Pachyacanthus Temporal range: Miocene-Pliocene, 15.97–2.588 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Infraorder:	Cetacea
Family:	Platanistidae
Genus:	†Pachyacanthus Brandt, 1871
Species:	†P. suessi
Binomial name
†Pachyacanthus suessi Brandt, 1871

Pachyacanthus is an extinct genus of toothed whale that lived about 15.97 to 2.589 million years ago (Miocene and Pliocene). It contains the single species Pachyacanthus suessi. The genus is known from European deposits in Hungary, Kazakhstan, Austria and Italy.^[1]^[2] The type specimen consisted of a few fragments of a rostrum and two fragmentary tympanic bullae. Skeletons from the Sarmatian (Middle Miocene) of Austria did not include skulls.^[3]

Morphology

The genus is related to modern South Asian river dolphin and is distinguished by pachyostosis in the spinous processes of the postcervical vertebrae.^[4]

Paleoecology

The locations of discovery are thought to have corresponded to well-oxygenated, shallow water sustaining seagrasses similar to today's Mediterranean neptune grass.^[5]

References

^ "†Pachyacanthus suessii Brandt 1871 (toothed whale)". The Paleotological database (PBDB).
^ Domning, Daryl P. (10 Jan 2009). "The readaptation of Eocene sirenians to life in water". Historical Biology. 14, 2000 (1–2): 115–119. doi:10.1080/10292380009380559. S2CID 86603486.
^ "Revision of the genus Pachyacanthus Brandt, 1871 (Mammalia: Cetacea: Odontoceti)". Docplayer.
^ Kazár, Emese (2010-07-12). "E. Kazár. 2010. Revision of the genus Pachyacanthus Brandt, 1871 (Mammalia: Cetacea: Odontoceti)". Annalen des Naturhistorischen Museums in Wien, Serie. 112: 537–567. JSTOR 41701767.
^ Garassino, A.; Pasini, G.; de Angeli, A.; Charbonnier, S.; Famiani, F.; Baldanza, A.; Bizzari, R. (2012). "The decapod community from the Early Pliocene (Zanclean) of "La Serra" quarry (San Miniato, Pisa, Toscana, central Italy): sedimentology, systematics, and palaeoenvironmental implications" (PDF). Annales de Paléontologie. 98 (1): 1–62. Bibcode:2012AnPal..98....1G. doi:10.1016/j.annpal.2012.02.001. ISSN 0753-3969.

Odontocete genera

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea

Odontoceti

†Agorophius †Ankylorhiza †Archaeodelphis †Argyrocetus †Ashleycetus †Caolodelphis †Chilcacetus †Enigmatocetus †Eoplatanista †Inticetus †Macrodelphinus †Microcetus †Mirocetus †Neosqualodon †Olympicetus †Papahu †Patriocetus †Phoberodon †Phococetus †Prosqualodon †Sachalinocetus †Simocetus †Sulakocetus †Tangaroasaurus
†Xenorophidae	Albertocetus Cotylocara Echovenator Inermorostrum Xenorophus
†Waipatiidae	Awamokoa Ediscetus Nihohae Nihoroa Otekaikea Urkudelphis Waipatia
†Squalodontidae	Eosqualodon Squalodon
†Squaloziphiidae	Crisocetus? Squaloziphius Yaquinacetus
†Eurhinodelphinidae	Ceterhinops Eurhinodelphis Iniopsis Mycteriacetus Phocaenopsis Schizodelphis Vanbreenia Xiphiacetus Ziphiodelphis
Crown-Odontoceti	see below↓

Crown-Odontoceti

Physeteroidea

†Acrophyseter †Albicetus †Brygmophyseter †Eudelphis †Hoplocetus †Livyatan †Miophyseter †Rhaphicetus †Scaldicetus †Zygophyseter
Kogiidae	†Aprixokogia Kogia †Koristocetus †Nanokogia †Platyscaphokogia †Pliokogia †Praekogia †Scaphokogia †Thalassocetus?
Physeteridae	†Aulophyseter †Cozzuoliphyseter †Diaphorocetus †Idiophyseter †Idiorophus †Orycterocetus Physeter †Physeterula †Placoziphius †Thalassocetus?

Platanistoidea

†Aondelphis †Dolgopolis †Ensidelphis †Perditicetus †Eurhinodelphinidae? †Squalodontidae? †Waipatiidae?
†Allodelphinidae?	Allodelphis Arktocara Goedertius Ninjadelphis Zarhinocetus
†Squalodelphinidae?	Furcacetus Huaridelphis Macrosqualodelphis Medocinia Notocetus Phocageneus Squalodelphis
Platanistidae	†Araeodelphis †Dilophodelphis †Grimadelphis †Pachyacanthus? Platanista †Pomatodelphis †Prepomatodelphis †Zarhachis?

Ziphiidae

†Aporotus †Beneziphius †Caviziphius †Chavinziphius †Chimuziphius †Choneziphius †Dagonodum †Globicetus †Imocetus †Messapicetus †Nazcacetus †Nenga †Ninoziphius †Notoziphius †Pterocetus Tasmacetus †Tusciziphius †Xhosacetus †Ziphirostrum
Berardiinae	†Archaeoziphius Berardius †Microberardius
Ziphiinae	†Izikoziphius Ziphius
Hyperoodontinae	†Africanacetus Hyperoodon †Ihlengesi Indopacetus Mesoplodon

Delphinida	see below↓

Delphinida

†Albireo †Atocetus †Brevirostrodelphis †Cammackacetus †Delphinodon †Hadrodelphis †Herbeinodelphis †Liolithax †Lophocetus †Macrokentriodon †Miminiacetus †Odobenocetops †Pictodelphis †Pithanodelphis †Tagicetus †Westmorelandelphis
†Kentriodontidae	Belonodelphis? Kampholophos Kentriodon Platysvercus Sophianacetus Rudicetus Wimahl
Lipotidae	Lipotes †Parapontoporia †Prolipotes

Inioidea

†Awadelphis
Iniidae	†Brujadelphis †Goniodelphis Inia †Ischyrorhynchus †Isoninia? †Isthminia †Kwanzacetus †Meherrinia †Plicodontinia †Saurocetes
Pontoporiidae	†Atocetus? †Auroracetus †Brachydelphis †Piscorhynchus †Pliopontos †Pontistes †Protophocaena †Samaydelphis †Scaldiporia †Stenasodelphis Pontoporia

Delphinoidea

Monodontidae	†Bohaskaia †Casatia Delphinapterus †Denebola †Haborodelphis Monodon
Phocoenidae	†Archaeophocaena †Australithax †Haborophocoena †Lomacetus †Miophocaena Neophocaena †Numataphocoena Phocoena Phocoenoides †Piscolithax †Pterophocaena? †Semirostrum †Septemtriocetus

Delphinidae

†Arimidelphis †Australodelphis †Eodelphinus †Etruridelphis †Hemisyntrachelus Lagenorhynchus †Norisdelphis Orcinus †Platalearostrum †Pliodelphis †Pterophocaena?
Lissodelphininae	Cephalorhynchus Lissodelphis
Delphininae	Delphinus Lagenodelphis Sotalia Sousa Stenella Tursiops
Globicephalinae	Feresa Globicephala Grampus Orcaella Peponocephala Pseudorca Steno