Involutinida
From Wikipedia, the free encyclopedia
| Involutinida Temporal range: Early Permian- Cenomanian | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Sar |
| Clade: | Rhizaria |
| Phylum: | Retaria |
| Subphylum: | Foraminifera |
| Class: | Tubothalamea |
| Order: | †Involutinida Hohenegger and Piller, 1977 |
| Families | |
Involutinida is an order of foraminifera included in the Spirillinata found in the fossil record from the early Permian to early Late Cretaceous (Cenomanian).
The Involutinida are characterized by a two chambered aragonitic test consisting of an initial spheroidal chamber, or proloculus, enclosed by a tubular second, or main chamber. The test wall may be bilamellar (two layered), the inner layer being microgranular and often dark, the outer hyaline (clear, glassy). Coiling may be planispiral or trochospiral, forming a cone. Lamellar thickenings or pillar-like structures may be found in the umbilical region on one or both sides.[1]
