Mysticeti

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Classis: Mammalia
Subclassis: Theria
Infraclassis: Placentalia
Superordo: Cetartiodactyla
Ordo: Cetacea
Subordo: Mysticeti
Familiae: Balaenidae - Balaenopteridae - †Cetotheriidae - Eschrichtiidae - †Janjucetidae - Neobalaenidae - †Incertae sedis

Name

Mysticeti Flower, 1864

References

* Mysticeti on Mammal species of the World.
* Don E. Wilson & DeeAnn M. Reeder (editors). 2005. Mammal Species of the World : A Taxonomic and Geographic Reference, 2-volume set(3rd ed).

Vernacular names
Internationalization
Dansk: Bardehval
Deutsch: Bartenwale
English: Baleen Whales
Español: Misticetos
Français: Mysticète
Galego: Misticetos
עברית: ליויתני מזיפות
Hrvatski: Kitovi usani
Magyar: Sziláscetek
Italiano: Misticeti
日本語: ヒゲクジラ亜目
Nederlands: Baleinwalvissen
‪Norsk (bokmål)‬: Bardehval
Polski: Fiszbinowce
Português: Baleia
Suomi: Hetulavalaat
Svenska: Bardvalar
Türkçe: Çubuklu balinalar
Українська: Вусаті кити

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The baleen whales, also called whalebone whales or great whales, form the Mysticeti, one of two suborders of the Cetacea (whales, dolphins, and porpoises). Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth. This distinguishes them from the other suborder of cetaceans, the toothed whales or Odontoceti. Living Mysticeti species have teeth only during the embryonal phase. Fossil Mysticeti had teeth before baleen evolved.

The suborder contains four families and fifteen species.
Etymology

The taxonomic name Mysticeti apparently derives from a transmission error in early copies of Aristotle's Historia Animalium in which "ο μυς το κητος" ("the whale known as 'the mouse' or 'Gutter whale' ") was mistakenly run together as "ο μυστικητος" ("the Mysticetus").[2] An alternate name for the suborder is Mystacoceti (from Greek μυσταξ "moustache" + κητος "whale").[3]

Anatomy

Baleen whales are generally larger than toothed whales, and females are bigger than males. This group includes the largest known animal species, the Blue Whale.

Baleen whales have two blowholes, causing a V-shaped blow.

Ecology and life history

Behavioral ecology

Solitary or in small groups.

Breaching

In spite of their enormous size, baleen whales are able to leap completely out of the water. They can grow to 190,000 kilograms (420,000 lb) in weight and 33.5 metres (110 ft) in length.[4] Particularly known for its acrobatics is the Humpback Whale, but other baleen whales also break through the water surface with their body or beat it loudly with their fins. Some believe that the male baleen whales try to show off to the females, to increase their mating success. Scientists speculate that baleen whales and other cetaceans may engage in breaching to dislodge parasites, or scratch irritated skin. Breaching, and other behaviors like lobtailing, are also used to stun or kill nearby fish or krill.

Importance to humans

From the 11th to the late 20th centuries, baleen whales were hunted commercially for their oil and baleen. Their oil was used to make margarine and cooking oils, whilst their baleen was used to stiffen corsets, as parasol ribs and to crease paper.

Evolutionary history

Early baleen whales first appeared as far back as Early Oligocene, or perhaps the latest Eocene (39-29 million years ago; e.g. Llanocetus). Early baleen whales possessed teeth inherited from their ancestors, as opposed to baleen, in modern species. The Oligocene species Aetiocetus cotylalveus is considered the evolutionary link between toothed and baleen whales. It was discovered by renowned fossil collector Douglas Emlong in 1964 near Seal Rock State Recreation Site, Oregon, in a sandstone formation.[5] In the early 1990s, the species Janjucetus hunderi was discovered in Victoria, Australia by a surfer and was described in 2006 by E. M. G. Fitzgerald.[6] Janjucetus was a baleen whale with sharp teeth that hunted fish and squid as well as larger prey, potentially including sharks and dolphin-like cetaceans. These fossils hint that early baleen whales were predatory and eventually evolved into the gentler, toothless whales known today. A recent study identified palatal foramina (bony impressions of blood vessels that 'feed' the baleen racks) in the palate of a toothed mysticete, Aetiocetus weltoni. The scientists involved indicated that this discovery implies that this whale possessed both teeth and baleen, and serves as an intermediate adaptive role between primitive toothed mysticetes and more advanced toothless mysticetes.[7] The first baleen-bearing, toothless baleen whales (such as Eomysticetus, and Micromysticetus) appeared in the late Oligocene.[8] Early baleen whales probably could not echolocate; no anatomical evidence preserved in the skulls and ear regions of any fossil baleen whales show any of the adaptations associated with echolocation as in 'toothed whales' (Odontoceti).[6]

The earliest baleen whale found is called Llanocetus Denticrenatus and it was found on Seymour Island, Antarctica, by Dr. Mitchell in 1989. The species was around in the late eocene, about 45 mya.

References

1. ^ Mead, James G. and Robert L. Brownell, Jr. (16 November 2005). "Order Cetacea (pp. 723-743)". in Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). ISBN 978-0-8018-8221-0. http://www.bucknell.edu/msw3/browse.asp?id=14300002.
2. ^ OED 'mysticete' (n, 1)
3. ^ OED 'mystacocete'
4. ^ Dewey, T.; Fox, D. (2002). "Balaenoptera musculus (On-line)". Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Balaenoptera_musculus.html. Retrieved 2009-06-13.
5. ^ Wallace, D. R. (2007). Neptune's Ark: From Ichthyosaurs to Orcas. Berkeley ; London: University of California Press. ISBN 0-520-24322-6.
6. ^ a b Fitzgerald, E. M. G. (2006). "A bizarre new toothed mysticete (Cetacea) from Australia and the early evolution of baleen whales". Proceedings of the Royal Society - 'B': Biological Sciences, 273 (1604): 2955–2963. doi:10.1098/rspb.2006.3664.
7. ^ Deméré, T., McGowen, M., Berta, A., Gatesy, J. (2008). Morphological and Molecular Evidence for a Stepwise Evolutionary Transition from Teeth to Baleen in Mysticete Whales. Systematic Biology, 57(1), 15-37.
8. ^ A. E. Sanders and L. G. Barnes. 2002. Paleontology of the Late Oligocene Ashley and Chandler Bridge Formations of South Carolina, 3: Eomysticetidae, a new family of primitive mysticetes (Mammalia: Cetacea). Smithsonian Contributions to Paleobiology 93:313-356.

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