By: Peter O. Baumgartner, Robin Liechti and Luis O'Dogherty
Radiolaria are a marine siliceous microplankton group that existed since the Cambrian to the Recent. Fossil Radiolaria were known since the middle of the last Century and intensely studied at the beginning of the 20th Century. Intense biostratigraphic radiolarian research was spurted by the Ocean Dilling Project in the 1970ties, and has proven to be fundamental for the understanding of the geology of Tethyan and Circumpacific mountain ranges. Today, Radiolaria are an important microfossil group used worldwide to date Paleozoic, Mesozoic and Cenozoic rocks.
This database contains the INTERRAD Jurassic-Cretaceous Working Group
(1995) radiolarian database with the systematics, sample database, and
the UAZ95 biochronology. It also includes the Middle Cretaceous
radiolarian biochronology and palaeontology from Northern Apennines and
Betic Cordillera by O’DOGHERTY (1994).
The various datasets are related in a way to easily access and visualise ranges of selected taxa, ranges of all taxa of a sample, or taxa of a selected time interval. The base is designed for repeated update by members of the working group with editing privileges: New taxa can be introduced, old taxa can be edited, images can be withdrawn or moved to other taxa and new ones can be uploaded. Revised data sets can be published or left in preview mode to be revised by other members of the working group before publishing.
The published portions of this database are accessible by submitting a request for an account, while the unpublished data sets are accessible via username/password to members of the working group with editing privileges.
The original volume published by the INTERRAD Jurassic-Cretaceous Working Group in 1995 was the result of a collaborative effort of 32 contributors from 12 countries. It gives a synthesis the systematic, occurrences, and biochronology of Middle Jurassic (Aalenian) to Lower Cretaceous (early Aptian) Radiolaria from the Tethys and other ancient low-latitude realms.
In INTERRAD Jurasssic-Cretaceous database the systematics of 151 genera, 424 species and 41 subspecies is treated. Radiolarian occurrences are reported from more than 1400 samples from more than 170 localities in the Central Atlantic, Europe, Russia, The Middle East, Japan, Northern and Central Pacific, and Western North and Central America. More than 450 species and subspecies from over 60 localities including 800 samples were used to construct a zonation by means of Unitary Associations. Each of the 22 new Unitary Association Zones are defined by characteristic taxa or pairs of taxa that co-occur in the zone. These zones are correlated to the standard stages by means of other fossils reported from the same sections, such as ammonites, nannofossils, calpionellids and dinoflagellates, as well as by means of paleomagnetic and stable isotope stratigraphy established in the same sections.
The Middle Cretaceous radiolarian biochronology and palaeontology by O’DOGHERTY (1994) gives the systematics and synonymy of 303 species and 76 genera that are recorded in 600 samples form 7 sections in the Northern Apennines and the Betic Cordillera, spanning the Aptian to Cenomanian time interval. The biochronology of O’DOGHERTY (1994) will be accessible on-line at a later stage.