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Faunal realms in Jurassic and Cretaceous belemnites

G. R. Stevens
Faunal realms in Jurassic and Cretaceous belemnites
Geological Magazine (1964) 100 (6): 481-497


The extent and characteristics of three faunal realms that can be recognized for Jurassic and Cretaceous belemnites are given here in summarized form accompanied by eight world maps showing occurrence and migration routes. The Boreal and Tethyan realms parallel Arkell's realms for Jurassic ammonites, but no equivalent for the ammonite Pacific realm has been discerned for the belemnites. They apparently are divided, partly in the Boreal and partly in the Indo-Pacific. The boundary between the Boreal and Tethyan realms was a distinct and stable one, probably influenced by climate. The boundary between the Tethyan and Indo-Pacific realms varied considerably in the upper Jurassic and lower Cretaceous. It is postulated that belemnite migration must have been subject to some form of control, which could have been that, while free swimmers themselves, their prey was confined to shelves and therefore deep-water areas would be barriers. In the discussion statements on delimitation of realms, influence of barriers on migration, and temperature effects are challenged.

ISSN: 0016-7568
EISSN: 1469-5081
Coden: GEMGA4
Serial Title: Geological Magazine
Serial Volume: 100
Serial Issue: 6
Title: Faunal realms in Jurassic and Cretaceous belemnites
Author(s): Stevens, G. R.
Pages: 481-497
Published: 1964
Text Language: English
Publisher: Cambridge University Press, London, United Kingdom
Accession Number: 1964-004889
Categories: Invertebrate paleontology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: sketch maps, 1963; discussion, by R. Bowen, v. 101, No. 4, p. 374-376
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Update Code: 1964
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