Appendix C The fossils and the rocks Missing links in the fossil record Gould advocates the theory of ‘punctuated equilibrium’ which says that changes in species arrived suddenly without gradual transition (that is, ‘a dinosaur laid an egg of a creature with wings—the ancestor of a bird’). Though this theory is no better than classical gradualism advocated by Darwin, at least Gould acknowledged the lack of transitional forms in the fossil record when he wrote: The family trees which adorn our text