Spinosaurinae and Carcharodontosaurinae distribution in middle Cretaceous of Brazil + titanosaur from Lo Hueco with insect bone erosion
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Ben Creisler
Jun 3, 2026, 12:21:03 AM (3 days ago) Jun 3
to DinosaurMa...@googlegroups.com
Ben Creisler
New papers:
Zain Belaústegui, Iván Narváez, Francisco Ortega, Jorge A. Martín-Ávila, Daniel Martín-Vega & Jordi Martinell (2026)
The fossil record of insect bone bioerosion: Insights from titanosaur remains at Lo Hueco (Late Cretaceous, Spain) and implications for continental ichnofacies
Earth-Science Reviews 105561
doi: https://doi.org/10.1016/j.earscirev.2026.105561
https://www.sciencedirect.com/science/article/pii/S0012825226001728
Highlights
Insect bone bioerosion informs in paleoecology, paleoethology and paleoenvironment.
Fossil record of insect bone bioerosion extends from Middle Triassic until today.
Ichnogenus Cubiculum exhibits a diagnostic and unequivocal pouch-shaped morphology.
Dermestid beetles are identified as important modern and fossil bioeroders.
Whole and large skeletons can be used as indicators of the Cubiculum ichnofacies.
Abstract
The fossil record of bone insect bioerosion in continental depositional settings is common and extends from the Middle Triassic until today. Many different examples of bioerosion structures associated with bone tissues of different organisms, from different ages and localities over the world, have been described. Regarding their possible tracemakers, different groups of necrophagous or osteophagous insects have been proposed. Among them, beetles (Coleoptera), particularly members of the family Dermestidae, are frequently proposed, but also termites (Isoptera), mayfly larvae (Asthenopodinae), fleas (Siphonaptera) or bees and wasps (Hymenoptera). The study of this particular fossil record from an ichnologic and taphonomic point of view becomes a very useful tool in order to obtain paleoecological, paleoethological and paleoenvironmental interpretations. Pouch-shaped borings (ascribed to the ichnogenus Cubiculum) found on titanosaurian bone remains from the Upper Cretaceous of Lo Hueco (Cuenca, central Spain) enlarge this bioerosion fossil record and in addition, the first occurrence of this ichnogenus on dinosaur osteoderms is documented. The abundance and exceptional preservation of Cubiculum specimens in Lo Hueco site allow the diagnosis of this ichnogenus to be clarified and emended. Continental Konzentrat-Lagerstätten preserving abundant remains of large vertebrates, such as Lo Hueco, may provide evidence of persistent carcass-supported ecosystems including insect bone bioeroders; for these cases, it is proposed the use of the Cubiculum ichnofacies.
Erick Ribeiro-Souza, Manuel Alfredo Medeiros, Pedro Lucas de Barros Pruciano, Leandro Fernandes Pereira, Lorena Vitória Ferreira Martins, Ana Beatriz Nogueira Aragão & Hannah de Abreu Medeiros (2026)
Spinosaurinae and Carcharodontosaurinae distribution in the middle Cretaceous of the Maranhão state, Brazil
Journal of South American Earth Sciences 106150
doi: https://doi.org/10.1016/j.jsames.2026.106150
https://www.sciencedirect.com/science/article/abs/pii/S0895981126002026
Highlights
Histological data demonstrates significant differences in enamel thickness and dentin growth rates between Spinosaurinae and Carcharodontosaurinae.
Overabundance of theropod (spinosaurid and carcharodontosaurid) dinosaurs extends to northeastern Brazil.
“Middle” Cretaceous of northeastern Brazil had dinosaur communities with at least two different structures.
Late Cretaceous turnover of dinosaur fauna could have initiated before the Turonian.
Abstract
Deposits of middle Cretaceous age from the Itapecuru and Alcântara formations found in the Maranhão state, northeastern Brazil, record a diverse and long lasting paleocommunity. Teeth of the large carcharodontosaurine and spinosaurine theropods are among the most common dinosaur remains recovered from those deposits. Herein, we provide a geographical consolidation of the many occurrences of Spinosaurinae and Carcharodontosaurinae teeth from Maranhão deposits. Additionally, we also provide the first histological descriptions of specimens from this region. Well-preserved specimens of our sample allowed identifications at the subfamily level. The spinosaurine teeth have conidont morphology, prominent and unserrated carinae, lateral faces exhibiting flutes and a nearly straight distal profile. The carcharodontosaurine teeth have ziphodont morphology and distal curvature; carinae with slightly sigmoid aspect exhibiting denticles with strong mesiodistal elongation and separated by wide interdenticular spaces; and braided enamel texture. Histological analysis reveals that carcharodontosaurids possess thinner enamel than spinosaurids. It potentially reflects distinct structural adaptations and mechanical pressures acting on their dentition during prey processing. We discuss evidence from the sauropod and theropod fossil record of Maranhão, studies on tooth growth and replacement rates, and differences in preservation propensity. It remains unclear to what extent tooth frequencies reflect the real structure of dinosaur communities in West Gondwana. If artefact data did not entirely obscure the real structure of the underlying communities, deposits from northeastern Brazil register two different faunal structures in the same geographical and temporal interval. This includes the Early Cretaceous legacy fauna, dominated by spinosaurids and carcharodontosaurids, and the succeeding Late Cretaceous fauna, where abelisaurids emerged as the apex predators. It would be the first record of the dinosaur fauna turnover that occurred during middle Cretaceous, conferring to these deposits a key role in future investigations.
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Spinosaurinae and Carcharodontosaurinae distribution in the middle Cretaceous of the Maranhão state, Brazil
Journal of South American Earth Sciences 106150
doi: https://doi.org/10.1016/j.jsames.2026.106150
https://www.sciencedirect.com/science/article/abs/pii/S0895981126002026
Highlights
Histological data demonstrates significant differences in enamel thickness and dentin growth rates between Spinosaurinae and Carcharodontosaurinae.
Overabundance of theropod (spinosaurid and carcharodontosaurid) dinosaurs extends to northeastern Brazil.
“Middle” Cretaceous of northeastern Brazil had dinosaur communities with at least two different structures.
Late Cretaceous turnover of dinosaur fauna could have initiated before the Turonian.
Abstract
Deposits of middle Cretaceous age from the Itapecuru and Alcântara formations found in the Maranhão state, northeastern Brazil, record a diverse and long lasting paleocommunity. Teeth of the large carcharodontosaurine and spinosaurine theropods are among the most common dinosaur remains recovered from those deposits. Herein, we provide a geographical consolidation of the many occurrences of Spinosaurinae and Carcharodontosaurinae teeth from Maranhão deposits. Additionally, we also provide the first histological descriptions of specimens from this region. Well-preserved specimens of our sample allowed identifications at the subfamily level. The spinosaurine teeth have conidont morphology, prominent and unserrated carinae, lateral faces exhibiting flutes and a nearly straight distal profile. The carcharodontosaurine teeth have ziphodont morphology and distal curvature; carinae with slightly sigmoid aspect exhibiting denticles with strong mesiodistal elongation and separated by wide interdenticular spaces; and braided enamel texture. Histological analysis reveals that carcharodontosaurids possess thinner enamel than spinosaurids. It potentially reflects distinct structural adaptations and mechanical pressures acting on their dentition during prey processing. We discuss evidence from the sauropod and theropod fossil record of Maranhão, studies on tooth growth and replacement rates, and differences in preservation propensity. It remains unclear to what extent tooth frequencies reflect the real structure of dinosaur communities in West Gondwana. If artefact data did not entirely obscure the real structure of the underlying communities, deposits from northeastern Brazil register two different faunal structures in the same geographical and temporal interval. This includes the Early Cretaceous legacy fauna, dominated by spinosaurids and carcharodontosaurids, and the succeeding Late Cretaceous fauna, where abelisaurids emerged as the apex predators. It would be the first record of the dinosaur fauna turnover that occurred during middle Cretaceous, conferring to these deposits a key role in future investigations.
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Free pdf:
Zain Belaústegui, Iván Narváez, Francisco Ortega, Jorge A. Martín-Ávila, Daniel Martín-Vega & Jordi Martinell (2026)
The fossil record of insect bone bioerosion: Insights from titanosaur remains at Lo Hueco (Late Cretaceous, Spain) and implications for continental ichnofacies
Earth-Science Reviews 105561
doi: https://doi.org/10.1016/j.earscirev.2026.105561
https://www.sciencedirect.com/science/article/pii/S0012825226001728
Highlights
Insect bone bioerosion informs in paleoecology, paleoethology and paleoenvironment.
Fossil record of insect bone bioerosion extends from Middle Triassic until today.
Ichnogenus Cubiculum exhibits a diagnostic and unequivocal pouch-shaped morphology.
Dermestid beetles are identified as important modern and fossil bioeroders.
Whole and large skeletons can be used as indicators of the Cubiculum ichnofacies.
Abstract
The fossil record of bone insect bioerosion in continental depositional settings is common and extends from the Middle Triassic until today. Many different examples of bioerosion structures associated with bone tissues of different organisms, from different ages and localities over the world, have been described. Regarding their possible tracemakers, different groups of necrophagous or osteophagous insects have been proposed. Among them, beetles (Coleoptera), particularly members of the family Dermestidae, are frequently proposed, but also termites (Isoptera), mayfly larvae (Asthenopodinae), fleas (Siphonaptera) or bees and wasps (Hymenoptera). The study of this particular fossil record from an ichnologic and taphonomic point of view becomes a very useful tool in order to obtain paleoecological, paleoethological and paleoenvironmental interpretations. Pouch-shaped borings (ascribed to the ichnogenus Cubiculum) found on titanosaurian bone remains from the Upper Cretaceous of Lo Hueco (Cuenca, central Spain) enlarge this bioerosion fossil record and in addition, the first occurrence of this ichnogenus on dinosaur osteoderms is documented. The abundance and exceptional preservation of Cubiculum specimens in Lo Hueco site allow the diagnosis of this ichnogenus to be clarified and emended. Continental Konzentrat-Lagerstätten preserving abundant remains of large vertebrates, such as Lo Hueco, may provide evidence of persistent carcass-supported ecosystems including insect bone bioeroders; for these cases, it is proposed the use of the Cubiculum ichnofacies.
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