New late Eocene and Oligocene remains of the flightless, penguin-like plotopterids (Aves, Plotopteridae) from western Washington State, U.S.A.

Oligocene plotopterid skulls from western North America and their bearing on the phylogenetic affinities of these penguin-like seabirds

(2015) Gerald Mayr et al.   JOURNAL OF VERTEBRATE PALEONTOLOGY

Ecology and Caudal Skeletal Morphology in Birds: The Convergent Evolution of Pygostyle Shape in Underwater Foraging Taxa

(2014) Ryan N. Felice et al.   PLoS One

Whole-genome analyses resolve early branches in the tree of life of modern birds

(2014) E. D. Jarvis et al.   SCIENCE

New fossil penguins (Aves, Sphenisciformes) from the Oligocene of New Zealand reveal the skeletal plan of stem penguins

(2012) Daniel T. Ksepka et al.   JOURNAL OF VERTEBRATE PALEONTOLOGY

Fossil Plotopterid Seabirds from the Eo-Oligocene of the Olympic Peninsula (Washington State, USA): Descriptions and Functional Morphology

(2011) Gareth J. Dyke et al.   PLoS One

Reassessment of the Zemorrian foraminiferal Stage and Juanian molluscan Stage north of the Olympic Mountains, Washington State and Vancouver Island

(2010) Elizabeth A. Nesbitt et al.   NEWSLETTERS ON STRATIGRAPHY

Phylogenetic Analysis of Pelecaniformes (Aves) Based on Osteological Data: Implications for Waterbird Phylogeny and Fossil Calibration Studies

(2010) Nathan D. Smith   PLoS One

A Phylogenomic Study of Birds Reveals Their Evolutionary History

(2008) S. J. Hackett et al.   SCIENCE