Montsecosuchus (Early Cretaceous atoposaurid) soft tissue preservation + monitor lizard head shape and bite force variation
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Ben Creisler
Jun 15, 2026, 3:05:01 PM (4 days ago) Jun 15
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Ben Creisler
Recent reptile papers:
Oscar Castillo-Visa, Phil R Bell, Àngel Galobart & Albert Sellés (2026)
Soft tissue preservation in the Barremian Montsecosuchus depereti (Neosuchia: Atoposauridae)
Zoological Journal of the Linnean Society 207(2): zlag076
doi: https://doi.org/10.1093/zoolinnean/zlag076
https://doi.org/10.1093/zoolinnean/zlag076
Crocodylomorpha (crocodilians and their extinct relatives) have an extensive fossil record that extends from the Late Triassic to the present day. Nevertheless, fossilized soft tissues (e.g. skin and cartilage) are virtually unknown for most clades, with the exception of the marine thalattosuchians. Here, with the assistance of ultraviolet light, we identify and describe a variety of cartilaginous and non-ossified epidermal tissues in the Early Cretaceous (Barremian) putative atoposaurid Montsecosuchus depereti from Spain, which is among the most complete and oldest preserved skin among Crocodylomorpha, with scale architecture varying along its body. Although broadly similar to the integument of extant representatives, Montsecosuchus lacks the deep caudal ‘fin’ and deeply keeled scales on the limbs characteristic of modern crocodylians. Additional features include possible integumentary sensory organs and evidence of banded coloration along the tail. The restricted presence of possible integumentary sensory organs on scale inclusions on the body periphery suggests that such organs first evolved as small, specialized scales prior to assuming a more widespread distribution on basement scales along the body. Preserved cartilaginous tissues (uncinate processes and cartilaginous ribs) in the thoracic region show adaptations in Montsecosuchus for increased respiratory efficiency. These discoveries help to fill gaps in the evolution of the crocodylomorph integument and respiratory apparatus.
Soft tissue preservation in the Barremian Montsecosuchus depereti (Neosuchia: Atoposauridae)
Zoological Journal of the Linnean Society 207(2): zlag076
doi: https://doi.org/10.1093/zoolinnean/zlag076
https://doi.org/10.1093/zoolinnean/zlag076
Crocodylomorpha (crocodilians and their extinct relatives) have an extensive fossil record that extends from the Late Triassic to the present day. Nevertheless, fossilized soft tissues (e.g. skin and cartilage) are virtually unknown for most clades, with the exception of the marine thalattosuchians. Here, with the assistance of ultraviolet light, we identify and describe a variety of cartilaginous and non-ossified epidermal tissues in the Early Cretaceous (Barremian) putative atoposaurid Montsecosuchus depereti from Spain, which is among the most complete and oldest preserved skin among Crocodylomorpha, with scale architecture varying along its body. Although broadly similar to the integument of extant representatives, Montsecosuchus lacks the deep caudal ‘fin’ and deeply keeled scales on the limbs characteristic of modern crocodylians. Additional features include possible integumentary sensory organs and evidence of banded coloration along the tail. The restricted presence of possible integumentary sensory organs on scale inclusions on the body periphery suggests that such organs first evolved as small, specialized scales prior to assuming a more widespread distribution on basement scales along the body. Preserved cartilaginous tissues (uncinate processes and cartilaginous ribs) in the thoracic region show adaptations in Montsecosuchus for increased respiratory efficiency. These discoveries help to fill gaps in the evolution of the crocodylomorph integument and respiratory apparatus.
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Matthieu E Rouault, Karim Daoues, Marc Jaeger, Olivier Antonini, Christophe Hertzog, Marine Giorgiadis & Anthony Herrel (2026)
Drivers of variation in head shape and bite force in monitor lizards Get access Arrow
Biological Journal of the Linnean Society 148(2): blag036
doi: https://doi.org/10.1093/biolinnean/blag036
https://academic.oup.com/biolinnean/article-abstract/148/2/blag036/8707149
Monitor lizards (Varanidae) comprise 88 species exhibiting morphological and ecological diversity. Because diet and habitat impose functional constraints on cranial morphology and bite force, we investigated their evolutionary relationships using phylogenetically informed comparative methods. Body size strongly influenced cranial morphology, initially masking ecological signals. After correcting for size, clear patterns of size-independent cranial shape variation emerged. Insectivorous, arboreal, and saxicolous species exhibited proportionally more elongated heads, consistent with trade-offs favouring jaw closing speed over force, whereas durophagous species showed taller, more robust heads adapted for forceful biting. Comparative analyses indicated that habitat and diet primarily influence head shape rather than size, with habitat effects driven mainly by terrestrial–arboreal contrasts and dietary effects by divergence between durophagous and insectivorous species. Morphological disparity analyses revealed that habitat use structures head shape diversity once size effects are removed, whereas dietary categories show comparable variation. Varanus komodoensis consistently occupied an isolated position in morphospace. Terrestrial and carnivorous species exhibited higher bite forces than arboreal, saxicolous, and insectivorous species, but differences disappeared after accounting for body size. Lower jaw length was the strongest predictor of bite force. Finally, we estimated bite force in the extinct varanid Megalania (Varanus priscus) and compare it to data for other large predators.
Drivers of variation in head shape and bite force in monitor lizards Get access Arrow
Biological Journal of the Linnean Society 148(2): blag036
doi: https://doi.org/10.1093/biolinnean/blag036
https://academic.oup.com/biolinnean/article-abstract/148/2/blag036/8707149
Monitor lizards (Varanidae) comprise 88 species exhibiting morphological and ecological diversity. Because diet and habitat impose functional constraints on cranial morphology and bite force, we investigated their evolutionary relationships using phylogenetically informed comparative methods. Body size strongly influenced cranial morphology, initially masking ecological signals. After correcting for size, clear patterns of size-independent cranial shape variation emerged. Insectivorous, arboreal, and saxicolous species exhibited proportionally more elongated heads, consistent with trade-offs favouring jaw closing speed over force, whereas durophagous species showed taller, more robust heads adapted for forceful biting. Comparative analyses indicated that habitat and diet primarily influence head shape rather than size, with habitat effects driven mainly by terrestrial–arboreal contrasts and dietary effects by divergence between durophagous and insectivorous species. Morphological disparity analyses revealed that habitat use structures head shape diversity once size effects are removed, whereas dietary categories show comparable variation. Varanus komodoensis consistently occupied an isolated position in morphospace. Terrestrial and carnivorous species exhibited higher bite forces than arboreal, saxicolous, and insectivorous species, but differences disappeared after accounting for body size. Lower jaw length was the strongest predictor of bite force. Finally, we estimated bite force in the extinct varanid Megalania (Varanus priscus) and compare it to data for other large predators.
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