T191 Stratigraphic Paleobiology: Working with the Nature of the Stratigraphic Record to Address Paleobiological Questions

Tuesday, 11 October 2022
1:30 PM - 5:30 PM
Mile High Ballroom 4B

FIRST RECORD OF SEEBACHIA BRONNI FROM THE LATE TITHONIAN OF KUTCH, INDIA AND ITS PALEOBIOGEOGRAPHIC IMPLICATIONS

Paper number: T191-16
Program: Technical Sessions
Time: 5:10 PM – 5:25 PM

Authors

Abstract

Paleobiogeographic distribution is an important parameter to shape the Earth’s biotic composition and subsequently grab interest among paleontologists. The upper Tithonian of Kutch is restricted in the western part of India. Seebachia bronni is reported from the upper Tithonian of Kutch, western India. All three genera of Seebachia are present in the Late Jurassic of Kutch, India. The morphological characters are used to differentiate between three species of the genus Seebachia. Morphological character analysis shows the overlapping of characters between S. elongata and S. sowerbyana, and S. bronni shows significantly different characteristics. S. bronni has been reported from Africa and Madagascar until recently. Indian occurrence of S. bronni Krauss, 1850 sheds light on the marine connection among these regions during the late Tithonian. Species diversification of the late Tithonian is found in sediments deposited in Maximum Flooding Zone. Occurrences of S. bronni in India suggest limited latitudinal distribution restricted the species in the lower latitude (14ºS to 45ºS) of southern hemisphere. The two subgenus of Seebachia shows overlapping geographic region from the Late Jurassic onwards, after the occurrence of subgenus Seebachia (Seebachia) in the Madagascar in the Oxfordian stage. During the Early Jurassic, prior to the occurrence of another subgenus S.(S.), Seebachia (Eoseebachia) was restricted in the higher latitudes of the southern hemisphere (80.13ºS, New Zealand) which confirms the existence of Gondic corridor from the Early Jurassic onwards. Occurrence of S. (S.), in the Late Jurassic stage, changed the geographic positional affinity of S. (E.) from higher latitude to lower latitude and subsequently the genus Seebachia (along with two subgenera Seebachia and Eoseebachia) became endemic to the Ethiopian Faunal Province. The thermophilous nature of these bivalve genera restricted their distribution to the lower latitude in the southern hemisphere.

Geological Society of America Abstracts with Programs. Vol. 54, No. 6

doi: 10.1130/abs/2022AM-378164

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