hyponomic sinus उदाहरण वाक्य
उदाहरण वाक्य
- "' Hemiphragmoceratidae "'is a family of endogastrically brevconic oncocerids characterized by elaborately visored apertures in which the hyponomic sinus in mature specimens is on a spout-like process and there may be lateral and dorsal salients . ( Sweet 1964, Flower 1950 ).
- The family has its beginning with the Middle Silurian " "'Protophragmoceras " "', known from a gradually and evenly expanding endogastric shell with an unrestricted aperture, like that of ts cyrtogomphoceratid ancestors, deep sharp hyponomic sinus for the water-jet funnel, and ventral siphuncle, phragmoceratid in character.
- Growth lines are sinuous, show a pronounced hyponomic sinus in the coiled juvenile portion at the apex but almost none at the mature aperture of the orthcone . " Holmiceras " is similar except that its whorls are more loosely coiled and it is known only from the Arenigian whereas " Ancistroceras " ranges through most of the Middle Ordovician.
- Members of the Poterioceratidae are distinguished by a subcircular to compressed exogastric shell ( curved upwardly so as the lower side, the venter, is convex viewed from the side ) that has no hyponomic sinus and a central to subcentral siphuncle composed of subquadrate to nummuloidal segments in which the septal necks are more strongly curved on the upper, or dorsal side.
- Oocerina differs primarily in having an actinosiphonate siphuncle composed of numuloidal ( beaded ) segments . " "'Paroocerina " "'( K288 ), named by Zhurevleva in 1961, is a slender oncoceratid from the Middle and Upper Silurian of eastern Europe and ex-USSR ( Russia ), similar to " Oocerina ", but with a hyponomic sinus.