# Discriminating conodont recording bias: a case study from the Nanzhang-Yuan’an Lagerstätte

## TL;DR

This study examines how fossilization processes affect conodont preservation in a Chinese lagerstätte, revealing biases that could impact paleobiological interpretations.

## Contribution

The study identifies and quantifies conodont recording bias caused by preservation and acid-dissolving methods, highlighting the impact on paleobiological interpretations.

## Key findings

- Conodont elements show biased preservation based on morphology, with larger individuals more prone to destruction.
- Acid-dissolving procedures increased preservation bias, affecting all conodont elements.
- P elements of Ellisonidae were least affected, while S elements were most affected by preservation bias.

## Abstract

The Early Triassic Nanzhang-Yuan’an Lagerstätte of Hubei Province, South China, preserves abundant marine reptiles in the uppermost part of the Jialingjiang Formation and provides detailed insights into marine organisms, including newly discovered and well preserved conodont clusters of the Family Ellisonidae. These conodont elements allow us to assess the bias introduced during the acquisition process. We examined conodont elements preserved on the bedding planes and those acquired after the acid-dissolving method to analyze their attributes and length distributions. We identified a biased preservation of different conodont elements related to their morphologies. After the acid-dissolving procedures, the bias increased, and all different elements were affected, with larger individuals being particularly prone to destruction. Among them, the P elements of Ellisonidae were the least affected, while the S elements were the most affected. This study further indicates that paleobiological interpretations based on fossil size or morphology could be obscured if the influence of post-mortem effect is ignored.