My favorite of the “transitional” species is Tiktaalik. Just sayin’.
Bob Strauss defines ten of the most important missing links in evolutionary history. These remarkable animals take us from the sea, to land, to the sky; from scales, to feathers, to fur.
The phrase “missing link,” Strauss says, is a bit misleading in the sense that A) they aren’t missing – they have been positively identified in the fossil record; and B) in any particular line of evolution there would not, of course, have been any “missing link.” Hundreds or thousands of “transitional” species likely existed between a fish and a newt.
Here is Bob Strauss’ abridged list; follow the link at the bottom to view the original page with descriptions of each animal.
1. The Vertebrate Missing Link – Pikaia
2. The Tetrapod Missing Link – Tiktaalik
3. The Amphibian Missing Link – Eucritta
4. The Reptile Missing Link – Hylonomus
5. The Dinosaur Missing Link – Eoraptor
6. The Pterosaur Missing Link – Darwinopterus
7. The Plesiosaur Missing Link – Nothosaurus
8. The Therapsid Missing Link – Lystrosaurus
9. The Mammal Missing Link – Megazostrodon
10. The Bird Missing Link – Archaeopteryx
View 10 Missing Links in Vertebrate Evolution on About.com