Hens Teeth

An experimental atavism is something we would produce deliberately. If you can intervene in development of the embryo to produce an ancestral characteristic, that would be an experimental atavism. A very few experimental attempts to achieve this kind of thing have been done. Chicken embryos have been induced to grow teeth. In one case, mouse tissue was transplanted and teeth were produced, so this was not a true atavism, these were not the teeth that we would have seen in an ancestral bird or...

How Feathers Grow

Feathers are one feature, highly pertinent to both avian and nonavian dinosaurs, for which this has been done in elegant and satisfying detail by Richard O. Prum of Yale and several colleagues. Their work is all the more interesting because, in the absence of evidence from genetics and developmental biology, a theory of feather evolution had been developed that seemed to make sense but turned out to be impossible. According to this scenario, Prum and Alan H. Brush wrote in Scientific American...

The Hell Creek Formation

The rocks of what geologists call the Hell Creek Formation are what you see from the road. The formation was named in 1907 by Barnum Brown, a paleontologist from the American Museum of Natural History, based on rock layers near Hell Creek. It is a mixture of sandstone and siltstone that is exposed in Montana, Wyoming, and North and South Dakota. The rock beds that make up the formation vary in thickness, or depth, from 170 meters in Garfield County, where Barnum Brown first identified it, to 40...

The Digging Begins

The first European-American fossil collectors arrived in the West in the middle of the nineteenth century. One early collector in Montana was Ferdinand Hayden. He found a duckbill tooth in the Judith River Formation, from the late Cretaceous, in 1854. This was during the Indian wars, and according to one historical account of the early paleontologists, he acquired an Indian name that suggested the hazards of paleontology at the time, the man who picks up stones while running. Fossils were,...

Feathered Dinosaurs

In the mid-1990s one of the best-preserved dinosaur skeletons ever was found in China, in early Cretaceous sediments that provided an extraordinary record of all sorts of life. Three scientists, Pei-Ji Chen, Shi-ming Dong, and Shuo-nan Zhen reported in Nature in 1997 finding two skeletons of a chicken-sized dinosaur with the longest tail of any theropod dinosaur and a very large and strong first digit, perhaps a killing claw. The preservation was so striking that internal organs and a last meal...

Is It Dangerous

There is a whole range of possible objections that have nothing to do with the health or life conditions of what we could probably call chickenosaurus. And that is fear for the environment, for interfering with the delicate ecological balance of the planet. Many people fear genetically modified crops, for instance, or genetically modified foods. It seems to me that the odds of harm occurring from eating genetically modified foods are very small. There is, of course, always a small chance that...

Acknowledgments

This book would not have been possible without the hard work and dedication of a great many people, foremost among them my former graduate student Dr. Mary Schweitzer, my colleague Dr. Hans Larsson, and former graduate student Chris Organ. A special thanks to each. Other paleontology colleagues whom I've been doing a lot of work with these past few years include Mark Goodwin and Kevin Padian, both of Berkeley, and I owe a debt of gratitude to each. I also thank my staff, including Pat Leiggi,...

Master Genes

It was enough to make a theoretical physicist throw up his hands. And it was the fly that provided the answers. Bithorax was the first of the single-gene mutations in the fly that turned out to be so important in development. The mutation made the hind wings look like the front wings. Others came quickly. A rather spectacular mutant, antennapedia, causes the development of legs in place of the antennae on the head, Carroll wrote. A number of these genes were discovered. They were called...

Dinosaurs Among Us

REX According to our leading scientists, I am not yet extinct, and they ought to know. Well, there's no use crying about it. Will Cuppy, How to Become Extinct Every morning, the dinosaurs make such a racket. I can hear them outside my bedroom window, singing the dawn chorus. When I leave the house they are everywhere. I see them in parks, patrolling the parking lots of shopping malls, on the prairie, along rivers, at the sea, and in New York City, where they...