There was the famous mistake which E. D. Cope made in 1870 by reconstructing Elasmosaurus with its skull at the tail end of its spine. Altho I must say that this mistake does not well illustrate that it is "ok" to make mistakes as he was hounded by this error for all of his life. Jane Jane P. Davidson PhD University of Nevada Reno fax 702-784-6655 http://home.aol.com/Jdhexen