Verbeekinidae
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.
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| Family: | Verbeekinidae Van Möller |
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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
- Loeblich, Alfred R.; Tappan, Helen (1964). Moore, R.C. (ed.). Protista 2: Sarcodina Chiefly "Thecamoebians" and Foraminiferida. Treatise on Invertebrate Paleontology. C (5th ed.). Geological Society of America. ISBN 978-0-8137-3003-5.
- Alfred R. Loeblich Jr and Helen Tappan,1988. Forminiferal Genera and their Classification. Van Nostrand Reinhold. see Fusulinina-GSI
- Cushman, Joseph A. (2013). Foraminifera, their classification and economic use (4th ed.). Harvard University Press. ISBN 978-0674330856.