Chemical alteration of Cretaceous crocodyliform fossils + avian wing bone architecture + mammal vocal and brain evolution + Taeniolabis (Paleocene multituberculate) osteology
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Ben Creisler
Oct 15, 2025, 4:57:13 PM (4 days ago) Oct 15
to DinosaurMa...@googlegroups.com
Ben Creisler
Free pdf:
Fabio Alfieri, Oliver E. Demuth, Elizabeth M. Steell, Anne-Claire Fabre & Daniel J. Field (2025)
Constrained variation in the internal architecture of avian wing bones
Functional Ecology (advance online publication)
doi: https://doi.org/10.1111/1365-2435.70178
https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2435.70178
Free pdf:
https://besjournals.onlinelibrary.wiley.com/doi/epdf/10.1111/1365-2435.70178
Plain language summary:
https://fesummaries.wordpress.com/2025/09/19/why-bird-wing-bones-look-so-similar-inside-no-matter-how-they-live/
Extant birds exhibit remarkable ecological disparity accompanied by widespread skeletal convergence driven by functional adaptation. Investigations of morphofunctional associations with ecological factors have frequently focused on the external morphology of avian wing bones; however, the extent to which such associations also apply to the internal structure of the wing skeleton remains understudied.
Here, we investigate the disparity of the internal epiphyseal and diaphyseal structure of the avian humerus and ulna, and explore its correlates with ecology. Our dataset of 140 species spans extant bird diversity.
Internal structure of avian wing bones exhibits limited ecological signal beyond expected secondary trends related to flightlessness and marine habits. Our work instead shows that variation is primarily determined by body size.
Our outcomes suggest that functional constraints on internal wing bone structure imposed by flight are essentially universal across flying birds irrespective of most ecological habits and flight styles. Despite this broad lack of ecological signal, distinctive aspects of forelimb internal structure may facilitate the identification of flightless bird taxa in the fossil record.
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Matías I Muñoz, Myriam Marsot, Jacintha Ellers & Wouter Halfwerk (2025)
Tetrapod vocal evolution reveals faster rates and higher-pitched sounds for mammals
Evolution, qpaf209
doi: https://doi.org/10.1093/evolut/qpaf209
https://academic.oup.com/evolut/advance-article/doi/10.1093/evolut/qpaf209/8281974
Using the voice to produce sound is a widespread form of communication and plays an important role across diverse species and contexts. Variation in the rate and mode of sound production has been extensively studied within orders or classes, but understanding vocal signal evolution ultimately requires comparison across all major lineages involved. Here we used phylogenetic comparative methods to investigate the evolution of dominant frequency and its association with body mass across a balanced set of 873 species of mammals, birds and frogs. Our results show that all vocal systems share the same general feature of the negative allometric relationship between body mass and dominant frequency, but that mammals clearly deviate compared to frogs and birds. We found mammals to vocalize at much higher frequencies and their signals evolved 4- to 6-fold faster compared to other tetrapod clades. Although all three groups strongly rely on vocal communication, our findings show that only mammals have extensively explored the spectral acoustic space. We argue that such high vocal diversity of mammals is made possible by their unique hearing system, and discuss the functional drivers that allowed their shared ancestors to evolve a richer array of frequencies than other tetrapods.
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Recent non-dino papers:
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Fellipe Muniz, Annie Hsiou, Fabio Dias de Andrade, Gabriel Osés, Márcia Rizzutto & Mirian Liza Alves Forancelli Pacheco (2025)
Diagenetic characterization of crocodyliform fossils from the Adamantina Formation (Upper Cretaceous, Bauru Group): evaluating the chemical alteration of skeletal tissues through a multi-technique approach
Cretaceous Research 106248
doi: https://doi.org/10.1016/j.cretres.2025.106248
https://www.sciencedirect.com/science/article/abs/pii/S0195667125001715
Highlights
Diagenetic alteration of fossil crocodyliform skeletal elements is described.
Changes include loss of organics, permineralization, substitutions and recrystallization.
Original bioapatite was transformed into carbonated fluorapatite in all samples.
Alteration degree of fossils and potential to preserve biogenic signals were assessed.
Abstract
The Adamantina Formation hosts one of the most well-documented Late Cretaceous continental faunas in South America, with crocodyliforms standing out for their unusual richness and ecomorphological diversity. While their taxonomy and anatomy have been widely studied, the understanding of their fossilization processes has been largely overlooked. Here, we apply a multi-technique approach to analyze diagenetic alterations of the skeletal elements of crocodyliforms from the Adamantina Formation, combining information from energy dispersive X-ray fluorescence, scanning electron microscopy with energy dispersive X-ray spectroscopy, micro-Raman spectroscopy, and X-ray diffraction. Our results indicate significant structural and compositional changes, including loss of the organic matrix, void permineralization, ionic substitutions, and recrystallization. Although organic molecules were not unambiguously detected, some Raman spectra exhibited bands in the 1000–1800 cm-1 range that resemble signals previously linked to organic compounds, but which may instead result from fluorescence induced by rare earth elements. Void-filling minerals reflect the prevailing influence of both alkaline (e.g., calcite, relict siderite) and oxidizing (iron oxyhydroxides) pore waters. All samples showed transformation of the original bioapatite into carbonated fluorapatite, highlighting the importance of the precipitation of a more thermodynamically stable phase for the long-term survival of skeletal remains. Raman spectroscopy further revealed differences in fossil apatite preservation among samples, with some showing less alteration and potentially storing original chemical information. The combination of techniques used in this study allowed a comprehensive assessment of the mode and degree of diagenetic alteration of crocodyliform remains, which might be useful when selecting samples for molecular or isotopic studies.
Fellipe Muniz, Annie Hsiou, Fabio Dias de Andrade, Gabriel Osés, Márcia Rizzutto & Mirian Liza Alves Forancelli Pacheco (2025)
Diagenetic characterization of crocodyliform fossils from the Adamantina Formation (Upper Cretaceous, Bauru Group): evaluating the chemical alteration of skeletal tissues through a multi-technique approach
Cretaceous Research 106248
doi: https://doi.org/10.1016/j.cretres.2025.106248
https://www.sciencedirect.com/science/article/abs/pii/S0195667125001715
Highlights
Diagenetic alteration of fossil crocodyliform skeletal elements is described.
Changes include loss of organics, permineralization, substitutions and recrystallization.
Original bioapatite was transformed into carbonated fluorapatite in all samples.
Alteration degree of fossils and potential to preserve biogenic signals were assessed.
Abstract
The Adamantina Formation hosts one of the most well-documented Late Cretaceous continental faunas in South America, with crocodyliforms standing out for their unusual richness and ecomorphological diversity. While their taxonomy and anatomy have been widely studied, the understanding of their fossilization processes has been largely overlooked. Here, we apply a multi-technique approach to analyze diagenetic alterations of the skeletal elements of crocodyliforms from the Adamantina Formation, combining information from energy dispersive X-ray fluorescence, scanning electron microscopy with energy dispersive X-ray spectroscopy, micro-Raman spectroscopy, and X-ray diffraction. Our results indicate significant structural and compositional changes, including loss of the organic matrix, void permineralization, ionic substitutions, and recrystallization. Although organic molecules were not unambiguously detected, some Raman spectra exhibited bands in the 1000–1800 cm-1 range that resemble signals previously linked to organic compounds, but which may instead result from fluorescence induced by rare earth elements. Void-filling minerals reflect the prevailing influence of both alkaline (e.g., calcite, relict siderite) and oxidizing (iron oxyhydroxides) pore waters. All samples showed transformation of the original bioapatite into carbonated fluorapatite, highlighting the importance of the precipitation of a more thermodynamically stable phase for the long-term survival of skeletal remains. Raman spectroscopy further revealed differences in fossil apatite preservation among samples, with some showing less alteration and potentially storing original chemical information. The combination of techniques used in this study allowed a comprehensive assessment of the mode and degree of diagenetic alteration of crocodyliform remains, which might be useful when selecting samples for molecular or isotopic studies.
=====
Free pdf:
Fabio Alfieri, Oliver E. Demuth, Elizabeth M. Steell, Anne-Claire Fabre & Daniel J. Field (2025)
Constrained variation in the internal architecture of avian wing bones
Functional Ecology (advance online publication)
doi: https://doi.org/10.1111/1365-2435.70178
https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2435.70178
Free pdf:
https://besjournals.onlinelibrary.wiley.com/doi/epdf/10.1111/1365-2435.70178
Plain language summary:
https://fesummaries.wordpress.com/2025/09/19/why-bird-wing-bones-look-so-similar-inside-no-matter-how-they-live/
Extant birds exhibit remarkable ecological disparity accompanied by widespread skeletal convergence driven by functional adaptation. Investigations of morphofunctional associations with ecological factors have frequently focused on the external morphology of avian wing bones; however, the extent to which such associations also apply to the internal structure of the wing skeleton remains understudied.
Here, we investigate the disparity of the internal epiphyseal and diaphyseal structure of the avian humerus and ulna, and explore its correlates with ecology. Our dataset of 140 species spans extant bird diversity.
Internal structure of avian wing bones exhibits limited ecological signal beyond expected secondary trends related to flightlessness and marine habits. Our work instead shows that variation is primarily determined by body size.
Our outcomes suggest that functional constraints on internal wing bone structure imposed by flight are essentially universal across flying birds irrespective of most ecological habits and flight styles. Despite this broad lack of ecological signal, distinctive aspects of forelimb internal structure may facilitate the identification of flightless bird taxa in the fossil record.
=====
Free pdf:
Matías I Muñoz, Myriam Marsot, Jacintha Ellers & Wouter Halfwerk (2025)
Tetrapod vocal evolution reveals faster rates and higher-pitched sounds for mammals
Evolution, qpaf209
doi: https://doi.org/10.1093/evolut/qpaf209
https://academic.oup.com/evolut/advance-article/doi/10.1093/evolut/qpaf209/8281974
Using the voice to produce sound is a widespread form of communication and plays an important role across diverse species and contexts. Variation in the rate and mode of sound production has been extensively studied within orders or classes, but understanding vocal signal evolution ultimately requires comparison across all major lineages involved. Here we used phylogenetic comparative methods to investigate the evolution of dominant frequency and its association with body mass across a balanced set of 873 species of mammals, birds and frogs. Our results show that all vocal systems share the same general feature of the negative allometric relationship between body mass and dominant frequency, but that mammals clearly deviate compared to frogs and birds. We found mammals to vocalize at much higher frequencies and their signals evolved 4- to 6-fold faster compared to other tetrapod clades. Although all three groups strongly rely on vocal communication, our findings show that only mammals have extensively explored the spectral acoustic space. We argue that such high vocal diversity of mammals is made possible by their unique hearing system, and discuss the functional drivers that allowed their shared ancestors to evolve a richer array of frequencies than other tetrapods.
====
Ornella C. Bertrand & Leah Krubitzer (2025)
The functional adaptations of mammalian brain structures through a behavioural ecology lens
Nature Reviews Biodiversity (advance online publication)
doi: https://doi.org/10.1038/s44358-025-00095-0
https://link.springer.com/article/10.1038/s44358-025-00095-0
The organization of the extant mammalian brain is influenced by development, evolutionary history and the environment. Ecological adaptations specifically have had a major role in shaping the structures and associated functions of the mammalian brain. Although general organization of the brain is relatively conserved in modern mammals, throughout millions of years of evolution mammals have acquired diverse sensory and nervous system adaptations as they invaded new ecological niches. Here, we synthesize palaeontological and neurobiological evidence on mammalian brain structure evolution, the mechanisms behind the observed variation in the size and organization of brain structures, and the effect of behavioural ecology on the evolution of brain functions and associated structures. Neuroecology has advanced greatly over the past 40 years and is now unravelling the complex relationship between specific behaviours and brain organization and function. Relying on different types of data, comparative neurobiologists and palaeontologists strive to answer similar questions about brain evolution, benefiting from a synergistic approach. We conclude this Review by outlining outstanding questions regarding the relationships between structure, function, behaviour and evolution that deserve future research attention, and propose methodologies and approaches to help to resolve these problems.
The functional adaptations of mammalian brain structures through a behavioural ecology lens
Nature Reviews Biodiversity (advance online publication)
doi: https://doi.org/10.1038/s44358-025-00095-0
https://link.springer.com/article/10.1038/s44358-025-00095-0
The organization of the extant mammalian brain is influenced by development, evolutionary history and the environment. Ecological adaptations specifically have had a major role in shaping the structures and associated functions of the mammalian brain. Although general organization of the brain is relatively conserved in modern mammals, throughout millions of years of evolution mammals have acquired diverse sensory and nervous system adaptations as they invaded new ecological niches. Here, we synthesize palaeontological and neurobiological evidence on mammalian brain structure evolution, the mechanisms behind the observed variation in the size and organization of brain structures, and the effect of behavioural ecology on the evolution of brain functions and associated structures. Neuroecology has advanced greatly over the past 40 years and is now unravelling the complex relationship between specific behaviours and brain organization and function. Relying on different types of data, comparative neurobiologists and palaeontologists strive to answer similar questions about brain evolution, benefiting from a synergistic approach. We conclude this Review by outlining outstanding questions regarding the relationships between structure, function, behaviour and evolution that deserve future research attention, and propose methodologies and approaches to help to resolve these problems.
====
Free pdf:
Simone Hoffmann & David W. Krause (2025)
Postcranial osteology and locomotor habits of the North American Paleocene multituberculate Taeniolabis (Taeniolabidoidea, Mammalia)
Palaeobiodiversity and Palaeoenvironments (advance online publication)
doi: https://doi.org/10.1007/s12549-025-00671-4
https://link.springer.com/article/10.1007/s12549-025-00671-4
Postcranial osteology and locomotor habits of the North American Paleocene multituberculate Taeniolabis (Taeniolabidoidea, Mammalia)
Palaeobiodiversity and Palaeoenvironments (advance online publication)
doi: https://doi.org/10.1007/s12549-025-00671-4
https://link.springer.com/article/10.1007/s12549-025-00671-4
Free pdf:
https://www.researchgate.net/publication/396382396_Postcranial_osteology_and_locomotor_habits_of_the_North_American_Paleocene_multituberculate_Taeniolabis_Taeniolabidoidea_Mammalia
Taeniolabis taoensis, the largest known multituberculate, is craniodentally one of the most well-known mammals from the early Paleocene of the Western Interior of the United States of America. Although a few postcranial elements from the Nacimiento Formation of the San Juan Basin, New Mexico, were previously referred to T. taoensis as early as the 1880s, the attribution of most of these specimens to T. taoensis has been questioned. Here we review all of the previously described postcranial remains and confirm that some attributions were indeed incorrect. However, we also place on record several new specimens recently discovered in museum collections that represent the ulna, radius, femur, and calcaneus and that we confidently assign to Taeniolabis based on morphological characters previously identified as unique to multituberculates, large size, and association with craniodental remains of Taeniolabis in the same strata. We compare these elements to those of other multituberculate mammals, particularly to those of other taeniolabidoids. Not unexpectedly considering the heavily constructed, blocky skull of Taeniolabis, all of the postcranial elements are robust, more robust than for any other known multituberculate. Although we are constrained by the poor representation of elements from critical parts of the skeleton and the incomplete nature of the available specimens, we infer that Taeniolabis was a ground-dwelling, quite possibly fossorial mammal.
Taeniolabis taoensis, the largest known multituberculate, is craniodentally one of the most well-known mammals from the early Paleocene of the Western Interior of the United States of America. Although a few postcranial elements from the Nacimiento Formation of the San Juan Basin, New Mexico, were previously referred to T. taoensis as early as the 1880s, the attribution of most of these specimens to T. taoensis has been questioned. Here we review all of the previously described postcranial remains and confirm that some attributions were indeed incorrect. However, we also place on record several new specimens recently discovered in museum collections that represent the ulna, radius, femur, and calcaneus and that we confidently assign to Taeniolabis based on morphological characters previously identified as unique to multituberculates, large size, and association with craniodental remains of Taeniolabis in the same strata. We compare these elements to those of other multituberculate mammals, particularly to those of other taeniolabidoids. Not unexpectedly considering the heavily constructed, blocky skull of Taeniolabis, all of the postcranial elements are robust, more robust than for any other known multituberculate. Although we are constrained by the poor representation of elements from critical parts of the skeleton and the incomplete nature of the available specimens, we infer that Taeniolabis was a ground-dwelling, quite possibly fossorial mammal.
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