czerkas cover Dinosaurs, Mammoths, and Cavemen:
                             The Art of Charles R. Knight, 1982
By Sylvia Massey Czerkas and Donald F. Glut.

I picked up this excellent book several years ago at the Maryland Book Exchange in College Park Maryland.  This volume is a
must-have as it contains numerous copies of Charles R. Knights paintings and drawings of prehistoric animals--both well known and
obscure.   A majority of the illustrations are in full color.  This includes all of the murals produced for the Chicago Field Museum of Natural History,
the complete series of color illustrations that Knight prepared for an article in the National Geographic magazine in 1942 (the cover
illustration of the battling tyrannosaurs is one of them), and many many others. 


Knight's first published restoration of Stegosaurus as it appeared in McClure's Magazine in 1897.

   mosasaurus    1.
tylosaurus from mix 2.    osborn

The color painting above (1) is a dynamic 1899 restoration of a Tylosaurus that is contained in Czerkas and Glut.  This is one of my favorite
Knight paintings.  The Tylosaurus and the turbulent water is executed realistically and beautifully.  Compare this image of Tylosaurus with
the monochromatic version (2) that is reproduced in Jennie Irene Mixs' Mighty Animals published in 1912.   Besides the additional turbulent
water contained in the foreground of the "Mix" version, there are some other subtle differences (compare the two jumping fish, for example). 
The last example (3) is from H. F. Osborn's "The Origin and Evolution of Life, published in 1918.  This time, the jumping fish are different
again!  Also note that version number 1 reveals the artist's signature and date (1899) in the lower right hand corner (it is hard to see in the
scan, but it is there in orange).  Version number 3 also shows a signature, albeit truncated and at a lighter tone.  There is no signature to be
found on version number 2.  Are they all separate paintings, or are they the same painting, cropped and retouched by Knight at a later date? 

Added 8/2/09:

Special thanks to paleoartist Dan Varner for clearing up the mystery of the Tylosaurus painting.  According to Dan (personal communication):

"First, disregard the second of the three images. That's just a poorly retouched and enlarged version by some other artist for a book illustration
made long after Knight's images. It's just bad and confusing.   Two events happened at the turn of the last century. First, Henry Fairfield
Osborn purchased the "Bourne" specimen of Tylosaurus, a superb specimen, for the American Museum of Natural History. Secondly, Samuel
Williston described a skeleton of another mosasaur, also from Kansas. Both specimens showed dermal-like features in the neck region.
Williston interpreted these as being a kind if frill running down the neck region much like the present day iquana. Osborn upon hearing this
had Chas R Knight add this feature to his wonderful restoration. This is when Knight's painting was photographed by the museum for
eproduction purposes. It's the image that has been reproduced hundreds of times, I'm sure, and the one we all grew up on.   But back in
Kansas, Williston realized he had errored. It turned out that those peculiar features were the displaced cartillaginous rings of the trachea. He
corrected himself in a little-known paper (see: ). Williston must have contacted Osborn
about the situation and Knight corrected the painting, removing the "mane" and, at the same time updating the fish (although they were still
in error). Problem is no photo was taken of the corrected painting and the old image was still used until _Dinosaurs, Mammoths and
Cavemen_ was published in the 1980's."

You know I never even noticed the mane was missing from the Czerkas and Glut version!