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Oligocene-Miocene ostracode assemblages with the genus Palmoconcha from Japan

Tatsuhiko Yamaguchi and Takahiro Kamiya
Oligocene-Miocene ostracode assemblages with the genus Palmoconcha from Japan
Journal of Paleontology (July 2007) 81 (4): 632-642


The genus Palmoconcha in the family Loxoconchidae of Ostracoda is found in Cenozoic sediments from the North Pacific. The genus Palmoconcha from the North Pacific is divided into two morphological groups: One is the P. parapontica characterized by having a prominent murus along a posterodorsal margin. Another is the P. laevimarginata group characterized by the nonprominent murus. Both the P. parapontica and P. laevimarginata groups contain six species including a new species and six species, respectively. The P. parapontica group is distributed in only northwestern Pacific, whereas the P. laevimarginata group occurs in both the western and eastern sides of the North Pacific. The assemblages occupied by the P. parapontica group, together with Acanthocythereis, Falsobuntonia, and Robertsonites occur from deposits of Japan during the middle Miocene and the early Oligocene climatic cooling. They associate with temperate molluscan faunas, and are considered to have appeared in shelf environments under temperate realms around the Japanese Islands during the Oligocene and Miocene climatic cooling. Four species including three new species from the Oligocene Waita Formation are also described.

ISSN: 0022-3360
EISSN: 1937-2337
Serial Title: Journal of Paleontology
Serial Volume: 81
Serial Issue: 4
Title: Oligocene-Miocene ostracode assemblages with the genus Palmoconcha from Japan
Affiliation: Niigata University, Department of Geology, Niigata, Japan
Pages: 632-642
Published: 200707
Text Language: English
Publisher: Paleontological Society, Lawrence, KS, United States
References: 82
Accession Number: 2007-065523
Categories: Invertebrate paleontology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. strat. cols., 2 tables, geol. sketch maps
N33°55'60" - N33°55'60", E130°41'60" - E130°41'60"
Secondary Affiliation: Kanazawa University, JPN, Japan
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, Copyright, The Paleontological Society. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 200733
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