pure scavengers; they didn’t spend their lives battling adult Triceratops, they did not have poor eyesight, they could not run at 50 km/h, females were not bigger than males,” and they weren’t all Tyrannosaurus rex, that flesh-rending, scenery-chomping, lunkheaded box-office giant of our nightmares.

Mr. Hone’s unsensational and resolutely middle-of-the-road account lists 29 tyrannosaur species. He adds that