''Kupoupou'' (meaning "diving bird" in Ta Rē Moriori) is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

from the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

-aged Takatika Grit of the

Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about te ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

which is believed to be the oldest penguin genus known to date. The type species, ''K. stilwelli'', was named and described by Blokland ''et al.'' in 2019.

Discovery and naming

Five specimens are known and they were excavated between 2006 and 2011 and the group that excavated the specimens was led by

Monash University Monash University () is a public research university based in Melbourne, Victoria, Australia. Named for prominent World War I general Sir John Monash, it was founded in 1958 and is the second oldest university in the state. The university h ...

palaeontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Jeffrey Stilwell, who is honoured in the epithet of ''K. stilwelli''. The holotype is NMNZ S.47312; an associated left tarsometatarsus, left radius, and caudal vertebra, and the referred material consists of: *NMNZ S.44729; a left coracoid. *NMNZ S.47303; associated partial skeleton comprising a distal right carpometacarpus, left radius, proximal right radius, right proximal phalanx of the second digit, right phalanx of the third digit, an almost complete axis, four cervical vertebrae, a caudal vertebra, a left rib, and a partial worn ilium *NMNZ S.47308; a right femur, a left humerus, a sternal section of a left coracoid, a left ulna. *NMNZ S.47339; omal part scapula, distally eroded left humerus, right ulna, right radius, distal left femur, distal left tibiotarsus, two cervical vertebrae and five other vertebrae in differing degrees of preservation and exposure at the rock surface, and two partial ribs.

Description

Blokland ''et al.'' (2019) estimated that when fully grown, ''Kupoupou'' grew to around tall on average. Similar to modern penguins, ''Kupoupou'' was best suited to an aquatic lifestyle. It was also the first

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

penguin found to be similar in both hind limb and foot shape to modern penguins.

Classification

Blokland ''et al.'' placed ''Kupoupou'' as the oldest and most basal member of the

Sphenisciformes Penguins (order Sphenisciformes , family Spheniscidae ) are a group of aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapt ...

and they also identified that the ancestors of penguins, the Aequornithes (known as core water birds), probably diverged from the lineage leading to their closest living relatives, such as albatrosses (Diomedeidae) and

petrels Petrels are tube-nosed seabirds in the bird order Procellariiformes. Description The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group (all except the albatross f ...

(

Procellariiformes Procellariiformes is an order (biology), order of seabirds that comprises four family (biology), families: the albatrosses, the Procellariidae, petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still call ...

), during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

(early

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval ...

; around 70 Ma) and then diverged into many different species after the K-Pg mass extinction event happened 66 million years ago.

References

{{Taxonbar, from=Q94143199 Fossil taxa described in 2019 Extinct birds of Oceania Bird genera Paleocene birds Sphenisciformes