THE extinction of the dinosaurian reptiles obviously had nothing to do with human stupidity and ignorance, but responsibility for the loss of the remaining big reptiles does lie with us. In their different ways, these three new books on giant tortoises, iguanas and the extinct giant megalanid lizards of Australasia all tell the same sorry tale of loss and destruction. Their common aim is to engage our interest, rather than futile breast-beating.
The 44 species of iguana stand the best chance of survival. By comparison, the two species and 11 Galapagos Island subspecies of giant tortoise are at considerable risk, especially the Galapagos ones. It is definitely too late for Megalania.
The biological story of all these animals starts in the mid-19th century with the usual suspects 鈥� Charles Darwin and the English anatomist Richard Owen. In A Sheltered Life micro-palaeontologist Paul Chambers tells the wonderful but also pathetic 鈥渦nexpected history鈥� of the giant tortoise for the general reader. He sets it within the rich socio-historical perspective of 19th-century science 鈥� the Darwin story and its aftermath.
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Darwin looked forward to visiting the Galapagos but left with ambivalent feelings. On the one hand, he likened the islands to 鈥渢he cultivated parts of the Infernal regions鈥� inhabited by 鈥渓arge, most disgusting, clumsy lizards鈥mps of darkness鈥�. But on the other: 鈥淭hese islands appear paradises for the whole family of reptiles. Besides three kinds of turtles, the tortoise is so abundant that a single ship鈥檚 company here caught from 500 to 800 in a short time.鈥�
Iguanas: Biology and conservation has 20 academic papers ranging from evolution to ecotourism and conservation, written over the past 30 years or so. Large and relatively long-lived plant-eaters with complex behaviours, iguanas deserve all the detailed attention they are at last getting.
Almost every aspect of their lives needs further investigation, which is strange considering the huge impact their discovery had on early 19th-century biology and palaeontology. They provided the models for Gideon Mantell鈥檚 first descriptions of the dinosaur Iguanodon and its reconstruction by Richard Owen at Crystal Palace in London. Using just a few fossil bones, Owen was first to describe and name Megalania, meaning 鈥渢he ancient great strider鈥�.
Palaeontologist Ralph Molnar鈥檚 Dragons in the Dust is a fascinating attempt to recover the life and times 鈥� 4.5 million to about 46,000 years ago 鈥� of this giant monitor lizard. Growing to 7 metres in length and weighing up to an impressive 620 kilograms, Megalania must have given humans first entering Australia some 50,000 years ago quite a shock. As Molnar says in that wonderfully understated Australian way: 鈥淚t was a formidable creature that could discourage people from interfering with it.鈥�
鈥� A Sheltered Life: The unexpected history of the giant tortoise by Paul Chambers, John Murray, 拢17.99, ISBN 0719565286
鈥� Iguanas: Biology and conservation edited by Allison Alberts and others, University of California Press, 拢42.95/$65, ISBN 0520238540
鈥� Dragons in the Dust: The paleobiology of the giant monitor lizard Megalania by Ralph E. Molnar, Indiana University Press, $35, ISBN 0253343747