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

Kaiika maxwelli, a new Early Eocene archaic penguin (Sphenisciformes, Aves) from Waihao Valley, South Canterbury, New Zealand

(2011) RE Fordyce et al.   NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS

Multiple cenozoic invasions of Africa by penguins (Aves, Sphenisciformes)

(2011) D. T. Ksepka et al.   PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES

Aspects of Diversity in Early Antarctic Penguins

(2010) Piotr Jadwiszczak et al.   ACTA PALAEONTOLOGICA POLONICA

Penguin heat-retention structures evolved in a greenhouse Earth

(2010) D. B. Thomas et al.   Biology Letters

The Basal Penguin (Aves: Sphenisciformes) Perudyptes devriesi and a Phylogenetic Evaluation of the Penguin Fossil Record

(2010) Daniel T. Ksepka et al.   BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY

Fossil Evidence for Evolution of the Shape and Color of Penguin Feathers

(2010) J. A. Clarke et al.   SCIENCE

Osteology ofIcadyptes salasi, a giant penguin from the Eocene of Peru

(2008) Daniel T. Ksepka et al.   JOURNAL OF ANATOMY

A Phylogenomic Study of Birds Reveals Their Evolutionary History

(2008) S. J. Hackett et al.   SCIENCE