Verbeekinidae are a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

of large

fusulinacea The Fusulinacea is a superfamily in the Fusulinida in which the test is spherical, discoida, or fusiform; commonly coiled, less often uncoiling in the late stage, numerous chambers per whorl; test wall of microgranular calcite (as for the order) i ...

ns characterized by subspherical, planispirally coiled tests and a long coiling axis. The wall is composed of a dense outer tectum and inner alveolar keriotheca. They are most prominent in Japan and Southeast Asia.https://www.mindat.org/taxon-P113009.html

Lower taxa

As presently defined by ( Loeblich & Tappan, 1988) the Verbeekinidae includes three subfamilies: Verbinkininae, Missellinindae, and Pseudodoliolininae. The family is entirely

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

, with a range from the Wolfcampian (L Perm.) to the

Ochoan The Ochoan is a stage in the Permian stratigraphy (and an age in the geologic timescale) of North America. The Ochoan age is roughly simultaneous with the Changhsingian age in the timescale of the ICS. This post-Guadalupian stage is known for h ...

(U Perm.)

Discussion

In 1964 Loeblich and Tappan included the Verbeekininae (=Verbeekinidae, sensu 1988) and Neoschwagerininae (= Neoschwagerinidae sensu 1988) in the Verbeekinidae.

Treatise A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject and its conclusions."Treat ...

. They defined the Verbeekinidae as having a medium-sized, distinctly fusiform ellipsoid morphology with close-spaced foramina along the base of the septa. A spirotheca (outer wall) composed of tectum and keriotheca was found in early examples of Veebeekinidae, but in later genera may have consisted of a single homogeneous layer. The Verbeekinidae can be equated with the Neoschagerinidae of Cushman. The Verbeekinidae and Neoschwagerinidae are currently distinguished from earlier fusulinaceans, e.g. Fusuninidae and Schwagerinidae, by straight, unfluted or uncorrugated septa, the presence of "I-beam" like transverse, and an axial septula that hang from the spermatheca, partially subdividing the chambers. The septula reinforced the fluted septa rather than corrugated it.

References

* * Alfred R. Loeblich Jr and Helen Tappan,1988. Forminiferal Genera and their Classification. Van Nostrand Reinhold. ''see'
Fusulinina-GSI
* {{Taxonbar, from=Q7920958 Foraminifera families