Orbitolina
Extinct genus of foraminifera
Orbitolina is an extinct genus of foraminifera belonging to the order Textulariida and family Orbitolinidae. Fossils of this genus are widely found in beds deposited in the Tethys Ocean ranging from Aptian (early Cretaceous) to Cenomanian (early Late Cretaceous) in age. It has been used as a shallow carbonate platform facies marker and as a Cretaceous index fossil.
The test of the organism has the shape of a cone, with the proloculus (initial chamber) at the apex of the cone and increasingly large cuplike chambers forming the remainder of the test. Each chamber is further subdivided by numerous partitions.
Sources and credits
This article is adapted from the Wikipedia article “Orbitolina”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Canyon Lake Gorge March 2017 Foraminifera Fossils.jpg by Larry D. Moore, CC BY 4.0
Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.