Transitional fossil

When Charles Darwin's Origin Of Species was first published, the fossil record was poorly known, and the claim that there was a lack of transitional fossils was perfectly reasonable. However, the discovery of Archeopteryx only two years later was seen as a stunning triumph for Darwin's theory of common descent. Similarly, O.C. Marsh provided groundbreaking evidence of transitional fossils in the evolution of horses. Since that time, many more transitional fossils have been found. Where transitional fossils are "missing," their absence is explained by the genetic diversity of a particular species and the punctuated equilbrium that occurs within the context of that particular species.