Horopeta is a genus of baleen whale from the Late Oligocene (Chattian) Kokoamu Greensand of New Zealand.
| Horopeta Temporal range: Late Oligocene,
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| Restoration of Horopeta | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | incertae sedis |
| Genus: | †Horopeta Tsai and Fordyce, 2015 |
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Description
editHoropeta can be distinguished from other balaenomorphs in the following characters: base of frontal sloping moderately from skull midline; parietal considerably exposed at sagittal crest; parietal largely exposed at sagittal crest; unfused and short posterior process of periotic and tympanic bulla; prominent superior process of periotic; presence of elliptical foramen and sigmoidal cavity in tympanic bulla; unfused and short posterior processes of periotic and tympanic bulla; a distinct pedicle plate situated in fovea epitubaria; presence of horizontal cleft, elliptical foramen, and sigmoidal cavity in tympanic bulla.[1]
Classification
editInitial cladistic analysis recovered Horopeta as either a basal balaenomorph or a basal cetotheriid, although the describers noted that the juvenile nature of the holotype might influence its cladistic position within Chaeomysticeti. Later cladistic analyses corroborated the placement of Horopeta outside crown Mysticeti.[1][2][3]
Paleobiology
editBased on the structure of the jaw, Horopeta was one of the earliest chaeomysticetes capable of gulp-feeding as in extant mysticetes.[1] The same deposits that yielded Horopeta have also yielded the primitive odontocetes Awamokoa, Austrosqualodon, Otekaikea, and Waipatia, the eomysticetids Matapanui, Tohoraata, Tokarahia, and Waharoa, and the balaenomorphs Mauicetus and Whakakai.
References
edit- ^ a b c Cheng-Hsiu Tsai; R. Ewan Fordyce (2015). "The Earliest Gulp-Feeding Mysticete (Cetacea: Mysticeti) from the Oligocene of New Zealand". Journal of Mammalian Evolution 22 (4): 535–560. doi:10.1007/s10914-015-9290-0.
- ^ Tsai, C.H., Fordyce R.E., 2016. Archaic baleen whale from the Kokoamu Greensand: earbones distinguish a new late Oligocene mysticete (Cetacea: Mysticeti) from New Zealand. Journal of the Royal Society of New Zealand. doi:10.1080/03036758.2016.1156552
- ^ Carlos Mauricio Peredo; Mark D. Uhen (2016). "A new basal chaeomysticete (Mammalia: Cetacea) from the Late Oligocene Pysht Formation of Washington, USA". Papers in Palaeontology. Online edition. doi:10.1002/spp2.1051