Digging Dinosaurs - A Review
John R. Horner's Search for Fossil Evidence of Cretaceous Parenthood
Jan 3, 2009
Digging Dinosaurs (Published by Workman Publishing Company 1988, Copyright John R. Horner and James Gorman, ISBN:0-06-097314-5) is the tale of how persistence, preparation and a good deal of luck combined into a whirlwind of scientific progress in the field of paleontology at the tail end of the 1970's. In just under a decade, Jack Horner would go from an obscure preparator at Princeton to one of the preeminent voices in paleontology, complete with an honourary doctorate from the University of Montana.
"Luck is the Residue of Design"
Branch Rickey's famous quote applies equally well to paleontology as to baseball. In 1978, Jack Horner had his sights set on two weeks digging around a few likely spots in Montana. This was unfunded fossil prospecting that Horner undertook during his vacation time. Incredible good fortune routed his hunt through a small rock shop in a tiny town called Bynum.
When the owners of the shop saw that Horner and his friend were able to properly identify some of the shop's fossils that had been misidentified, they asked the two men to take a look at some fossils they had found that spring.
The Brandvold family had found and collected baby dinosaur fossils at a time when there were only a handful of sites in the world that had ever yielded the remains of dinosaur babies. Horner had been in the right place, at exactly the right time.
Nests, Eggs and Hatchlings
Over the next several years, Horner would find not only more fossils of baby dinosaurs, but discover an entirely unknown species of duckbilled dinosaur dubbed Maiasaur peeblesorum. Peeble was the name of the owners of the land on which the fossils were found and Maiasaur roughly translates to "Good Mother Lizard" which was chosen because the evidence pointed to a behavior not seen before in dinosaurs, nesting.
Fossils of baby dinosaurs were found in pits that were dug by the adult dinosaurs, in which the eggs were deposited. Since few eggs were found intact, but much fossilized eggshell remained, the indications are that these dinosaurs hatched and then remained in the nest, trampling the eggs into shards, long enough to grow from a hatchling size of 14 inches until they reached something like 3 or 3 and 1/2 feet in length. Fossils ranging from these two extremes were found in several nests, along with the trampled egg shells, indicating further that the adult Maiasaur would likely have brought food to their offspring and protected the nest from predation.
Herding Behavior, Intact Eggs and Other Finds
Paleontology deals with timescales that dwarf our lifespans. Over the millions of years since the dinosaurs first walked the Earth until they died out some 60 or 70 million years ago, countless waves of migration, predation, natural disaster and geological upheaval have reshaped the landscape. On occasion, a natural disaster some 100 million years ago leaves us with a treasure trove of fossils, and in this case, a mystery.
Over the course of the dig, Horner's growing team discovered several areas that were rich in fossils of adult Maiasaurs. It soon became apparent that the widespread sites were actually a single site, holding the remains of some 10,000 or more adult Maiasaurs. The process of unraveling what could have led to this anomaly and more importantly the implications the discovery has for working out dinosaur behavior, makes for some of the most fascinating reading in the book.
The delight Horner felt at the further discovery of intact eggs from an entirely different species of dinosaur, and then those of another show something of his passion for the work. His constant praise for his various partners and assistants is testament that same passion, in that he is much more interested in sharing the discoveries with the reader than in hoarding the credit.
A true scientist, Horner relates with glee how a colleague in Canada was able to apply Horner's techniques to find the fossils of baby dinosaurs almost in his own back yard.
"We wanted it to be a beginning, to represent a starting point from which we and other paleontologists would go on to find more babies and more nesting grounds, to penetrate more fully the mystery of how the dinosaur babies hatched and grew, of how dinosaurs lived and evolved."
The Science and its Import
In the final chapters, Horner relates how studies of the fossils collected by his team are being used to delve deeper into the question of dinosaur growth, evolution, behavior and the debate surrounding whether or not they were warm or cold blooded. These chapters are the most technical, aside from some jargon filled areas of early chapters that relate to the geological history of the area that Horner was digging in, and present a more traditional view of scientific discovery, that of the lab coat and microscope variety.
"What's important is to look at what the finds meant, what they told us about dinosaurs that we hadn't known before, and what they suggested we might be able to find out about dinosaurs if we just kept looking a bit longer."
Horner's charm lies in his descriptions of fieldwork, though. As important and interesting as the lab work is, the skinned knee, dusty, hardscrabble sections of the book are just that much more fun.
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