This is Open Access week. For now at least, all Royal Society content is open access.
Nicholas R. Chan (2017)
Morphospaces of functionally analogous traits show ecological separation between birds and pterosaurs.
Proceedings of the Royal Society B 2017 284 20171556
Shane O'Reilly, Roger Summons, Gerald Mayr & Jakob Vinther (2017)
Preservation of uropygial gland lipids in a 48-million-year-old bird.
Proceedings of the Royal Society B 2017 284 20171050