Written in Stone: Evolution, the Fossil Record, and Our Place in Nature

This area produces a protein given the whimsical name Sonic Hedgehog,

If an organised body is not in the situation and circumstances best adapted to its sustenance and propagation, then, in conceiving an indefinite variety among the individuals of that species, we must be assured, that, on the one hand, those which depart most from the best adapted constitution, will be most liable to perish, while, on the other hand, those organised bodies, which most approach to the best constitution for the present circumstances, will be best adapted to continue, in preserving themselves and multiplying the individuals of their race.

In order to approximate dinosaurian physiology, the trio of scientists carried out the unenviable task of sticking thermometers in the cloacae of American alligators.

the difficulties of making temperature experiments [on fully grown alligators] would be great and can be best left to the imagination.”)

Distinguishing the first true birds from their feathered dinosaur relations has become increasingly difficult. If we define birds as warm-blooded, feathered, bipedal animals that lay eggs, then many coelurosaurs are birds, so we have to take another approach.

As new discoveries continued to accumulate it became apparent that almost every group of coelurosaurs had feathered representatives, from the weird secondarily herbivorous forms such as Beipiaosaurus to Dilong, an early relative of Tyrannosaurus. It is even possible that, during its early life, the most famous of the flesh-tearing dinosaurs may have been covered in a coat of dino-fuzz.

The places paleontologists looked for fossils and how those fossils have been interpreted have been influenced by politics and culture, reminding us that while there is a reality that science allows us to approach the process of science is a human endeavor.