Microstructure Analysis Of Miocene Shark Teeth Of Baripada Beds, Odisha, India

Abstract

The present study focuses on the microstructures of Miocene shark teeth of different taxa. For this, samples have been collected from Baripada area, along the river Burhabalang, in the state of Odisha, a place which has undergone global marine transgression in the late Miocene age and yields a good and diverse assemblage of fossils. For the process of analysis, the samples have been polished with corundum powder mixed with one or two drops of water and etched with 2N HCl and acetone. Analysis has been done using Scanning Electron Microscope (SEM) and the results showed that the Chondrichthyan group of sharks has a single homogenous layer known as the Single Crystallite Enameloid (SCE), whereas the Neoselachian group of sharks are more advanced, complex and undergone evolution, comprising of a triple-layered enameloid, namely the Shiny Layer Enameloid (SLE), the Parallel Bundled Enameloid (PBE) and the Tangled Bundled Enameloid (TBE). The study is done to examine different microstructural forms and conduct comparative analysis. In this study, majority of the samples have shown to belong to the Neoselachian group, whilst the remaining few were shown to have Chondricthyan origin. The enameloid in the shark teeth is much harder than the dentin due to the presence of high mineral content and shows a more complex organisation of crystallites at the apical portion of the teeth.