Explaining Two Different Traditional Estimates of the Generic Diversity of Brachiopods at the Oligocene–Miocene Transition

The present work reconsiders our current knowledge of the presence of brachiopod genera in the Chattian and Aquitanian stages (late Oligocene and Early Miocene, respectively). Two of the most important sources of paleontological information were used. The uncertain presence of taxa in the particular stages was recorded. The results indicated that the total number of brachiopod genera in the Chattian and the Aquitanian was generally the same, irrespective of the chosen dataset. If so, the short-term paleoenvironmental perturbations did not affect the generic diversity of brachiopods. These findings contribute to a better understanding of the presently available, traditional estimates of the generic diversity of brachiopods. However, further critical consideration and improvement of the data and application of some advanced analytical tools is needed.