Tetrapod ichnology is a powerful tool to reconstruct the faunal composition of Middle Triassic ecosystems. However, reconstructions based on a single palaeoenvironment provide an incomplete and impoverished picture of the actual palaeodiversity. In this paper, we analyse Middle Triassic tetrapod ichnoassociations from the detrital Muschelkalk facies of the Catalan Basin of northeast Spain, ranging from terrestrial to coastal settings. We identified two main tetrapod ichnoassociations, preserved in two different palaeoenvironments, comprising the following ichnogenera and morphotypes: Procolophonichnium, Chelonipus, Rhynchosauroides, Rotodactylus, Chirotherium, Isochirotherium, Sphingopus, and indeterminate chirotheriids. We also statistically analyse a database of all known Middle Triassic tetrapod footprint localities worldwide; this database includes, for each track locality, the precise age, the palaeoenvironment and the presence/absence of ichnotaxa. Our results on the composition of ichnofauna within the palaeoenvironments of the Catalan Basin are integrated into this database. This approach allows us to revisit the palaeoenvironmental bias linked to the marine transgression that affected the Western Tethys region. Tetrapod ichnoassociations reveal the following palaeoenvironmental patterns: (1) in coastal settings, ichnoassociations are Rhynchosauroides-dominated and diversity is relatively low; (2) in terrestrial settings and those with less marine influences, ichnoassociations are non-Rhynchosauroides-dominated, usually characterised by more abundant chirotheriid tracks and, generally, a higher track diversity. The correlation between tetrapod ichnoassociations and sedimentary facies reveals how palaeoenvironmental constraints influenced faunal assemblages, especially those of the Middle Triassic of the Western Tethys region. Ichnoassociations allow the ecological response of tetrapod faunas to the environmental changes to be inferred for this critical time interval. Marine transgressions strongly influenced tetrapod ecosystems: environmental conditions were key for the faunal recovery in the aftermath of the end-Permian extinction, with the settlement of the so-called modern faunas and the rise of the dinosaur lineage.

四足动物学是重建中三叠纪生态系统动物区系组成的有力工具。然而，基于单个古环境的重建提供了一个不完整且贫困的实际古生物图景。在本文中，我们分析了来自西班牙东北加泰罗尼亚盆地碎屑Muschelkalk相的中三叠纪四足动物鱼类联合体，范围从陆地到沿海。我们确定了两个主要的四足动物ichnoassociations，在两个不同的古环境保存完好，包括以下ichnogenera和形态：Procolophonichnium，Chelonipus，Rhynchosauroides，Rotodactylus，Chirotherium，Isochirotherium，Sphingopus以及不确定的手性疗法。我们还对全球所有已知的中三叠纪四足动物足迹地区进行数据库分析；该数据库包括针对每个轨道位置的确切年龄，古环境和鱼鳞生物的存在/不存在。我们对加泰罗尼亚盆地古环境中鱼类动物组成的研究结果已整合到该数据库中。这种方法使我们能够重新审视与影响西特提斯地区的海侵有关的古环境偏见。四足动物的鱼类协会揭示了以下古环境模式：（1）在沿海地区，鱼类协会是Rhynchosauroides-主导，多样性相对较低；（2）在陆地环境和海洋影响较小的地区，鱼鳞协会是非Rhynchosauroides为主，通常以更丰富的手性赛道为特征，并且通常具有更高的赛道多样性。四足动物的鱼类与沉积相之间的相关性揭示了古环境限制如何影响动物群落，特别是西特提斯地区中三叠纪的动物群落。鱼类协会允许在此关键时间间隔内推断四足动物对环境变化的生态反应。海洋侵害极大地影响了四足动物的生态系统：环境条件是二叠纪末期灭绝后动物群恢复的关键，伴随着所谓的现代动物群的建立和恐龙世系的兴起。