Vargas AO, Kohlsdorf T, Fallon JF, VandenBrooks J, Wagner GP (2008) The Evolution of HoxD-11 Expression in the Bird Wing: Insights from Alligator mississippiensis. PLoS ONE 3(10): e3325. doi:10.1371/journal.pone.0003325.
This paper, published Oct.3rd, puts another nail in the coffin of the arguments against the dinosaurian origins of birds. One of the biggest arguments used to "disprove" the dino/bird relationship was that, using embryological evidence, birds have digits 2, 3, and 4 on their hands and lost digits 1 and5, but dinosaurs have digits 1, 2, and 3 and lost digits 4 and 5. Morphologically, bird fingers look like digits 1, 2, and 3, just like dinosaur digits. Vargas and crew looked at the activity of the HoxD-11 in crocodiles, birds and mammals. Mammals express HoxD-11 in digits 2-5, but not in 1, crocs express HoxD-11 in digits 2-5, but not in 1. Guess what? Birds express HoxD-11 in digits 2 and 3, but not in digit 1. So birds do not in fact have digits 2, 3, and 4 like the people who disagree with the dino-bird theory. So their biggest argument has now been quite convincingly obliterated. Think we can end this debate now?