Late Scythian–Anisian ostracods (Crustacea) from the Meged-2 borehole, central Israel

Avraham Honigstein,Sylvie Crasquin

doi:10.1144/0262-821x10-022

Abstract

Abstract. Cutting samples from the Zafir Formation in the Meged-2 well (5013–5200 m), central Israel, were examined for ostracods. Seventeen species, belonging to eleven genera, could be distinguished. Five of them are described here as new species: Bairdia megedensis nov. sp., Bairdia bariudini nov. sp., Renngartenella ragilis nov. sp., Renngartenella perii nov. sp. and Patellacythere ephraimi nov. sp. Six species of the genera Renngartenella, Mostlerella and Kerocythere may also represent new taxa, but were left in open nomenclature, due to their rare occurrence in the samples. Only one species has been reported from other localities. Punctate forms of the genus Bairdia and Paracypris sp. are the most common species in the samples. The ostracods indicate a normal open-marine environment of deposition. The ostracod assemblages point to a Late Scythian–Anisian age, confirmed by foraminiferal and palynological data, but this age assignment remains disputed until the new taxa described here have been independently dated.

Highlights

The Late Permian mass extinction was the greatest during Phanerozoic times
The ostracod assemblages point to a Late Scythian–Anisian age, confirmed by foraminiferal and palynological data, but this age assignment remains disputed until the new taxa described here have been independently dated
MATERIAL AND METHODS Twenty-seven samples of the 5013–5200 m section of the Meged-2 well were examined for ostracods

Summary

INTRODUCTION

The Late Permian mass extinction was the greatest during Phanerozoic times. The Permian–Triassic boundary is the most important turnover in the evolution of ostracods. A change from Palaeozoic to ‘Meso-Cenozoic’ forms is clearly recorded at this period In detail this transformation was not abrupt (Crasquin-Soleau et al, 2007). Few data are recorded on Early Triassic and Anisian age ostracods. The Meged structure is an inverse Early Mesozoic fault structure, folded during the Syrian Arc folding events in the Late Cretaceous–Oligocene. Triassic sediments occur in northern and central Israel only in a few borehole sections, but reach thicknesses of several kilometres. In northern Israel, the lower part of the Triassic section appears to be in a rather uniform micrite and pelmicrite lithology (Benjamini et al, 2005). Korngreen & Benjamini (2011: table 2) attribute these sediments in the Meged-2 section tentatively to the Anisian Gevanim Formation In northern Israel, the lower part of the Triassic section appears to be in a rather uniform micrite and pelmicrite lithology (Benjamini et al, 2005). Korngreen & Benjamini (2011: table 2) attribute these sediments in the Meged-2 section tentatively to the Anisian Gevanim Formation

Wuchiapingian First representatives ofMesozoicforms

MATERIAL AND METHODS

Holotype Paratype

RESULTS AND DISCUSSION

Ostracods in British Stratigraphy