Books >> Science

I got a "5" on the exam, which is the highest score attainable... I think that speaks for itself!

Combinatorics is a relatively recent development in mathematics, one which is generally easy to explain, but with many difficult open questions. Van Lint and Wilson do an excellent job explaining, but there are a few places where the reader needs to know some background to place the particular problem in the appropriate mathematical context. Understandably, if the authors were to include all the mathematical machinery needed, the book would be huge! Instead, they have chosen to describe as many facets of the field as possible, and therefore have written a broad, well-balanced book which approaches the topic in a non-threatening way.

My one criticism, then, is that there is a lack of depth in several areas of the book, with further discussion of advanced topics or open problems. But even so, I can appreciate the omission for the sake of accessibility.

To fully appreciate the subject, the authors are correct in mentioning that the book is written with the graduate student in mind. But by no means does the reader require such a background to appreciate the remarkable concepts and the exciting questions revealed in this book.

This in modern times relates to the Gulf States of Texas, Louisiana, Mississippi, Alabama, and Florida; and the Atlantic States of Georgia, South and North Carolina. The book explains that there were differences in size between the Western and Eastern species of Deinosuchas. And it is especially noteworthy that these Cretaceous crocodylians were animals reaching more than twice the body mass of any living Crocodylus or Alligator species.

A major focus of this book, besides the giant crocodylians themselves, is the unique ecosystems and conditions of these southern Late Cretaceous coastal habitats that enabled such crocodylian populations to develop and flourish for a significant amount of geological time.

This book is NOT hard reading, in fact, this book move right along as we read about the croc's diet, how it hunted and what it ate. There is a lot of anatomy in this book as we see skull fossil remains and teeth, while there is some comparative anatomy Deinosuchus was in a class by itself.

The contents of the book: The Life and Times of a Giant Crocodylian; The Early Paleontology of Deinosuchus; The Size of Deinosuchus; The Age of Deinosuchus; Deinosuchus Localities and Their Ancient Enviornments; How Many Deinosuchus Species Existed?; A Genealogy of Deinosuchus; and The Prey of Giants.

I found the book to be very informative, this is not light reading for children, but children from age 12 and older will be able to understand it. All in all, the life and times of a Giant Croc is the easiest way to explain this book.

The opening chapter starts off a lot like Steve Alten's Meg. A hapless theropod winds up in the wrong place at the wrong time. While Meg's scenario was entirely fictitious (_Carcharocles megalodon_ was not around during the Cretaceous), Schwimmer's scenario is actually based off of some factual evidence. For the rest of the book, Schwimmer justifes his scenario by presenting evidence for the size, habitats and prey of _Deinosuchus_.

Schwimmer breaks up each of the 8 chapters into different sections on _Deinosuchus_. Starting with the semi-fictitious intro, then going into its chaotic taxonomic origin, when, and where it appeared, how big it got, what creatures it was related to, and who was preying on whom back in the Late Cretaceous. All the evidence is viewed objectively, with the author's view stated at the end. Some highlights include an interesting section of the 2nd chapter, which showed some of the bias seen in non-dinosaur/non-mammalian work. More often than not, the reason we know as little as we do about other ancient reptiles, is because of a lack of interest in them. One prime quote from that chapter (pg 29) really sums this up:

"Holland (1909) reported that, upon recognizing the animal leaving all these big bone fragments was a huge crocodylian: 'Mr.Hatcher immediately lost interest in the material...""

Thankfully, this skewed point of view has been slowly changing. If it hadn't, then this book would never have been written. Schwimmer also deals with the infamously inaccurate skull reconstruction that used to be on display on the 4th floor of the AMNH. This reconstruction and numerous pictures based off it, has been used in popular and professional literature to estimate the size and dimensions of the animal. Schwimmer shows how this inaccurate restoration came to be, and exactly what was wrong with it.

Replacing this misinformation, is the most accurate, and up to date measurments of the animal. While the old measurements had _Deinosuchus_ hitting lengths of 50+ ft (based off that inaccurate skull), the newer measurements only shrink the crocodylian down by ~11ft and weighing in at 8.5 tonnes in the largest individuals. While showing off size, Schimmer also shows the readers that there were two different sized populations of this genus. Eastern populations were smaller (~26ft and 2.3 tonnes) and more numerous than western populations. Schwimmer even compares these new size measurements to other giants from the fossil record. In most cases _Deinosuchus_ comes out on top compared to most carnivores of its time, or of any time (to help put things in perspective, this crocodylian was a full 1.5 tonnes larger than _T.rex_).

The book alludes to an interesting trait of fossil "supercrocs." As Schwimmer describes other large crocodylians throughout prehistory (an apparent "trend" in this group), one notices that fossil supercrocs suffer from the exact opposite problem that most large vertebrate skeletons suffer. There tends to be really good skull material, but little, or no postcranial material.

_Deinosuchus_ anatomy is thoroughly discussed. Schwimmers shows just how important crocodylian osteoderms are, and using traits of these osteoderms, shows that erect walking (aka "high walking") was possible in even the largest _Deinosuchus_ specimen. Schwimmer also spends ample time on the unique dentition in _Deinosuchus_. Most of the teeth were short, blunt and rounded. According to Schwimmer this was originally evolved for turtle eating purposes, and was later exapted towards dinosaur eating in the species (especially the western pop). Schwimmer also gives mention to the incredible force exerted by the jaws of these animals and shows that _Deinosuchus_ had the strongest jaws of any animal known to science regardless of time period.

Chapter 7 gives a fairly comprehensive rundown of the group of animals that lead to _Deinosuchus_. It is nice, for it shows just how taxonomically confusing the crocodylotarsi group is, while also going a little farther to dispelling the myth that crocodylians have changed little in 200 million years on earth. Though there was no mention of pristichampsids, or _Stomatosuchus_, Schwimmer does mention _Malawisuchus_ and the new Madagascar crocodyliforme, which had teeth and body forms similar to herbivorous mammals and dinosaurs. With all this variation and diversity showcased, it is somewhat disappointing to hear Schwimmer state that he doesn't consider the crocodylotarsi group to be as derived from basal archosaurs as dinosaurs and birds are (something I completely disagree with). Overall though, this chapter really goes far in highlighting the many different bodyforms that lead to _Deinosuchus_.

The final chapter of the book talks about what, exactly, _Deinosuchus_ was eating back then. Studying the dentition, habitats and evidence of predation, Schwimmer shows that turtles made up a large part of the diet for, at least, eastern _Deinosuchus_ populations. Schwimmer also shows that _Deinosuchus_ in both the western and eastern parts of North America, were not only eating dinosaurs, but were outcompeting the carnivorous theropods in the area (and occasionally eating them too). So, by the end of the book, one has come full circle.

Schimmer's writing style is reminiscent of my own. He doesn't dumb down the technical terms, but instead provides definitions for words and scenarios in parenthesis, or in an appendix (and occasionally goes off on parenthetical tangents like this one). The layout of the book allows one to either read it from cover to cover, or to just pick it up and look for a particular subject. If more info is mentioned later, or earlier in the book, the location is placed in parenthesis for easy reference.

If you're into ancient life, crocodylians, reptiles, or if you just liked National Geographic's: Supercroc special, then I highly recommend this book. _Sarcosuchus_ is cool, but _Deinosuchus_ is the supercroc that started it all. Kudos to David Schwimmer, James Farlow and all the other "Life of the Past" workers, for showing that dinosaurs weren't the only cool creatures alive millions of years ago :)