CT scanned skull of holotype. Sequiwaimanu rosieae is the fourth penguin species from the Waipara Greensand, which has previously yielded two species assigned to the genera Muriwaimanu and Waimanu. The original specimen is within the collections of the Canterbury Museum (accession number CM 2016.6.1). The total length of the preserved portion of the skull is 211.0 mm. The length of upper beak from the nasofrontal hinge to the preserved tip is 143.1 mm.