Rasmussen was also involved in a review of fossil birds from Miocene and Pliocene deposits in North Carolina. Finds included an early Miocene loon "Colymboides minutus", various ducks, a crested tern closely resembling the modern royal tern "Sterna maxima", and a member of the crow genus, one of the few fossil passerine birds from that period. The review found that fossil birds from this period generally closely resemble a modern species or genus, and those that do not can usually be placed in a modern family with a fair degree of confidence.