American Scientist

Ancient Marine Reptiles. Jack M. Callaway and Elizabeth L. Nicholls, eds. 501 pp. Academic Press, 1997. $64.95.

In a world so gaga over dinosaurs, it is pleasing to see marine reptiles get their due, as they do in this attractive, multi-authored volume of technical reports. Marine reptiles, last treated comprehensively at book length by Samuel Wendell Williston in 1914, were part of the undeniable charm of the Mesozoic—regrettably, they dwindled in the Cretaceous and stragglers (turtles, crocodiles, sea snakes, a marine iguana) have played only a minor role in marine ecosystems since. Marine reptiles are a paraphyletic assemblage of reptilian types all equipped with appendages specialized to varying degrees for life in the water. They range taxonomically from turtles to crocodilians. All except for turtles were highly predaceous.

This book covers the five major taxonomic groupings plus a section devoted to faunas, behavior and evolution. Each part has an excellent synthetic introduction that frames the major questions and reviews the overall taxonomy and phylogeny of that group.

The foreword by Michael Taylor reviews the history of discovery in early 19th-century Britain. The first prehistoric vertebrates whose images captivated the public were not dinosaurs but plesiosaurs and ichthyosaurs, playfully reconstructed in a teeming marine ecosystem by Henry De la Beche in 1830. Indeed, plesiosaurs quickly took on menacing aspects in gothic reconstructions of "sea dragons" popular by 1840. Dinosaurs ascended in the public imagination only after the concrete reconstructions that Waterhouse Hawkins erected at the Crystal Palace achieved great popular success in 1854. Gorden Bell recounts the story of the celebrated mosasaur recovered from Maastricht, the Netherlands, in 1780 that was carted off to Paris in 1795 as a trophy of war, there to be described by Baron Georges Cuvier in 1808.

Ichthyosaurs are the quintessential marine reptiles, exquisite streamlined creatures so highly adapted for life at sea that they have seemingly abandoned access to the land for reproduction. They ranged from the size of a salmon to that of a whale. Triassic forms give little indication of their ancestry. Plesiosaurs form the "Nessie" morphotype of long-necked swimmers so familiar in popular culture. Sea turtles differ from the classic marine reptiles above in that they survived the terminal Cretaceous extinctions that purged the globe of so many interesting reptiles.

Some of the most interesting papers in the collection deal with functional aspects of marine reptiles. Rachel Collin and Christine Janis, for example, observe that no marine reptiles employed suspension feeding on plankton, a mode of life common among fishes and whales. Mammals evolved facial musculature and distinctive coordinated swallowing reflexes, useful for nursing, that led to plankton feeding in a marine setting. Lacking this anatomy of the oral and pharyngeal regions, reptiles were confined to ingesting large chunks of prey. Robert Carroll examines long-term, large-scale evolutionary phenomena as reptiles repeatedly moved from the land to the sea 20 times or more. In the best-studied cases he notes a rather slow and prolonged pace of change, with little evidence of punctuation.

All told, this attractive book is a welcome compendium of the state of studies in marine reptiles. It will appeal to students of vertebrate paleontology and vertebrate biology. My only significant gripe is that the table of contents neglects to include the authors. Were I a contributor, I would be annoyed—Peter Dodson, Veterinary Medicine, University of Pennsylvania