Triassic reptiles from Germany, including Calamosuchus, new phytosaur + plesiosaur taxic diversity sampling (free pdfs)
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Ben Creisler
Dec 4, 2025, 1:15:35 PM (3 days ago) Dec 4
to DinosaurMa...@googlegroups.com
Ben Creisler
Hans-Dieter Sues & Rainer R. Schoch (2025)
Synopsis of the Triassic reptiles from Germany.
Fossil Record 28(2): 411-483.
doi: https://doi.org/10.3897/fr.28.164405
https://fr.pensoft.net/articles.php?id=164405
Triassic strata in the portion of the Central European Basin (CEB) that cover parts of conterminous Germany have yielded a long if discontinuous record of continental tetrapods spanning this period. The classic Germanic Triassic succession comprises two mostly terrestrial units, the Buntsandstein and Keuper groups, separated by the predominantly marine Muschelkalk Group (Fig. 1). Thus, it is not possible to trace lineages of terrestrial tetrapods continuously through the entire Triassic Period. Skeletal remains of Early and early Middle Triassic (Induan-early Anisian) reptiles are rare in the Buntsandstein Group and mainly known from the Upper Buntsandstein Subgroup. The Middle Triassic (Anisian-Ladinian) marine carbonates of the Muschelkalk Group have yielded a considerable diversity of sauropterygians together with a few ichthyopterygians, a possible thalattosaurian, and the long-necked tanysaurian archosauromorph Tanystropheus. The late Middle and Late Triassic continental deposits of the Keuper Group preserve a substantial record of the rapidly diversifying crocodile-line and bird-line archosaurs together with stem-forms of some tetrapod crown clades such as turtles and lepidosaurs. In recent years, many new discoveries have greatly increased our knowledge of reptiles from the Keuper Group, especially from the Ladinian-age Lower Keuper Subgroup. The latest Triassic (Rhaetian) is represented by bonebeds containing bones and teeth of marine and continental vertebrates including reptiles that were deposited before the Early Jurassic transgression completely inundated the CEB.
This paper provides a detailed overview of the currently known taxa of reptiles from the Triassic of conterminous Germany and explores some more general aspects of this fossil record.
====
Franco Roger Aspromonte & José Patricio O'Gormán (2025)
Assessing the effect of sampling proxies on plesiosaur taxic diversity with comments on implications for Mesozoic sampling design.
Fossil Record 28(2): 397-410.
doi: https://doi.org/10.3897/fr.28.e173497
https://fr.pensoft.net/article/173497/
The fossil record of plesiosaurs, while extensive, is strongly affected by geological and anthropogenic biases that may obscure true diversity patterns. This study evaluates the influence of rock availability and sampling effort on taxic diversity estimates (TDE) of plesiosaurians throughout the Mesozoic period and proposes a method for determining priority stages for future fossil sampling. Two primary proxies—the number of fossiliferous marine formations (FMF) and fossil marine collections (FMC)—are considered. Our findings indicate that neither FMF nor FMC alone accounts for observed diversity peaks and troughs in plesiosaurian TDE. To address this, we integrate phylogenetic diversity estimates (PDE) into our framework, using the difference between PDE and TDE (i.e., phylogenetic residuals) to identify stratigraphic stages where recorded diversity likely underrepresents true lineage richness. This combined approach reveals that some previously recognized declines in TDE—such as during the Berriasian—are consistent with low sampling proxy values and may reflect genuine sampling bias. In contrast, other intervals, particularly the Aalenian–Bathonian, Valanginian and Coniacian ages, exhibit low TDE despite limited rock and collection data but high phylogenetic residuals, highlighting them as high-priority targets for future paleontological fieldwork. These stages represent critical intervals for testing the consistency between diversity models based on sampling proxies and phylogenetically inferred diversity trends.
New papers:
Free pdf:
Calamosuchus gen. nov.
Calamosuchus arenaceus (E. Fraas, 1896) comb. nov. Holotype. SMNS 80737
Calamosuchus arenaceus (E. Fraas, 1896) comb. nov. Holotype. SMNS 80737
Hans-Dieter Sues & Rainer R. Schoch (2025)
Synopsis of the Triassic reptiles from Germany.
Fossil Record 28(2): 411-483.
doi: https://doi.org/10.3897/fr.28.164405
https://fr.pensoft.net/articles.php?id=164405
Triassic strata in the portion of the Central European Basin (CEB) that cover parts of conterminous Germany have yielded a long if discontinuous record of continental tetrapods spanning this period. The classic Germanic Triassic succession comprises two mostly terrestrial units, the Buntsandstein and Keuper groups, separated by the predominantly marine Muschelkalk Group (Fig. 1). Thus, it is not possible to trace lineages of terrestrial tetrapods continuously through the entire Triassic Period. Skeletal remains of Early and early Middle Triassic (Induan-early Anisian) reptiles are rare in the Buntsandstein Group and mainly known from the Upper Buntsandstein Subgroup. The Middle Triassic (Anisian-Ladinian) marine carbonates of the Muschelkalk Group have yielded a considerable diversity of sauropterygians together with a few ichthyopterygians, a possible thalattosaurian, and the long-necked tanysaurian archosauromorph Tanystropheus. The late Middle and Late Triassic continental deposits of the Keuper Group preserve a substantial record of the rapidly diversifying crocodile-line and bird-line archosaurs together with stem-forms of some tetrapod crown clades such as turtles and lepidosaurs. In recent years, many new discoveries have greatly increased our knowledge of reptiles from the Keuper Group, especially from the Ladinian-age Lower Keuper Subgroup. The latest Triassic (Rhaetian) is represented by bonebeds containing bones and teeth of marine and continental vertebrates including reptiles that were deposited before the Early Jurassic transgression completely inundated the CEB.
This paper provides a detailed overview of the currently known taxa of reptiles from the Triassic of conterminous Germany and explores some more general aspects of this fossil record.
====
Free pdf:
Franco Roger Aspromonte & José Patricio O'Gormán (2025)
Assessing the effect of sampling proxies on plesiosaur taxic diversity with comments on implications for Mesozoic sampling design.
Fossil Record 28(2): 397-410.
doi: https://doi.org/10.3897/fr.28.e173497
https://fr.pensoft.net/article/173497/
The fossil record of plesiosaurs, while extensive, is strongly affected by geological and anthropogenic biases that may obscure true diversity patterns. This study evaluates the influence of rock availability and sampling effort on taxic diversity estimates (TDE) of plesiosaurians throughout the Mesozoic period and proposes a method for determining priority stages for future fossil sampling. Two primary proxies—the number of fossiliferous marine formations (FMF) and fossil marine collections (FMC)—are considered. Our findings indicate that neither FMF nor FMC alone accounts for observed diversity peaks and troughs in plesiosaurian TDE. To address this, we integrate phylogenetic diversity estimates (PDE) into our framework, using the difference between PDE and TDE (i.e., phylogenetic residuals) to identify stratigraphic stages where recorded diversity likely underrepresents true lineage richness. This combined approach reveals that some previously recognized declines in TDE—such as during the Berriasian—are consistent with low sampling proxy values and may reflect genuine sampling bias. In contrast, other intervals, particularly the Aalenian–Bathonian, Valanginian and Coniacian ages, exhibit low TDE despite limited rock and collection data but high phylogenetic residuals, highlighting them as high-priority targets for future paleontological fieldwork. These stages represent critical intervals for testing the consistency between diversity models based on sampling proxies and phylogenetically inferred diversity trends.
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