Verbeekinidae

Verbeekinidae
Scientific classification
Domain: Eukaryota
Kingdom: Rhizaria
Superphylum: Retaria
Phylum: Foraminifera
Order: Fusulinida
Superfamily: Fusulinacea
Family: Verbeekinidae
Van Möller
subfamilies

see text

Verbeekinidae are large fusulinaceans characterized by subspherical to cylindral, planispirally coiled tests; long axis the coiling axis. Wall is composed of a dense outer tectum and inner, alveolar keriotheca.

Lower taxa

As presently defined (Loeblich & Tappan, 1988) the Verbeekinidae includes three subfamilies, the Verbinkininae, Missellinindae, and Pseudodoliolininae. The family is entirely Permian, with a range from the Wolfcampian (L Perm.) to the Ochoan (uU Perm.)

Discussion

Loeblich and Tappan, 1964, in the Treatise, included the Verbeekininae (=Verbeekinidae, sensu 1988) and Neoschwagerininae (= Neoschwagerinidae sensu 1988) in the Verbeekinidae as then perceived. Defined the Verbeekinidae as having a shell of medium size, spherical, ellipsoidal to elongate ellipsoidal, or distinctly fusiform, with close spaced foramina along the base of all septa; spirotheca (outer wall) composed of tectum and keriotheca in early members but in later genera may consist of a single homogenous layer. The Verbeekinidae (1964) can be equated with the Neoschagerinidae of Cushman, 1950

The Verbeekinidae and Neoschwagerinidae, as now perceived, are set apart from earlier fusulinaceans, e.g. Fusuninidae and Schwagerinidae, by straight, unfluted or uncorregated, septa and by the presence of "I-beam" like transverse and axial septula that hang from the spirotheca, partially subdividing the chambers. The septula rather than corregated or fluted septa provide a reinforcing.

References

This article is issued from Wikipedia - version of the Sunday, January 18, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.