Ecological restructuring of North Tethyan marine vertebrate communities triggered by the end-Cretaceous extinction

Proceedings of the National Academy of Sciences, Journal Year: 2025, Volume and Issue: 122(22)

Published: May 19, 2025

The ecological upheavals produced by the Cretaceous–Paleogene mass extinction event (K-Pg, −66 Ma) have been mostly studied at large scale with emphasis on clades’ diversity dynamics. How this affected structure of paleocommunities is comparatively less investigated, especially within vertebrate clades like fish. Here, we quantified changes in contribution elasmobranchs (sharks, skates, rays) and actinopterygians (ray-finned fishes) to fish community across K-Pg analyzing ichthyolith (fossil teeth denticles) abundance through time. Based extensive sampling 20 horizons from two outcrops spanning Austria (>4 tons rock, >9,000 ichthyoliths), show that fostered elasmobranch while reducing actinopterygian density Tethys Ocean. Elasmobranch dominance postextinction communities not driven estimated local environmental change (paleobathymetry, bottom-water oxygenation) may relate greater independence clade lower trophic levels their ecology early life stages than actinopterygians. We further measured size assemblages found initiated an increase range niche space occupied simultaneously demise communities. Finally, using fine taxonomic resolution fossil record, demonstrate fluctuations controlled richness, which are decoupled global-scale upheavals. Our results challenge previous hypotheses provide insights into global regional forcing over a event.

Language: Английский

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A new deep-marine elasmobranch fauna from the Late Cretaceous of Bergen (Bavaria, Germany) dominated by squaliform sharks

PalZ, Journal Year: 2025, Volume and Issue: unknown

Published: April 1, 2025

Language: Английский

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Elasmobranch assemblages from a bathyal environment spanning the Cretaceous-Paleogene boundary in Austria

Mitteilungen der Österreichischen Geologischen Gesellschaft/Austrian journal of earth sciences, Journal Year: 2024, Volume and Issue: 117(1), P. 1 - 11

Published: Jan. 1, 2024

Abstract Extensive bulk-sampling of the continuous Cretaceous-Paleogene boundary section at Gams (Styria, Austria) allows for first time description elasmobranch communities inhabiting bathyal environment this well-known section. The sampled succession comprises six horizons from uppermost Maastrichtian (upper part Nephrolites frequens Zone CC26) and five lowermost Danian (Zone NP1), which yielded a total 1852 teeth. Although majority teeth are not well preserved, study enabled least 16 taxa orders Hexanchiformes, Squaliformes, Orectolobiformes, Lamniformes Carcharhiniformes, providing rare snapshot diversity specific environmental setting. Beside minor fluctuations between assemblages, extensive did reveal marked decline related to end-Cretaceous mass extinction event. However, noteworthy correlation deepening upward trend with appearance frilled goblin sharks points changes in palaeobathymetry, is also reflected increase proportion squaliform horizon. Furthermore, extinct triakid Palaeogaleus were recovered exclusively deeper deposits, expanding palaeoecological range genus down fairly deep marine environments. In addition, provides record lamniform Cretolamna ex gr. borealis Tethyan Realm palaeogeographic distribution group.

Language: Английский

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A New Genus of Kitefin Sharks (Squaliformes, Dalatiidae) from the Berezovaya Strata (Lower Paleocene) of the Lower Volga Region

Paleontological Journal, Journal Year: 2024, Volume and Issue: 58(5), P. 556 - 566

Published: Oct. 1, 2024

Language: Английский

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