References
Articles behind a paywall are accessible for free from some universities and libraries. In any case, you can usually get at least an abstract.
Ahlberg PE, Clack JA, Luksevics E, Blom H, Zupins I (2008) Ventastega curonica and the origin of tetrapod morphology. Nature 453(7199): 1199–1204 (paywall, figures).
Anderson JS, Reisz RR, Scott D, Frobisch NB, Sumida SS (2008) A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders. Nature 453(7194): 515-518 (paywall, figures).
Apesteguia S, Hussam Z (2006) A Cretaceous terrestrial snake with robust hindlimbs and a sacrum. Nature 440(7087): 1037-1040 (paywall, figures).
Benton MJ (2005) Vertebrate Palaeontology, 3rd edition. Oxford: Blackwell Publishing.
Clack JA (2002) An early tetrapod from 'Romer's Gap'. Nature 418(6893): 72-76 (paywall, figures).
Clack JA (2005) Getting a Leg Up on Land. Scientific American 293(6): 100-107 (online).
Coyne JA (2009) Why Evolution is True. Oxford: Oxford University Press.
Dawkins R (2009) The Greatest Show on Earth: The Evidence for Evolution. London: Bantam Press.
Evans WE (1992) Horse Breeding and Management. New York: Elsevier Science.
Florida Museum of Natural History (date unknown) Dinohippus (online).
Forster CA, Chiappe LM, Krause DW, Sampson SD (1996) The first Cretaceous bird from Madagascar. Nature 382(6591): 532-534 (paywall).
Friedman M (2008) The evolutionary origin of flatfish asymmetry. Nature 454(7201): 209-212 (paywall, figures).
Futuyma DJ (2005) Evolution. Sunderland: Sinauer.
Gibbons A (2009) A New Kind of Ancestor: Ardipithecus Unveiled. Science 326(5949): 36-40 (free reg required).
Gingerich PD, Arif M, Clyde WC (1995) New Archaeocetes (Mammalia, Cetacea) from the Middle Eocene Domanda formation of the Sulaiman range, Pun Jab (Pakistan). Contributions from the Museum of Paleontology, The University of Michigan 29(11): 291-330 (online).
Gingerich PD, Ul-Haq M, Zalmout IS, Khan IH, Malkani MS (2001) Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan. Science 293(5538): 2239-2242 (paywall, data).
Gingerich PD, Ul-Haq M, Von Koenigswald W, Sanders WJ, Smith BH, Zalmout IS (2009) New Protocetid Whale from the Middle Eocene of Pakistan: Birth on Land, Precocial Development, and Sexual Dimorphism. PLoS ONE 4(2): e4366 (online).
Hu D, Hou L, Zhang L, Xu X (2009) A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus. Nature 461(7264): 640-643 (paywall, figures).
Jenkins FA, Walsh DM (1993) An Early Jurassic caecilian with limbs. Nature 365(6443): 246-250 (paywall).
Lu J, Unwin DM, Jin X, Liu Y, Ji Q (2009) Evidence for modular evolution in a long-tailed pterosaur with a pterodactyloid skull. Proceedings of the Royal Society B (online).
Macdonald DW (ed.) (2009) The Encyclopedia of Mammals, 3rd edition. Oxford: Oxford University Press.
MacFadden BJ (1986) Fossil Horses from "Eohippus" (Hyracotherium) to Equus: Scaling, Cope's Law, and the Evolution of Body Size. Paleobiology 12(4): 355-369 (paywall).
Niedzwiedzki G, Szrek P, Narkiewicz K, Narkiewicz M, Ahlberg PE (2010) Tetrapod trackways from the early Middle Devonian period of Poland. Nature 463(7277): 43-48 (paywall, figures).
Prothero DR (2007) Evolution: What the Fossils Say and Why It Matters. New York: Columbia University Press.
Prothero DR (2008) What missing link? New Scientist 197(2645): 35-41 (paywall).
Rak Y, Ginzburg A, Geffen E (2007) Gorilla-like anatomy on Australopithecus afarensis mandibles suggests Au. afarensis link to robust australopiths. Proceedings of the National Academy of Sciences 104(16): 6568-6572 (online).
Raven PH, Johnson GB, Losos JB, Mason KA, Singer SR (2008) Biology, 8th edition. New York: McGraw Hill.
Ridley M (2004) Evolution, 3rd edition. Oxford: Blackwell Publishing.
Romer AS (1969) Cynodont Reptile with Incipient Mammalian Jaw Articulation. Science 166(3907): 881-882 (paywall).
Senter P (2006) Scapular orientation in theropods and basal birds, and the origin of flapping flight. Acta Palaeontologica Polonica 51(2): 305-313 (online).
Thewissen JGM, Williams EM, Roe LJ, Hussain ST (2001) Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature 413(6853): 277-281 (paywall, figures).
Thewissen JGM, Cooper LN, George JC, Bajpai S (2009) From Land to Water: the Origin of Whales, Dolphins, and Porpoises. Evo Edu Outreach 2(2): 272-288 (online).
Thewissen JGM, McLellan WA (2009) Maiacetus: displaced fetus or last meal? PLoS ONE (online).
Van Valen L (1968) Monophyly or Diphyly in the Origin of Whales. Evolution 22(1): 37-41 (paywall).
White TD, Asfaw B, Beyene Y, Haile-Selassie Y, Lovejoy CO, Suwa G, WoldeGabriel G (2009) Ardipithecus ramidus and the Paleobiology of Early Hominids. Science 326(5949): 75-86 (free reg required).
Xu X, You H, Du K Han F (2011) An Archaeopteryx-like theropod from China and the origin of Avialae. Nature 475: 465-470 (paywall).
Yates AM, Bonnan MF, Neveling J, Anusuya C, Blackbeard MG (2009) A new transitional sauropodomorph dinosaur from the Early Jurassic of South Africa and the evolution of sauropod feeding and quadrupedalism. Proceedings of the Royal Society B (online).
Zimmer C (1998) At the Water's Edge: Macroevolution and the Transformation of Life. New York: Free Press.