Marine subsidization of Cretaceous dinosaurian ecosystems + dinosaur tracks depositional environments in Upper Jurassic of Algeria + Late Triassic forests in Germany (free pdfs)and
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Ben Creisler
Sep 30, 2026, 2:30:18 PMSep 30
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Ben Creisler
New papers:
Free pdf:
Clayton W. Forster, Celina A. Suarez, Thomas M. Cullen, Lindsay E. Zanno and Ethan G. Hyland (2026)
Marine subsidization of dinosaurian ecosystems
Frontiers in Ecology and Evolution 14: 1895247.
doi: https://doi.org/10.3389/fevo.2026.1895247
https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2026.1895247/full
Marine subsidization (MS) of terrestrial ecosystems, in the form of marine-derived organic matter, energy, and nutrients, is a well-known phenomenon on modern coastlines. However, MS is rarely mentioned or considered in studies of Cretaceous terrestrial coastal ecosystems. Many studies of Cretaceous coastal ecosystems have noted `anomalous' carbon isotope (δ13C) values much higher than anticipated from comparisons of the bioapatite of dinosaurs and other vertebrates and their presumed dietary δ13C value. Since macroalgae and marine plants use a modified C3 photosynthetic pathway resulting in a relatively increased δ13C value, bioapatite of MS consumers will be more enriched in 13C relative to C3 consumers. We used stable carbon isotope analysis of tooth enamel to determine if Cretaceous coastal organisms utilize marine resources by comparing coastal to upland ecosystems. These ecosystems include a variety of vertebrate taxa such as fish, neosuchians (e.g., crocodilians), and dinosaurs. The ecosystem deposits are the following: the Dunvegan Formation of British Columbia and Alberta, Canada; the Wayan Formation and Draney Limestone of Idaho, USA; the Antlers Formation of Oklahoma and Texas, USA; the Woodbine Formation/Group and Lewisville Formation of Texas, USA; and the Mussentuchit Member of the Cedar Mountain Formation, Utah, USA. The δ13C values of coastal assemblages are compared to assemblages of the Cloverly Formation of Wyoming and Montana, USA, an inland intercontinental deposit where MS was expected to be minimal based on known stratigraphic interpretations. We find evidence of MS of coastal ecosystems with relatively high δ13C value of coastal vertebrate enamel (up to >5.5‰ above expected δ13Cenamel values) but not in upland environments. This has implications for back-calculations of dietary plant δ13C value from dinosaur herbivore enamel as previous estimates did not include marine-derived carbon sources in calculations. Therefore, future estimations of Cretaceous vertebrate isotopic offsets must consider the influx of 13C-enriched, marine-derived organic matter and hence, MS of deep-time terrestrial ecosystems. The effects of MS within Cretaceous ecosystems must also be acknowledged as potential major ecosystem and trophic drivers.
Clayton W. Forster, Celina A. Suarez, Thomas M. Cullen, Lindsay E. Zanno and Ethan G. Hyland (2026)
Marine subsidization of dinosaurian ecosystems
Frontiers in Ecology and Evolution 14: 1895247.
doi: https://doi.org/10.3389/fevo.2026.1895247
https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2026.1895247/full
Marine subsidization (MS) of terrestrial ecosystems, in the form of marine-derived organic matter, energy, and nutrients, is a well-known phenomenon on modern coastlines. However, MS is rarely mentioned or considered in studies of Cretaceous terrestrial coastal ecosystems. Many studies of Cretaceous coastal ecosystems have noted `anomalous' carbon isotope (δ13C) values much higher than anticipated from comparisons of the bioapatite of dinosaurs and other vertebrates and their presumed dietary δ13C value. Since macroalgae and marine plants use a modified C3 photosynthetic pathway resulting in a relatively increased δ13C value, bioapatite of MS consumers will be more enriched in 13C relative to C3 consumers. We used stable carbon isotope analysis of tooth enamel to determine if Cretaceous coastal organisms utilize marine resources by comparing coastal to upland ecosystems. These ecosystems include a variety of vertebrate taxa such as fish, neosuchians (e.g., crocodilians), and dinosaurs. The ecosystem deposits are the following: the Dunvegan Formation of British Columbia and Alberta, Canada; the Wayan Formation and Draney Limestone of Idaho, USA; the Antlers Formation of Oklahoma and Texas, USA; the Woodbine Formation/Group and Lewisville Formation of Texas, USA; and the Mussentuchit Member of the Cedar Mountain Formation, Utah, USA. The δ13C values of coastal assemblages are compared to assemblages of the Cloverly Formation of Wyoming and Montana, USA, an inland intercontinental deposit where MS was expected to be minimal based on known stratigraphic interpretations. We find evidence of MS of coastal ecosystems with relatively high δ13C value of coastal vertebrate enamel (up to >5.5‰ above expected δ13Cenamel values) but not in upland environments. This has implications for back-calculations of dietary plant δ13C value from dinosaur herbivore enamel as previous estimates did not include marine-derived carbon sources in calculations. Therefore, future estimations of Cretaceous vertebrate isotopic offsets must consider the influx of 13C-enriched, marine-derived organic matter and hence, MS of deep-time terrestrial ecosystems. The effects of MS within Cretaceous ecosystems must also be acknowledged as potential major ecosystem and trophic drivers.
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Free pdf:
Kacemi Ali, Benhamou Miloud, Boucif Abdelkader, Benramdane Hocine & Hebib Hakim (2026)
Évolution des milieux de dépôt et traces des dinosauriens du Jurassique supérieur dans les Monts des Ksour (Atlas saharien, Algérie)
Evolution of depositional environments and dinosaur tracks of the Upper Jurassic in the Ksour Mountains (Saharan Atlas, Algeria)
Estudios Geológicos 82(2): 1154 (in French)
doi: https://doi.org/10.3989/egeol.45894.1154
https://estudiosgeol.revistas.csic.es/index.php/estudiosgeol/article/view/1154
The Aïssa Formation of Upper Jurassic age crops out on both sides of the North Atlas Fault (NAF) (Souiga-Mélah-Zerga de Sfissifa Ridge). In the eastern sector, within the Atlas trough, it occurs as large anticlines, whereas in the western sector, within the Pre-Atlas trough (Forthassa area), it is exposed in a synclinal structure with much less developed relief. This latter area has yielded remains of the Ksour dinosaur (Chebsaurus), as well as twelve sites with dinosaur and crocodilian trackways that remain unexcavated, while no comparable discoveries have been reported from the Atlas trough. An integrated structural, sedimentological, and paleontological approach applied to these two domains allowed the identification of a SSW-NNE, trending morphostructural axis located southwestern of the North Atlas Accident (Zerga of Sfissifa Mountain), separating the two juxtaposed structural domains. Sedimentary records in the Atlas trough correspond to progradational sequences with SW-NE deltaic dynamics, dominated by delta-front facies. In contrast, in the Pre-Atlas trough, tidal influence is more pronounced, and depositional sequences evolve toward a deltaic floodplain environment, with a stronger development of brackish lagoonal deposits under arid climatic conditions. These paleoenvironmental conditions promoted the proliferation of dinosaurs and crocodilians during the Oxfordian-Kimmeridgian interval.
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Free pdf:
Aowei Xie, Evelyn Kustatscher, Klaus-Martin Moldenhauer & Dieter Uhl (2026)
Fossil wood reveals climate stress and fungal decomposition in Late Triassic (Norian) forests in central Europe
Papers in Palaeontology 12(5): e70129
doi: https://doi.org/10.1002/spp2.70129
https://onlinelibrary.wiley.com/doi/10.1002/spp2.70129
Free pdf:
https://onlinelibrary.wiley.com/doi/epdf/10.1002/spp2.70129
Late Triassic forests in Central Europe developed under a seasonal sub-tropical climate while the supercontinent Pangea was breaking up. Although permineralized fossil wood from this interval is abundant, its palaeoclimatic and palaeoecological significance has so far remained largely unexplored. Here we present a detailed anatomical, taphonomic and dendrochronological study of an Agathoxylon log and associated wood remains collected from the Late Triassic Löwenstein Formation (Norian, Keuper) at the locality Neuenplos in Bavaria, southern Germany. Tree height reconstruction and longevity estimation indicate that the tree reached c. 43 m in height and may have survived for more than 500 years, placing it within an old-growth Keuper forest. More than 20 successive growth rings, including biennial narrow rings, yield a mean sensitivity of 0.67, reflecting inter-annual variability driven by alternating wet–dry seasons typical of a semi-arid sub-tropical setting; false rings record episodic water stress during the growing season. Fungal decay patterns (white rot and brown rot) demonstrate post-mortem saproxylic activity. Together, these data reconstruct a dynamic ecosystem in which large conifer trees endured fluctuating climate stresses while providing substrate for diverse fungal decomposers, thereby shedding light on nutrient cycling processes in Triassic continental forests. Our results provide a robust palaeoclimate archive and highlight the importance of fossil wood in reconstructing ancient forest resilience, with implications for understanding vegetation dynamics under contemporary climate change.
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