Take Haeckel’s embryos. Similar figures comparing embryos are found in all textbooks, usually as drawings to make the relevant features clear. The figures compring embryos are there, for the simple reason that embryos of vertebrates are very similar, as can be seen from good photographs too. It takes some time to collect good photographs from the diverse literature on embryological studies on vertebrates – one at a time – but it is totally against fact to deny embryo similarity.