The role of substrate in determining the dominance of immobile, epifaunal bivalves in the Late Cretaceous

Studies of long-term ecological changes are crucial for understanding the factors that govern the distribution and abundance of taxa in time and space. The present study analyses the long-term patterns of palaeoecological changes during the Late Cretaceous, using the marine bivalve fossil record of the Ariyalur Sub-basin, south India. Multivariate quantitative analyses reveal a conspicuous shift in the bivalve palaeocommunity structure from the middle Turonian–Santonian Garudamangalam Formation to the early Maastrichtian Kallankurichchi Formation. A concomitant decline in diversity and evenness from the Garudamangalam to the Kallankurichchi is also associated with a near disappearance of infaunal groups in the latter, where a few stationary epifaunal taxa exhibit overwhelming dominance. Both formations appear to have suffered taphonomic alteration and lithification bias that may have contributed to the reduction of species diversity. The dominance of shallow burrower bivalves in the sil..., , , # **The role of substrate in determining the dominance of immobile, epifaunal bivalves in the Late Cretaceous**

[https://doi.org/10.5061/dryad.z34tmpgph](https://doi.org/10.5061/dryad.z34tmpgph)

## Description of the data and file structure

**Primary Dataset**: The dataset includes all taxonomic and abundance data of all species across 44 samples. The 'Ecospace code of species (Tiering-Motility-Feeding Mode)' of all species and the sources of information (for ecospace codes) are also included.  

**Sample description**: This file contains the stratigraphic description (Formation, Member, and Unit) of each of the 44 samples included in the Primary Dataset. Information about the dominant mode of tiering and motility of each sample is also included in this file.

**List of references**: This file contains the list of references used to determine the ecospace code of each species included in the Primary Dataset.

## Sharing/Access information

Data was derived from the following sources:...,