As I understand it the pictures were literally faked. The same one used for more than one animal.
That is not so. I've got a copy of Haeckel's
Evolution of Man featuring the famous plates. It includes an interesting preface in which Haeckel defends his drawings from his critics (it's a second or third edition I've got). Haeckel argues that they are
diagrams intended to show the salient points and that all diagrams are simplified and therefor inaccurate. I think this is a fair point, open your favourite physics textbook, look up how a CRT works, then take the back off your TV and compare the two. Don't look much alike do they?
The features indicated in Haeckel's drawings do exist in real specimens - although they are not so clear or pronounced as he makes them and his drawings omit various complexities that make the features less obvious in real specimens.
I'd say they fall more under the category of bad illustrations than actual fraud.
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