Biology:Kairuku
| Kairuku | |
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| Artist's impression of Kairuku | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Sphenisciformes |
| Genus: | †Kairuku Ksepka, Fordyce, Ando & Jones, 2012 |
| Type species | |
| Kairuku waitaki Ksepka, Fordyce, Ando & Jones, 2012
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| Species | |
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Kairuku is an extinct genus of penguin.[1] It contains three species, K. grebneffi, K. waitaki [2] and K. waewaeroa.[3] This taxon is known from bones from 27 MYA (late Oligocene), from the Kokoamu Greensand Formation of New Zealand.[1] It was historically referred to as Palaeeudyptes.[1]
Etymology
The genus name Kairuku comes from the Māori words kai (“food”) and ruku (“to dive”).[1]
The species name waewaeroa is from Māori waewae - "legs", and roa - "long", referring to the elongated hind limbs.[3]
K. grebneffi was named after Andrew Grebneff, a paleontologist from the University of Otago who died in 2010.[4]
Distribution
The fossils of Kairuku waewaeroa were found within the Glen Massey formation (34.6–27.3 Ma) in the North Island of New Zealand.[3]
Description
Kairuku is one of the most completely known genus of Paleogene penguins. Described species are larger than modern emperor penguin which stood around a meter,[1] K. grebneffi stood 1.28 metres (4.2 ft) tall,[1] and K. waewaeroa is even larger with height up to 1.38 metres (4.5 ft).[3] Unnamed species called Glen Murray fossil penguin is estimated to have a height 2 to 20% taller than K. grebneffi.[5]
Kairuku grebneffi
Kairuku grebneffi were nearly 1.5 metres (4.9 ft) long and stood 1.3 metres (4.3 ft) tall.[4] Adult individuals weighed an estimated 60 kilograms (130 lb), 50% more than modern emperor penguins.[6] K. grebneffi had the longest humerus bone of any penguin extant or attested to in the fossil record.[4] The bird had a longer bill and more slender body compared to living penguins.[7] Relative to its body size, its flippers were longer and probably more flexible than those of extant species.[7][8] The bird had short, thick legs, but overall, looked much like a modern penguin "from a distance."[7][8] K. grebneffi is distinguished from its sister species K. waitaki primarily on the basis of vertebrae spacing and by having a straight tipped bill, compared to the curved tip of K. waitaki.[4] Additionally, all known specimens of K. grebneffi are larger, although small sample size prevents that from being a diagnostic characteristic.[4]
K. grebneffi likely used its slender beak to spear fish and squid.[7] It likely was able to dive deeper and swim farther than living penguins.[6] Predators of the bird likely included sharks and Squalodons.[7]
K. grebneffi lived in what is now New Zealand late in the Oligocene period, roughly 25-27 million years ago.[6] At the time, most of the area was ocean, with a few isolated islands.[6] It is believed that these rock outcrops provided safe breeding grounds and easy access to rich food resources in the surrounding seas.[6] K. grebneffi lived alongside at least four other penguin species. It is likely that each species fed on different kinds of fish.[9]
K. grebneffi was among of the last of the giant penguins.[7] The cause of K. grebneffi's extinction is unknown, but was probably related to "the drastic change in paleoenvironment" according to Tatsuro Ando, one of the scientists who classified the penguin.[7] Other possibilities include the arrival of new predators and increased food competition.[6]
Kairuku waewaeroa
The skeleton of the holotype is one of the most complete skeletons of giant penguins that have ever been found. Phylogenetic analysis reveals a clade that unites[clarification needed] New Zealand endemics Kairuku waewaeroa, Kairuku waitaki and Kairuku grebneffi. The probable height of K. waewaeroa is 1.38 m (4.5 ft), and the length of the body from the fingertips to the tip of the beak is 1.6 m (5.2 ft).[3][10]
Discovery
The first Kairuku bones were discovered in 1977 by Ewan Fordyce, although they were not identified as such at the time.[6][11] In February 2012, an international team of scientists led by Fordyce and Daniel Ksepka reconstructed a K. grebneffi skeleton using a few "key specimens" from the Kokoamu Greensand of the North Otago and South Canterbury districts of New Zealand.[4][6] The specimens used represent some of the most complete skeletons found of any extinct penguin, and thus provide valuable insight into the reconstruction of all extinct penguins.[4] The king penguin was used as a guide during reconstruction.[6]
The holotype of K. grebneffi was collected in 1991 from a drainage area of the Waipati stream, a tributary of the Maerewhenua River.[4]
Fossil remains of Kairuku waewaeroa, or Kawhia giant penguin, fossil remains were found in Kawhia Harbour on the North Island of New Zealand.[3][12]
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Ksepka, Daniel T.; Fordyce, R. Ewan; Ando, Tatsuro; Jones, Craig M. (March 2012). "New fossil penguins (Aves, Sphenisciformes) from the Oligocene of New Zealand reveal the skeletal plan of stem penguins". Journal of Vertebrate Paleontology 32 (2): 235–254. doi:10.1080/02724634.2012.652051.
- ↑ Giant Prehistoric Penguin was Bigger Than an Emperor | Observations, Scientific American Blog Network
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Giovanardi, Simone; Ksepka, Daniel T.; Thomas, Daniel B. (2021-09-16). "A giant Oligocene fossil penguin from the North Island of New Zealand". Journal of Vertebrate Paleontology 41 (3): e1953047. doi:10.1080/02724634.2021.1953047.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Ksepka, Daniel T.; Fordyce, R. Ewan; Ando, Tatsuro; Jones, Craig M. (March 2012). "New fossil penguins (Aves, Sphenisciformes) from the Oligocene of New Zealand reveal the skeletal plan of stem penguins". Journal of Vertebrate Paleontology 32 (2): 235–254. doi:10.1080/02724634.2012.652051.
- ↑ Thomas, DB; Ksepka, DT (2016-10-01). "The Glen Murray fossil penguin from the North Island of New Zealand extends the geographic range of Kairuku". Journal of the Royal Society of New Zealand 46 (3–4): 200–213. doi:10.1080/03036758.2016.1211541. ISSN 0303-6758. https://doi.org/10.1080/03036758.2016.1211541.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 "Scientists reconstruct 'elegant' giant penguin that lived in New Zealand 26 million years ago". Dawn. Associated Press. March 1, 2012. https://www.dawn.com/news/699376/scientists-reconstruct-extinct-giant-penguin.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Viegas, Jennifer (February 27, 2012). "Ancient Penguin Weighed 130 Pounds". Discovery News (Discovery Channel). http://news.discovery.com/animals/penguin-tallest-fattest-new-zealand-120227.html.
- ↑ 8.0 8.1 "Fossils show huge penguin once roamed New Zealand". Bangkok Post. Agence France-Presse. February 28, 2012. https://www.bangkokpost.com/world/282011/fossils-show-huge-penguin-once-roamed-new-zealand.
- ↑ Dell'Amore, Christine (February 27, 2012). "Giant Prehistoric Penguins Revealed: Big but Skinny". National Geographic News. https://www.nationalgeographic.com/animals/article/120227-new-giant-penguins-species-science-ksepka-new-zealand.
- ↑ "A mega-penguin stood tall on prodigious limbs". Nature 597 (7878): 597. 2021-09-21. doi:10.1038/d41586-021-02562-y. https://www.nature.com/articles/d41586-021-02562-y.
- ↑ "Kairuku - a new "giant" Late Oligocene Penguin from New Zealand". University of Otago. https://www.otago.ac.nz/geology/research/paleontology/otago067613.html.
- ↑ Wetzel, Corryn (2021-09-17). "New Zealand Kids Discovered This Fossil of New Giant Penguin Species on a Field Trip". Smithsonian Magazine. https://www.smithsonianmag.com/smart-news/kids-discover-fossil-of-new-giant-penguin-species-180978707/. Retrieved 2021-09-19.
External links
Wikidata ☰ Q2247912 entry
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