Lentamanusuchus, new hupehsuchian from Lower Triassic of China + desmatosuchin aetosaurs from Triassic of India
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Ben Creisler
Oct 8, 2025, 4:19:26 PM (11 days ago) Oct 8
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Ben Creisler
New papers:
Lentamanusuchus hubeiensis gen. et sp. nov.
Yu Qiao, Masaya Iijima & Jun Liu (2025)
A new hupehsuchian (Reptilia: Ichthyosauromorpha) with widely spaced autopodium from the marine Lower Triassic of South China
Journal of Systematic Palaeontology 23(1): 2560884
doi: https://doi.org/10.1080/14772019.2025.2560884
https://www.tandfonline.com/doi/full/10.1080/14772019.2025.2560884
Hupehsuchia is a group of marine reptiles from the uppermost Lower Triassic of South China, known for their segmented neural spines covered by dermal ossicles and polydactyl forelimbs. Although five genera and species are currently known for this group, our understanding of their true diversity is limited. In this study, we report a new hupehsuchian, Lentamanusuchus hubeiensis gen. et sp. nov., based on the combination of unique characters in the trunk region and forelimb. These include widely spaced autopodial elements, an extra distal carpal and metacarpal, and a two-layered dermal armour. Phylogenetic analysis recovered the new species as a sister taxon to Parahupehsuchinae within Hupehsuchidae, supporting the gradual addition of extra carpal and digital elements in hupehsuchians. The widely spaced autopodia of Lentamanusuchus hubeiensis represent previously unknown morphologies in hupehsuchians. The wide spacing of the proximal autopodia, along with hyperphalangy, may help smooth the paddle surface to reduce vortices during wrist and proximal digit flexion and extension while swimming. Alternatively, it could result from reduced ossification of manual elements due to diminished muscular control in the manus.
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Atrayee Haldar, Sanghamitra Ray & Saswati Bandyopadhyay (2025)
First report of desmatosuchin aetosaurs (Diapsida, Archosauria) from the lower part of Dharmaram Formation and a biostratigraphic re-evaluation of the upper Triassic horizons of India
Historical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2025.2569748
https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2569748
Two desmatosuchin aetosaurs, taxa I–II, based on isolated but distinctive paramedian osteoderms, are reported from the lower Dharmaram Formation of India. These are morphologically differentiated based on shape proportions, dorsal ornamentation, nature of anterior bar and dorsal eminence, and tongue-in-groove articulation on both medial and lateral edges (taxon I). Comparison with other aetosaurian osteoderms revealed that taxon I is the first record of Desmatosuchus from India. Taxon II closely resembles Desmatosuchus smalli, and is also assigned to Desmatosuchini. Recognition of these taxa represents the first Indian record of Desmatosuchini and augmented the diversity of endemic desmatosuchins in India as well as in Gondwana. Quantitative analyses corroborate the interrelationships of the major clades of Aetosauria and elucidate the significance of the osteoderm characters. A re-evaluation of the lowest and highest occurrences of Late Triassic tetrapod assemblages from India has led to the identification of Assemblage Eubiozones. The work highlights several new biostratigraphic insights including the absence of synchronicity between faunal and lithological boundaries, absence of diagnostic Rhaetian index fossils, considerable overlap of temporal ranges, and the absence of appreciable biochronological separation resulting in the assignment of a single Upper Maleri-Lower Dharmaram Assemblage Eubiozone of mid-to-late Norian age.
LSIDurn:lsid:zoobank.org:pub:6BC1AB57-9B2D-487E-B579-AAC1ED0D2827
====
Lentamanusuchus hubeiensis gen. et sp. nov.
Yu Qiao, Masaya Iijima & Jun Liu (2025)
A new hupehsuchian (Reptilia: Ichthyosauromorpha) with widely spaced autopodium from the marine Lower Triassic of South China
Journal of Systematic Palaeontology 23(1): 2560884
doi: https://doi.org/10.1080/14772019.2025.2560884
https://www.tandfonline.com/doi/full/10.1080/14772019.2025.2560884
Hupehsuchia is a group of marine reptiles from the uppermost Lower Triassic of South China, known for their segmented neural spines covered by dermal ossicles and polydactyl forelimbs. Although five genera and species are currently known for this group, our understanding of their true diversity is limited. In this study, we report a new hupehsuchian, Lentamanusuchus hubeiensis gen. et sp. nov., based on the combination of unique characters in the trunk region and forelimb. These include widely spaced autopodial elements, an extra distal carpal and metacarpal, and a two-layered dermal armour. Phylogenetic analysis recovered the new species as a sister taxon to Parahupehsuchinae within Hupehsuchidae, supporting the gradual addition of extra carpal and digital elements in hupehsuchians. The widely spaced autopodia of Lentamanusuchus hubeiensis represent previously unknown morphologies in hupehsuchians. The wide spacing of the proximal autopodia, along with hyperphalangy, may help smooth the paddle surface to reduce vortices during wrist and proximal digit flexion and extension while swimming. Alternatively, it could result from reduced ossification of manual elements due to diminished muscular control in the manus.
====
Atrayee Haldar, Sanghamitra Ray & Saswati Bandyopadhyay (2025)
First report of desmatosuchin aetosaurs (Diapsida, Archosauria) from the lower part of Dharmaram Formation and a biostratigraphic re-evaluation of the upper Triassic horizons of India
Historical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2025.2569748
https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2569748
Two desmatosuchin aetosaurs, taxa I–II, based on isolated but distinctive paramedian osteoderms, are reported from the lower Dharmaram Formation of India. These are morphologically differentiated based on shape proportions, dorsal ornamentation, nature of anterior bar and dorsal eminence, and tongue-in-groove articulation on both medial and lateral edges (taxon I). Comparison with other aetosaurian osteoderms revealed that taxon I is the first record of Desmatosuchus from India. Taxon II closely resembles Desmatosuchus smalli, and is also assigned to Desmatosuchini. Recognition of these taxa represents the first Indian record of Desmatosuchini and augmented the diversity of endemic desmatosuchins in India as well as in Gondwana. Quantitative analyses corroborate the interrelationships of the major clades of Aetosauria and elucidate the significance of the osteoderm characters. A re-evaluation of the lowest and highest occurrences of Late Triassic tetrapod assemblages from India has led to the identification of Assemblage Eubiozones. The work highlights several new biostratigraphic insights including the absence of synchronicity between faunal and lithological boundaries, absence of diagnostic Rhaetian index fossils, considerable overlap of temporal ranges, and the absence of appreciable biochronological separation resulting in the assignment of a single Upper Maleri-Lower Dharmaram Assemblage Eubiozone of mid-to-late Norian age.
LSIDurn:lsid:zoobank.org:pub:6BC1AB57-9B2D-487E-B579-AAC1ED0D2827
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