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A rounded elevation of the surface of the tympanic membrane.
(invertebrate zoology)
A prominence above the hinge of a bivalve mollusk shell.



the iron central boss of a shield, which protected the warrior’s hand. Under the hemispherical or conical umbo was a crosspiece by which the shield was held. Shields with umbones were widely used in ancient Greece and Rome and in medieval Europe and Rus’.

References in periodicals archive ?
Larger (greater than 295 [micro]m) specimens in the family Anomiidae (commonly called jingle clams) developed more defined umbones (Fig.
Umbones pequenos, centrales, muy juntos, que se continuan en una linea axial hasta el margen ventral, dividiendo la concha en dos partes muy similares.
In-rolling of the left umbone of pedive-ligers resulted in the umbones being directed at the right angle to the hinge axis, giving rise to the orthogyrous condition (Dinamani 1976).
valdensis (Mantell, 1844) housed in Natural History Museum of London show an identical heart-shape sculpture on the umbones (Fig.