plastron

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plas·tron

(plas'tron),
The sternum with costal cartilages attached.
[Fr. a breastplate]

plastron

(plăs′trŏn) [Fr., breastplate]
The sternum and attached cartilages.

plastron

  1. the film of air covering parts of the body in aquatic insects such as water beetles, which enables them to stay under water. The film acts as a gill since gas exchange takes place between the water and the air bubble (plastron respiration).
  2. the horny bridge connecting the sides of the carapace below the body of tortoises and turtles.

plastron

skeletal structure protecting the abdomen of chelonians.
Enlarge picture
Plastron of the tortoise. By permission from Aspinall V, O'Reilly M, Introduction to Veterinary Anatomy and Physiology, Butterworth Heinemann, 2004
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References in periodicals archive ?
In addition, it also shares with the basal members of Eucryptodira from the Late Jurassic of Europe, but not with Xinjiangchelyidae: presence of second and third vertebral significantly broader than the pleurals, presence of central plastral fontanelle.
The presence of foramen caroticum laterale and foramen posterior canalis carotici interni formed by the pterygoid; the presence of wide anterior peripherals; the contact of the axillary buttresses with the costal series; the presence of a short anterior lobe in relation to the plastral bridge; and the absence of lateral plastral fontanelles are not shared with Eurysternidae.
heliostemma); interabdominal seam (of plastral seam formula) longest (unique to R.
heliostemma); plastral seam formula starts with IG>IF>Iab (as in B.
A medium- to large-sized toadhead turtle of the genus Batrachemys that is distinguished from members of other toadhead genera by its large, wide, rounded head; its narrow parietal roof and parieto-squamosal arch; its reduced neural bone series; the combination of its relatively "shallow" carapace, having a median groove, lacking a keel, absence of lateral marginal narrowing, and presence of mild lateral marginal upturning; the presence of a large antero-medial distal tibial scale; and its distinct plastral pattern (see also Appendix Band Fig.
Batrachemys heliostemma is distinguished from its congeners by its distinct head coloration; diminished size of neck tubercles; lack of horizontal line in the iris; greater parietal roof width; its carapace widest at M7; 4th vertebral scute always wider than long; 11th marginals equal to or wider than 12th; mild upturning of lateral marginals; intergular scute narrower than gulars; greater width of the anterior plastral lobe; its plastral seam formula; and its plastral pattern (see Fig.
The two forros share a relatively similar head size and shape, a pointed nose, small barbels, a similar neural bone series, a similar plastral seam formula, lack of keels, a shallow carapace groove, a well-developed distal antero-medial tibial scale, and similar plastral patterns.
The only consistent feature of the plastral seam formula in the specimens studied is that IG>IF> all others.
7c-f)--but especially from P geoffroanus, with which it is partially sympatric) by coloration of the head, carapace and plastron; by the relatively larger size and rounder shape of the head; by the shorter length of the barbels; by its narrower parietal roof and parieto-squamosal arch; by the reduced neural series not touching the proneural; by its plastral seam formula; by its well developed distal tibial scale and by the presence of a mild upturning of its lateral marginal scutes on the carapace.
7h), with which it is partially sympatric, by its head, carapace and plastron coloration; its relatively larger head size and rounder head shape; the narrower parietal roof and parieto-squamosal arch; the reduced features of its neural series; the opposite situation with the gular/intergular width comparisons; the differences in plastral seam formula; the carapacial features of being much flatter, without a keel, and having a median groove; having the 11th marginals equal or wider than 12th marginal pair; having slight lateral marginal upturning; and by a more developed distal antero-medial tibial scale.
Santee: one nuchal, seven costal fragments, six peripherals, three epiplastra, two plastral fragments, UNSM 56965; Devils Nest: one nuchal, three coastal fragments, eight peripherals, one right and one left epiplastron, two entoplastra, one right hyoplastron, 12 plate fragments, UNSM 56909.
one neural, two costal fragments, one left xiphiplastron, two plastral fragments, UNSM 56964.