NEW ASSOCIATED SKELETON OF ARCHAEOSPHENISCUS (SPHENISCIFORMES: SPHENISCIDAE) FROM THE KOKOAMU GREENSAND (CHATTIAN, LATE OLIGOCENE) OF NEW ZEALAND

A new fossil penguin specimen from the Late Oligocene (Chattian; NZ stage: Duntroonian) of New Zealand is referred to the genus Archaeospheniscus. The extinct penguin remains of a single individual were found in the Waitaki area within South Canterbury of the South Island. The specimen is from the Kokoamu Greensand formation, a glauconitic sandstone, indicative of a sediment-starved, shallow marine depositional setting. Invertebrate fossils found within the associated greensand include bivalves, brachiopods, gastropods, and abundant foraminifera. Vertebrate fossils found within the unit include penguins and cetaceans. Although several species have been named from this bed alone, recovered skeletal remains of fossil penguins are rare, and like modern penguins, they are only found in the southern hemisphere. This associated specimen is at least 50% complete.

Skeletal elements include coracoid, humerus, radius, ulna, metacarpals, manual phalanx, vertebra, synsacrum, femur, tibiotarsus, fibula, pedal phalanx, and a partial scapula; some of this material may represent previously unknown elements for Archaeospheniscus. The humerus and tarsometatarsus are the two most diagnostic skeletal elements used in identification for this genus. Although the tarsometatarsus is not present, preliminary identification has been made based on the humerus. The humerus and other elements exhibit diagnostic characters closely matching those of the type specimen of Archaeospheniscus (A. lowei). Limb proportions of the humerus to the femur, however, and morphological characters of the ulna do not match with those of the two previously described species from New Zealand, A. lowei and A. lopdelli. These characteristics may indicate that this specimen is a new species.