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

Kaiika maxwelli is a new species of archaic fossil penguin from the Kauru Formation (Waipawan-Mangaorapan, Early Eocene) of the southern Canterbury Basin, Waihao River, South Canterbury, New Zealand. Kaiika maxwelli is represented by a well-preserved large and robust humerus, in which the broad m. scapulotricipitalis tendon sulcus, sigmoidal shaft and vestigial supracondylar process are similar to those of the basal penguin Waimanu, but differs from Waimanu and other penguins by having a deeply incised ventral tubercle and a smoothly curved profile of the deltoid crest and head. Humeral length suggests a body length of 1.3 m comparable to that of an emperor penguin, indicating that large penguins lived at a time of global warmth. This is the first significant fossil penguin named from pre-Bortonian (Middle Eocene) strata of the southern Canterbury Basin. Kaiika maxwelli is only the seventh species of fossil penguin reportedly older than Middle Eocene.