 |
| Simplified reconstruction of the study area with the distribution of different facies and the different assemblages of crabs found in different environments. A-F: different decapod assemblages of the studied area (only Brachyura). A: Belsué Platform beds (Proximal-shallow); B: Arguis platform beds (proximal); C: Coral buldups; D: Pectinid platform beds; E: Bryozoan beds; F: Arguis platform beds (distal) and Belsué platform beds (deep). The geographical subdivisions produced by the different anticlines have been omitted to simplify the scheme. Individually framed taxa have larger distribution areas, marked with a dashed line of the same colour as each box where their record is less fragmentary preservation and scattered remains, and a solid line of the same colour where their record is less fragmentary and continuous. Taxa: 1: Carpiliidae indet. 1; 2: Calappilia sp.; 3: Lophoranina sp.; 4: Notopus sp.; 5: Galenopsis crassifrons; 6: Liopsalis anodon; 7: Carpiliidae indet. 2; 8: Gemmellarocarcinus riglosensis; 9: Daira corallina; 10: Pyreneplax cf. basaensis; 11: Portunus catalaunicus; 12: Montezumella cf. amenosi; 13: Retrocypoda almelai; 14: Retropluma eocenica; 15: Magyarcarcinus yebraensis; 16: Harpactocarcinus punctulatus; 17: Micromaia priabonensis?; 18: Leucosidae indet.; 19: Quasilaeviranina sp.; 20: Hepatiscus sp.; 21: Periacanthus horridus Bittner, 1875 . (A11–13, B20–21, D17, E1–2, F14 and 16 reused from Ferratges, 2017 ; C5 and 9 reused from Ferratges et al., 2020a ). in Ferratges, Zamora, Klompmaker et Aurell, 2024. |
Highlights:
• Diverse Eocene invertebrate fauna assemblage found in the Spanish Pyrenees.
• One of first regional studies on decapod distribution in various environments.
• We quantify diversity and abundance of decapod crustaceans in different facies.
• Faunal changes across stratigraphic sequences controlled by tectonics and sediment input.
Abstract
The south-central margin of the Jaca Basin (South-central Pyrenees, Spain) offers well-exposed outcrops ideal for studying the distribution of decapod crustaceans across a mixed carbonate-siliciclastic depositional system during the middle-late Eocene (Bartonian-Priabonian). This study encompasses an area of 1000 km2, featuring environments from siliciclastic coastal plains and deltaic complexes to shallow carbonate and mixed platforms, including coral reefs, extending to prodelta/outer platform deeper conditions. Detailed sampling in four depositional sequences yielded 372 fossil decapod specimens from various lithofacies across 20 localities.
Our analysis identifies 39 decapod species within 22 families and demonstrates ecological zonation of decapods in shallow to relatively deep environments. Diversity peaks in siliciclastic shallow proximal prodelta areas and carbonate bryozoan meadows. Species distribution between carbonate and siliciclastic facies is similar, though taxonomically distinct. Articulated specimens predominantly occur in shallow proximal and relatively deep distal siliciclastic areas, linked to sudden sediment input and high sedimentation rates. These findings elucidate the spatial and temporal distribution factors of decapod crustaceans during the middle-late Eocene, contributing to the broader understanding of palaeoecological patterns in mixed depositional systems.
Keywords: Crustacea, Taxonomy, Bartonian, Priabonian, Palaeoenvironments, Palaeoecology
Fernando A. Ferratges, Samuel Zamora, Adiël A. Klompmaker and Marcos Aurell. 2024. Decapod Crustacean Diversity through time and space in a middle-upper Eocene carbonate-siliciclastic platform (southern Jaca Basin, Pyrenees, Spain). Palaeogeography, Palaeoclimatology, Palaeoecology. 650; 112373. DOI: doi.org/10.1016/j.palaeo.2024.112373
