Editing Cetacea (section)

=== Head ===
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|image1=Beluga premier.gov.ru-1.jpeg
|caption1=Head profile of a [[beluga whale]], featuring the large "melon" region

|image2=SBNMS - feeding humpback whale (31319806616).jpg
|caption2=Close up of a feeding [[humpback whale]], showing baleen

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Whales have an elongated head, especially [[baleen whales]], due to the wide overhanging jaw. Bowhead whale plates can be {{convert|9|m|ft}} long. Their nostril(s) make up the [[Blowhole (anatomy)|blowhole]], with one in toothed whales and two in baleen whales.<ref>{{Cite journal|last1=Buono|first1=Mónica R.|last2=Fernández|first2=Marta S.|last3=Fordyce|first3=R. Ewan|last4=Reidenberg|first4=Joy S.|date=2015|title=Anatomy of nasal complex in the southern right whale, Eubalaena australis (Cetacea, Mysticeti)|journal=Journal of Anatomy|language=en|volume=226|issue=1|pages=81–92|doi=10.1111/joa.12250|issn=1469-7580|pmc=4313901|pmid=25440939}}</ref>

The nostrils are located on top of the head above the eyes so that the rest of the body can remain submerged while surfacing for air. The back of the skull is significantly shortened and deformed. By shifting the nostrils to the top of the head, the nasal passages extend perpendicularly through the skull.<ref name="Klima1999">{{cite book|author=Milan Klima |title=Development of the Cetacean Nasal Skull|url=https://books.google.com/books?id=kOHAz9SCL54C |date=29 January 1999 |publisher=Springer |isbn=978-3-540-64996-0 }} {{page needed|date=April 2018}}</ref> The teeth or baleen in the upper jaw sit exclusively on the [[maxilla]]. The braincase is concentrated through the nasal passage to the front and is correspondingly higher, with individual cranial bones that overlap.{{citation needed|date=October 2024}}

In toothed whales, connective tissue exists in the [[melon (cetacean)|melon]] as a head buckle. This is filled with air sacs and fat that aid in buoyancy and [[biosonar]]. The sperm whale has a particularly pronounced melon; this is called the [[spermaceti organ]] and contains the eponymous [[spermaceti]], hence the name "sperm whale". Even the long tusk of the narwhal is a vice-formed tooth. In many toothed whales, the depression in their skull is due to the formation of a large melon and multiple, asymmetric air bags.<ref>{{Cite journal |last1=Cranford |first1=Ted W. |last2=Amundin |first2=Mats |last3=Norris |first3=Kenneth S. |date=1996 |title=Functional morphology and homology in the odontocete nasal complex: Implications for sound generation |url=https://onlinelibrary.wiley.com/doi/10.1002/(SICI)1097-4687(199606)228:3%3C223::AID-JMOR1%3E3.0.CO;2-3 |journal=Journal of Morphology |language=en |volume=228 |issue=3 |pages=223–285 |doi=10.1002/(SICI)1097-4687(199606)228:3<223::AID-JMOR1>3.0.CO;2-3 |pmid=8622183 |issn=1097-4687}}</ref>

[[River dolphin]]s, unlike most other cetaceans, can turn their head 90°. Most other cetaceans have fused neck vertebrae and are unable to turn their head at all.{{citation needed|date=October 2024}}

The [[baleen]] of baleen whales consists of long, fibrous strands of keratin. Located in place of the teeth, it has the appearance of a huge fringe and is used to sieve the water for [[plankton]] and krill.<ref>{{Cite web |title=What is baleen? |url=https://us.whales.org/whales-dolphins/what-is-baleen/ |access-date=2025-01-13 |website=Whale & Dolphin Conservation USA |language=en-US}}</ref>