During the P-Tr transition, trace fossil metrics exhibit distinct patterns across environmental settings. In brackish environments, all metric trajectories demonstrate a marked decline from the Griesbachian to Dienerian, rise during the early Smithian, and then diminish slightly across the Smithian-Spathian boundary (Figs. 4.1 and 4.2 ). For carbonate ramp settings, all indices experienced a sharp decline during the P-Tr extinction event, stabilized at reduced levels through the late Griesbachian–Dienerian, reached a peak in the late Smithian, and subsequently saw a minor downturn (Figs. 4.3 and 4.4 ). In carbonate platform settings, metrics underwent moderate declines during the P-Tr extinction, remained subdued through the late Griesbachian–Dienerian, rose in the early Smithian, and ultimately surpassed pre-extinction values to establish a prominent plateau towards the early Spathian (Figs. 4.5 and 4.6 ). By contrast, lower shoreface facies sections display an inverse trend to carbonate platforms (Figs. 4.7 and 4.8 ). Within shelf-slope to basin settings, all metrics displayed rebounds during the early and late Griesbachian, culminating in significant recovery by the early Smithian (Figs. 4.9 and 4.10 ). These patterns indicate that behavioral variations among burrowing fauna during the P-Tr interval show environment-dependent selectivity. Post-extinction, infaunal behavioral and ecological diversity recovered locally in deeper settings (shelf-slope-basin, lower shoreface) during the early and late Griesbachian, with marine environments achieving full recovery by the early Smithian.