If you are interested in dinosaurs, the last two years have seen a slew of great books published, and there is more in the pipeline. The latest I am reviewing here is The Dinosaurs Rediscovered from the well-known British Professor of Vertebrate Palaeontology Michael J. Benton. With a huge number of possible topics you could write about, and an already saturated book market, Benton has set himself a very specific aim: to show how the science of palaeobiology has moved from a descriptive, speculative scientific discipline, to a hard, testable, rigorous one. In other words, given that palaeontologists nowadays regularly make some pretty amazing and precise claims about creatures long extinct, how, exactly, do they know that?
Not so long ago, the idea that giant reptiles once roamed the earth was novel, unbelievable to some, but their reign represents only one part of deep time. Go back further in time, to the Carboniferous (358.9 to 298.9 million years ago), and you will find a world of giants as bizarre and otherworldly as the dinosaurs must have once seemed to us. A world where clubmoss trees grew up to 50 metres tall, with scorpions as large as dogs and flying insects the size of seagulls. With Carboniferous Giants and Mass Extinction, palaeobiologist George McGhee, Jr. presents a scholarly but fascinating overview of the rise and fall of this lost world, and why it still matters to us.
Mammoths and sabertooth cats are but two icons of an assemblage of large animals, or megafauna, that disappeared between roughly 50,000 to 12,000 years ago. As with all mass extinctions, several explanations have been put forward, but one man and his idea take centre stage in these discussions: Paul S. Martin’s overkill hypothesis. In End of the Megafauna, palaeomammalogist Ross D.E. MacPhee carefully scrutinises this idea, weighs up the arguments for and against, and explains its enduring allure. To quote Huxley, is this another example of “the slaying of a beautiful hypothesis by an ugly fact”?
Before plate tectonics became an accepted idea in geology, Lyell’s doctrine of uniformitarianism still ruled supreme (see my review of Cataclysms: A New Geology for the Twenty-First Century for a short introduction). A corollary was that the continents supposedly had always been where they are now. One observation scholars had to explain away was that the same fossils occur on both sides of the various oceans. Looking at maps, some people noticed the thin strip of land connecting North and South America and concluded that land bridges must have formed and sunk beneath the waves at just the right times in history to enable migrations (see Four Revolutions in the Earth Sciences: From Heresy to Truth for more details). As explained in The Tectonic Plates are Moving!, we know better nowadays. Nevertheless, the concept of land bridges is still alive and well today, and palaeobotanist Alan Graham here introduces five of them, exploring their effects on biogeography, climate, and human history.