Molecular evolution and expression of archosaurian β‐keratins: Diversification and expansion of archosaurian β‐keratins and the origin of feather β‐keratins

The archosauria consist of two living groups, crocodilians, and birds. Here we compare the structure, expression, and phylogeny of the beta (β)‐keratins in two crocodilian genomes and two avian genomes to gain a better understanding of the evolutionary origin of the feather β‐keratins. Unlike squamates such as the green anole with 40 β‐keratins in its genome, the chicken and zebra finch genomes have over 100 β‐keratin genes in their genomes,...