Eifelian (Middle Devonian) to Early Frasnian (Late Devonian) conodonts and strata in the Spanish Central Pyrenees: Global correlations and effects of climatic fluctuations in the biota

Abstract

The interval between the late Eifelian and early Frasnian was marked by significant paleoenvironmental instability, including major evolutionary, eustatic, and biotic events. This study analyzes conodont diversity and evolutionary dynamics in the Givetian of the Spanish Pyrenees, using integrated quantitative and qualitative methods, and focusing on responses to global Devonian paleoenvironmental events. Key global events are examined for their impact on conodont communities. Results show a steady rise in diversity peaking in the ansatus Zone, which saw the highest evolutionary turnover, followed by a decline into the latifossatus Zone. Origination generally outpaced extinction until this point. Major faunal changes correlate with the Taghanic and Geneseo events, while the Kačák and Lower pumilio events had limited regional effects. The Upper pumilio and Frasnes events influenced diversification. The findings underscore periodic biodiversity shifts, driven by both global events and regional factors, and in Devonian evolutionary and environmental patterns. These findings enhance understanding of regional and global conodont biodiversity dynamics, highlight regional differences, and underscore the complex biotic responses to Devonian climatic and sea-level changes.