In 1998, a team of palaeontologists prospecting in the badlands of Saskatchewan in Canada made a significant discovery. Thousands of coprolites – as fossilised faeces are termed – had been found over the years and some of these had been convincingly identified as the excreta of herbivorous dinosaurs. Yet never before had one been securely attributed to a carnivorous dinosaur.
No wonder that the palaeontologists, when they wrote about their find in the journal Nature, were barely able to suppress their excitement and pride. “This specimen,” they reported, “is more than twice as large as any previously reported carnivore coprolite, and its great size and temporal and geographic context indicate that it was produced by a tyrannosaur – most likely Tyrannosaurus rex.”
The identity of the creature that now holds the record for the largest turd known to have been dumped by a terrestrial carnivore seems entirely fitting. Ever since it was identified as a distinct species in 1905 by the eminent American palaeontologist Henry Fairfield Osborn, Tyrannosaurus rex has reigned as the best-known dinosaur of them all. Even its name, a vaunting mixture of Greek and Latin, beats all others in the Linnaean taxonomy for sheer imperiousness: it means “king of the tyrant lizards”.
For more than a century, it has stalked the imaginings of children and film-makers alike as the biggest, baddest predator ever to have walked the earth. Not for nothing was T rex cast as King Kong’s most vicious adversary (human beings aside) and as the lawyer-munching, Jeep-chasing superstar of Jurassic Park. Although other carnivorous dinosaurs have been found since its discovery that exceeded it in length, none is known for certain to have exceeded it in mass. Tyrannosaurus rex still richly merits its name and its celebrity.
It’s not only in popular culture that T rex casts a long shadow. As David Hone cheerfully acknowledges in his gripping and wonderfully informative book about the tyrant kings, palaeontology has been so obsessed by tyrannosaurs, and for so long, that they have become “the best model for future research” in the field. “Quite simply,” he writes, “we know more about Tyrannosaurus than any other extinct dinosaur, and as a result its biology is a superb topic for discussion (and as a bonus for me, it’s therefore an ideal subject to write a book about).”
It is – and one to which Hone does more than justice. Both an accomplished writer of popular science, with a dinosaur-themed blog for the Guardian, and an eminent scholar of tyrannosaur behaviour, he is perfectly qualified to illuminate for a general readership the breakneck developments in his field of study. And it helps that, in many of these, he has played a leading role.
Hone’s interest in the tyrannosaur coprolite that was found in 1998, for instance, was piqued by more than its size. Contained in the fossilised faeces were the bones of an infant hadrosaur – a herbivorous, duck-billed dinosaur. Weighing up this and other fragments of evidence, Hone proposed in a groundbreaking 2009 paper that tyrannosaurs – and, by implication, other carnivorous dinosaurs, too – had preyed largely on juveniles. In other words, the illustrations in children’s books had it wrong. Tyrannosaurs did not, as Hone wryly puts it in this book, “spend their lives battling adult triceratops”. Given the choice, they would invariably pick on smaller prey.
Since 2009, Hone has been able to refine his understanding of their feeding habits even further. Not simply predators, tyrannosaurs were scavengers as well. Hone’s book offers a number of grimly vivid vignettes.
A near-complete hadrosaur skeleton that he studied was in immaculate condition, except for a single humerus (a limb bone) that was covered in deep bite marks and “looked as though someone had taken a particularly rough cheese grater” to it. Hone proposes that the hadrosaur had died and had been almost completely covered by sediment – but with just enough of its forelimb exposed to attract the attention of a hungry passing predator.
Another dinosaur skeleton that bore the marks of scavenging was that of an infant tyrannosaur: it was clearly the victim of some opportunistic cannibalism. At such moments in the book, the millions of years that separate us from the Mesozoic era seem to drop away.
Indeed, as an introduction for the general public of a long-extinct creature, The Tyrannosaur Chronicles deserves to rank alongside Richard Fortey’s Trilobite! as a feat of literary resurrectionism. Naturally, there remains a formidable amount that palaeontologists do not know and probably never will, not least about the origin of the tyrannosaurs. Hone’s guess is that they first appeared in the early Jurassic period, about 190 million years ago – which would suggest that they flourished, as a lineage, for 125 million years in all.
Tyrannosaurus rex, which ranks as merely the best-known of at least 25 species of tyrannosaur to have been identified, succumbed in the end to bad luck on a cosmic scale, literally so. “All those dramatic images that abound of a tyrannosaur in front of a burning world, or left as a charred skeleton on a burnt plain, are perfectly legitimate. The tyrannosaur line only ended with the mass death of so many of its relatives.”
Yet here, 65 million years on, we have Hone’s portrait of it and tyrannosaurs turn out to have been even more awesome and wondrous than my six-year-old self could have imagined. Scientists can be reasonably confident now – as they were not when I first drew a T rex flinging itself with suicidal ferocity on to the horns of a triceratops – that tyrannosaurs moved with their tails stiff and held high; that, at least when young, they were endothermic; that they were feathered, much like birds.
Hone also imparts more intimate details. He tells us that tyrannosaur eggs were probably laid by teenage mothers; that some of the “plains- and desert-dwelling tyrannosaurs may well have evolved a set of eyelash feathers”; that if and when a tyrannosaur did attack a triceratops and give its horns a gnaw, this was almost certainly a beginner’s mistake. We know all of this – and even the size of their poo. The wonders of palaeontology are infinite.
Tom Holland’s latest book is Dynasty: The Rise and Fall of the House of Caesar (Little, Brown)
The Tyrannosaur Chronicles: The Biology of the Tyrant Dinosaurs by David Hone is published by Bloomsbury Sigma (304pp, £16.99)
This article appears in the 20 Apr 2016 issue of the New Statesman, Shakespeare 400 years Iater