Plastron

Plastron

The plastron is the nearly flat part of the shell structure of a turtle or tortoise, what one would call the belly, similar in composition to the carapace; with an external layer of horny material divided into plates called scutes and an underlying layer of interlocking bones.

In certain families there is a hinge between the pectoral and abdominal scutes allowing the turtle to almost completely enclose itself. In certain species the sex of a testudine can be told by whether the plastron is , male or , female. This is because of the mating position.

The plastral scutes join along a central seam down the middle of the plastron. The relative lengths of the seam segments can be used to help identify a species of turtle or tortoise. There are six laterally symmetric pairs of scutes on the plastron: gular, humeral, pectoral, abdominal, femoral, and anal (going from the head to the tail down the seam).

Indicating that the abdominal and gular scute seams are approximately the same length and the femoral and pectoral seams are approximately the same length. Comparison of the plastral formulas provides distinction between the two species.

Turtle plastrons were used by the ancient Chinese in a type of divination called plastromancy. See also oracle bones.

Other Meanings

Plastron is also a name that's been given to various coverings or structures on the ventral (belly) side of some creatures, people or objects.

* "Plastron" is the name of a broad piece of material placed on the chest of certain military uniforms and held in place by two rows of buttons. The plastron was a popular feature of military dress during the period 1800-1914, when it was commonly worn by lancer and uhlan regiments in various European armies. It was also worn by light dragoon regiments in the British Army and by infantry and artillery units in the Imperial Russian Army. Plastrons were usually in contrasting colours to those of the tunics or coats that they were attached to.
* The name of the bulge on an aircraft, such as the Airbus A340, under the fuselage between the wings that is used to correct airflow around the engine pylons. On many aircraft, this bulge also helps house the main undercarriage when retracted.
* A "plastron" is also a thin permanent layer of air around the body of some aquatic insects, held in place by hydrophobic hairs, and acting as a physical gill.
* "Plastron" is also the name of a one-arm, half-jacket used in the sport of fencing.

ee also

* "Plastron" the name of a leading global manufacturer of precision coil bobbins for the electronics industry. Founded in 1970, it is now part of Cosmo Corporation.

Notes


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  • plastron — [ plastrɔ̃ ] n. m. • XVIIe; « armure » 1492; it. piastrone « haubert » 1 ♦ Pièce d armure protégeant la poitrine. Plastron de cuirasse. (XVIIe) Pièce de cuir rembourrée que les escrimeurs portent sur la poitrine. ♢ Zool. Partie ventrale du… …   Encyclopédie Universelle

  • plastron — PLASTRÓN, plastroane, s.n. 1. Partea din faţă apretată (detaşabilă) a unei cămăşi bărbăteşti. ♦ Partea din faţă (detaşabilă) a unei bluze, rochii etc., care constituie o garnitură. 2. Un fel de cravată lată care acoperă pieptul. 3. Bucată de… …   Dicționar Român

  • Plastron — Plas tron, n. [F. plastron breastplate, plastron, LL. plastra a thin plate of metal. See {Plaster}.] 1. A piece of leather stuffed or padded, worn by fencers to protect the breast. Dryden. [1913 Webster] 3. (Anc. Armor) An iron breastplate, worn… …   The Collaborative International Dictionary of English

  • plastrón — m. anat. patol. Zona indurada en un foco inflamatorio. Medical Dictionary. 2011 …   Diccionario médico

  • plastron — (n.) c.1500, from Fr. plastron breastplate, from It. piastrone, augmentative of piastra breastplate, thin metal plate (see PIASTER (Cf. piaster)). As an animal part, from 1813; as an article of dress, 1876 …   Etymology dictionary

  • plastron — plàstrōn m <G plastróna> DEFINICIJA 1. prsni, tvrdi dio košulje 2. ukrasni ušiveni dio košulje ili gornjeg dijela haljine 3. sport zaštitni prsluk mačevaoca na kojem se registriraju udarci ETIMOLOGIJA fr. plastron ← tal. piastrone ≃ piastra …   Hrvatski jezični portal

  • plastron — PLASTRON. s. m. Piece de cuir faite en forme de cuirasse, qui est rembourée & matelassée par dedans, & recouverte de cuir par dessus, & dont les Maistres d armes se couvrent l estomach, lors qu ils donnent leçon à leurs escoliers. Pousser contre… …   Dictionnaire de l'Académie française

  • plastrón — (Del fr. plastron). 1. m. Corbata muy ancha que cubre el centro de la pechera de la camisa. 2. Zool. peto (ǁ de los quelonios) …   Diccionario de la lengua española

  • Plastron — (fr., spr. Plastrong), 1) ein halber Harnisch, Bruststück, welcher nur die halbe Seite des Mannes deckt; 2) bisweilen völliger Küraß; 3) die unteren Schalen der Schildkröten, während das Rückenschild Carapace heißt; 4) Stichblatt …   Pierer's Universal-Lexikon

  • Plastron — (franz., spr. óng), Brustplatte am Ringelpanzer, Brustharnisch; Brustschutz beim Fechten; gestickter Brustteil eines Hemdes etc. In übertragener Bedeutung: Stichblatt, Zielscheibe des Spottes. – Auch die ventrale Platte des Panzers der… …   Meyers Großes Konversations-Lexikon

  • Plastron — (frz., spr. óng), Brustharnisch, Brustleder beim Fechten; breiter Schlips; Stichblatt, Zielscheibe des Spottes …   Kleines Konversations-Lexikon

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