Rostrum (anatomy)

In anatomy, the term rostrum (from the Latin rostrum meaning beak) is used for a number of phylogenetically unrelated structures in different groups of animals.

Bottlenose Dolphin KSC04pd0178 head only
The rostrum (beak) of a bottlenose dolphin


Washington DC Zoo - Macrobrachium rosenbergii 6

Crustacean: the rostrum of the shrimp Macrobrachium rosenbergii is serrated along both edges.

Gminatus australis with Beetle

Insect: assassin bug piercing its prey with its rostrum

Architeuthis beak

Cephalopod: the two-part beak of a giant squid


Wolf cranium labelled
Diagram of a wolf skull with key features labelled

In mammals, the rostrum is that part of the cranium located in front of the zygomatic arches, where it holds the teeth, palate, and nasal cavity.[6]

The beak or snout of a vertebrate may also be referred to as the rostrum.

Istiophorus platypterus

Sailfish, like all billfish, have a rostrum (bill) which is an extension of their upper jawbone

Paddlefish Polyodon spathula

The paddlefish has a rostrum packed with electroreceptors

Sawfish genova

Sawfish have an electro-sensitive rostrum (saw) which is also used to slash at prey

See also


  1. ^ Charles Drew (November 17, 2003). "Crustacea". University of Bristol. Retrieved November 7, 2010.
  2. ^ Todd A. Haney, Joel W. Martin & Eric W. Vetter (2007). "Leptostraca". In James T. Carlton. The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon (4th ed.). University of California Press. pp. 484–495. ISBN 978-0-520-23939-5.
  3. ^ George Gordh, Gordon Gordh & David Headrick (2003). "Rostrum". A Dictionary of Entomology. CAB International. p. 792. ISBN 978-0-85199-655-4.
  4. ^ Douglas Grant Smith (2001). "Mollusca (gastropods, pelecypods)". Pennak's freshwater invertebrates of the United States: Porifera to Crustacea (4th ed.). John Wiley and Sons. pp. 327–400. ISBN 978-0-471-35837-4.
  5. ^ Burt Carter. "Cephalopods". Invertebrate Paleobiology.
  6. ^ Elbroch, Mark "Animal Skulls: A Guide to North American Species", Stackpole Books 2006, p9
  7. ^ "Basic anatomy of Cetaceans - Dolphins". Robin's Island. Archived from the original on November 17, 2010. Retrieved November 7, 2010.
  8. ^ Wueringer BE, Squire Jr L, Kajiura SM, Hart NS and Collin SP (2012) "The function of the sawfish's saw" Current Biology, 22 (5): R150-R151. doi:10.1016/j.cub.2012.01.055

The beak, bill, and/or rostrum is an external anatomical structure of birds that is used for eating and for preening, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young. The terms beak and rostrum are also used to refer to a similar mouth part in some ornithischians, pterosaurs, turtles, cetaceans, dicynodonts, anuran tadpoles, sirens, pufferfishes, billfishes and cephalopods.

Although beaks vary significantly in size, shape, color and texture, they share a similar underlying structure. Two bony projections—the upper and lower mandibles—are covered with a thin keratinized layer of epidermis known as the rhamphotheca. In most species, two holes known as nares lead to the respiratory system.

Beak (disambiguation)

A beak is an anatomical structure of birds, which serves as the mouth and jaws.

Beak may also refer to:

Beak, a type of molding

Barnell Bohusk, a Marvel Comics character formerly known as Beak

Beak, a Beanie Buddy kiwi bird

Beak (botany), a pointed projection on various parts of plants

Beak, an old-fashioned slang term for the headmaster of a school or a magistrate

Beak, slang term for the drug cocaine

Beak (band), a music group formed by Geoff Barrow, Billy Fuller, and Matt Williams

Beak Island, in the Prince Gustav Channel

A member of the teaching staff at Charterhouse School or Harrow School

Beak (bivalve), the oldest point of a shell of a bivalve mollusc

Cephalopod beak

Beak (album)


The neuraxis or sometimes neuroaxis is the axis of the central nervous system. It denotes the direction in which the central nervous system lies. During embryological development, the neuraxis is bent by various flexures, contributing to the mature structure of the brain and spinal cord.

Embryonic development can help in understanding the structure of the adult brain because it establishes a framework on which more complex structures can be built. First, the neural tube establishes the anterior–posterior dimension of the nervous system, which is called the neuraxis. The embryonic nervous system in mammals can be said to have a standard arrangement. Humans (and other primates, to some degree) make this complicated by standing up and walking on two legs.

The anterior–posterior dimension of the neuraxis overlays the superior–inferior dimension of the body. However, there is a major curve between the brain stem and forebrain, which is called the cephalic flexure. Because of this, the neuraxis starts in an inferior position—the end of the spinal cord—and ends in an anterior position, the front of the cerebrum. This may be confusing, and can be illustrated when looking at a four-legged animal standing up on two legs. Without the flexure in the brain stem, and at the top of the neck, that animal would be looking straight up instead of straight in front.


Rostrum may refer to:

Any kind of a platform for a speaker:



Australian Rostrum, an association of Australian public speaking clubs

Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects

Rostrum (ship), a form of bow on naval ships

Rostrum of corpus callosum, a commissural fiber

Rostrum Records, an American record label

The Rostrum, the official monthly magazine of the National Forensic League

International Rostrum of Composers

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