Holman’s Fossil Snakes of North America by Jonathan Crowe
The OHS News 87 (Dec. 2000)

Fossil Snakes of North America: Origin, Evolution, Distribution, Paleoecology
by J. Alan Holman
Indiana University Press, 2000. Hardcover, xi + 357 pp. ISBN 0-253-33721-6

The study of fossil snakes is not nearly as accessible as you might expect. It’s highly specialized work that doesn’t excite the popular imagination nearly as much as a Tyrannosaurus rex skeleton. The following quotation from Fossil Snakes of North America is instructive:

Fossil snakes usually occur in the form of disarticulated bones, mainly vertebrae and ribs, with a few cranial bones turning up now and then. Rarely, fossil snakes occur as essentially complete skeletons. The problem is that these specimens are usually at least partially embedded in hard rock, which obscures the important diagnostic characters of the individual bones. For this reason, most paleontologists who study snakes would rather have a perfectly preserved middle trunk vertebra than a complete skeleton embedded in rock. (p. 9)

Analyzing the characteristics of tiny snake vertebrae — now really, where’s the fun in that? Unfortunately it will be hard for popular interests in snakes and paleontology to converge: snakes are essentially delicate creatures that don’t fossilize well. Also, we like their pretty colours, which don’t fossilize at all.

All of which is not to fault this book, but it is cold water in the face for those anticipating something more, well, dinosaurish. This is a very dry and technical read: very thorough, lots and lots of detail, easily the reference on the subject, but there’s not much of a narrative to speak of. It does have quite a bit of interesting material. Almost all the North American snake fossils are from the Cenozoic era, and most are from the Pleistocene epoch. While some of the fossils are from extinct snake families, genera, or species, many are from modern taxa — sometimes in locations you wouldn’t expect. Fox snakes in Idaho! They were much more widespread once, but then, they would have had to have been, since their current range was once under a glacier.

You will learn more about the subtle differences in snake vertebrae than you probably ever wanted by reading this book. The shape of a snake’s vertebrae is diagnostic; hardly any other characteristics can be used by the paleontologist. This means that sometimes a fossil can only be tentatively assigned to a genus. It also means a somewhat different species concept.

Unless you’re extremely interested in the subject, this book is best left to specialists.

Note: This article has not been updated since its first publication. As a result, some of the facts referred to in the text may now be out of date.