The genus Clavulinoides Cushman emended and the new Cretaceous genus Clavulinopsis

Abstract
The type species and other Paleocene species of the genus Clavulinoides Cushman, 1936, have simple apertures and canaliculate walls and are distinct from both Clavulina d''Orbigny, 1826, of the Tertiary (with canaliculate walls, apertural tooth and toothplate) and CLAVULINOPSIS gen. nov. [type species C. hofkeri sp. nov.] of the Late Cretaceous (with canaliculate walls and a sieve-like aperture). All are distinct from the Cretaceous genus Tritaxia Reuss, 1860, with its simple aperture, internal toothplate and solid walls, and from the Cretaceous-Tertiary Pseudoclavulina (Cushman) with its solid walls and simple aperture. The significance of iterative, independent development of canalicular walls is discussed.

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