The skeletal system of a male Humboldt Penguin(Spheniscus humboldti) was described in details.It’s characterized by the following:bones are heavy and not pneumatic;bill is elongated and heavy,with the anterior end curving downward slightly;scapula is greatly extended;thoracic vertebrae are free;keel is prominent;forelimb specializes as a "flipper" and all skeletons are flattened;mobility of the intrinsic wing is restricted;first metacarpus and first manual digit disappear;patella large and strong;tarsometatarsus short and flat.These features are mainly designed for underwater flight and upright stand.