Gigantic dermochelyid turtle from Upper Cretaceous of Egypt + Diadectes juvenile with bite marks (Permian, Texas)
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Ben Creisler
Feb 26, 2026, 3:19:59 PM (12 days ago) Feb 26
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Ben Creisler
Recent papers:
Trophic interactions between large predators and herbivores are unknown in the fossil record of Permo-Carboniferous tetrapods at a time when these members of the terrestrial vertebrate communities make their first appearance and undergo initial diversification in an increasingly complex community. Here we report on the presence of numerous tooth markings on three juvenile skeletons of the herbivore Diadectes from the early Permian of Texas. As the first terrestrial vertebrate herbivores, diadectids occupied a crucial eco-morphological space of the terrestrial community, as primary consumers that were able to orally process and consume high-fiber plants, a previously unexplored resource. The tooth marks indicate that the feeding behaviour included both muscle de-fleshing and scavenging on cartilage-rich joint areas in the appendicular skeletons. Anatomy of the tooth marks indicate that various predators could have produced the tooth marks, such as the apex predators Varanops and Dimetrodon, as well as the trematopid amphibian Acheloma. In addition, boring marks are also present and likely produced by arthropod larvae. Although these skeletons may have been produced by active predation, their subsequent accumulation in a probable flooding event and extensive exposure before burial, does not allow us to differentiate active predation and scavenging. Nevertheless, this discovery represents the earliest direct evidence of predator-prey trophic interactions among large-bodied terrestrial vertebrates during the initial stages of amniote evolution.
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Mohamed K. Mousa, Abdel Aziz A. Tantawy & Gebely A. Abu El-Kheir (2026)
First known gigantic dermochelyid turtle (Pan-Chelonioidea) from the Upper Cretaceous deposits of Dakhla Oasis, Western Desert, Egypt.
Cretaceous Research 106357
doi: https://doi.org/10.1016/j.cretres.2026.106357
https://www.sciencedirect.com/science/article/abs/pii/S0195667126000467
Fossil remains of the pelvic girdle of a dermochelyid turtle were recovered from the Beris Member (Maastrichtian) of the Dakhla Formation, Dakhla Oasis, Western Desert of Egypt. The discovered specimen including both ilia, ischia and pubes exhibits characteristic features of Pan-Chelonioidea such as the expanded pubic lateral and medial processes and a robust illium. It is characterized by a distinct subdivided thyroid fenestra. This finding represents the detailed description of the first gigantic dermochelyid pelvic girdle elements from Maastrichtian deposits in Africa. The discovering of the dermochelyid materials in the Western Desert of Egypt provides further insights of the paleobiogeographic distribution of dermochelyid turtles in the Upper Cretaceous of North Africa. This discovery increases the paleontological significance of the Upper Cretaceous deposits of Dakhla Oasis.
First known gigantic dermochelyid turtle (Pan-Chelonioidea) from the Upper Cretaceous deposits of Dakhla Oasis, Western Desert, Egypt.
Cretaceous Research 106357
doi: https://doi.org/10.1016/j.cretres.2026.106357
https://www.sciencedirect.com/science/article/abs/pii/S0195667126000467
Fossil remains of the pelvic girdle of a dermochelyid turtle were recovered from the Beris Member (Maastrichtian) of the Dakhla Formation, Dakhla Oasis, Western Desert of Egypt. The discovered specimen including both ilia, ischia and pubes exhibits characteristic features of Pan-Chelonioidea such as the expanded pubic lateral and medial processes and a robust illium. It is characterized by a distinct subdivided thyroid fenestra. This finding represents the detailed description of the first gigantic dermochelyid pelvic girdle elements from Maastrichtian deposits in Africa. The discovering of the dermochelyid materials in the Western Desert of Egypt provides further insights of the paleobiogeographic distribution of dermochelyid turtles in the Upper Cretaceous of North Africa. This discovery increases the paleontological significance of the Upper Cretaceous deposits of Dakhla Oasis.
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Free pdf:
Jordan M. Young, Tea Maho & Robert R. Reisz (2026)
Earliest direct evidence of trophic interactions between terrestrial apex predators and large herbivores
Scientific Reports 16: 6977
doi: https://doi.org/10.1038/s41598-026-38183-6
https://www.nature.com/articles/s41598-026-38183-6
Jordan M. Young, Tea Maho & Robert R. Reisz (2026)
Earliest direct evidence of trophic interactions between terrestrial apex predators and large herbivores
Scientific Reports 16: 6977
doi: https://doi.org/10.1038/s41598-026-38183-6
https://www.nature.com/articles/s41598-026-38183-6
Trophic interactions between large predators and herbivores are unknown in the fossil record of Permo-Carboniferous tetrapods at a time when these members of the terrestrial vertebrate communities make their first appearance and undergo initial diversification in an increasingly complex community. Here we report on the presence of numerous tooth markings on three juvenile skeletons of the herbivore Diadectes from the early Permian of Texas. As the first terrestrial vertebrate herbivores, diadectids occupied a crucial eco-morphological space of the terrestrial community, as primary consumers that were able to orally process and consume high-fiber plants, a previously unexplored resource. The tooth marks indicate that the feeding behaviour included both muscle de-fleshing and scavenging on cartilage-rich joint areas in the appendicular skeletons. Anatomy of the tooth marks indicate that various predators could have produced the tooth marks, such as the apex predators Varanops and Dimetrodon, as well as the trematopid amphibian Acheloma. In addition, boring marks are also present and likely produced by arthropod larvae. Although these skeletons may have been produced by active predation, their subsequent accumulation in a probable flooding event and extensive exposure before burial, does not allow us to differentiate active predation and scavenging. Nevertheless, this discovery represents the earliest direct evidence of predator-prey trophic interactions among large-bodied terrestrial vertebrates during the initial stages of amniote evolution.
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