Comparação funcional dos membros anteriores dos dinossauros saurópodes <i>Lourinhasaurus</i> e <i>Camarasaurus</i> na XXIV EJIP

PT: A XXIV edição do EJIP, em Bogarra, contou com a participação de membros da Faculdade de Ciências da Universidade de Lisboa (FCUL), como é exemplo a apresentação por poster “Show me your moves! A functional comparison of the forelimbs of Lourinhasaurus and Camarasaurus using an open-source musculoskeletal workflow”, por Alexandre Fonseca. Este trabalho explora a morfologia functional do membro anterior de um distintivo camarassáurio de Portugal, comparando-o com Camarasaurus grandis através de técnicas de paleontologia virtual. Entre os resultados estão patentes diferenças fucnionais importantes entre os membros anteriores de ambos os taxa. Esta apresentação por poster foi distinguida com o prémio de “Mejor comunicación en formato póster”.

SP: La XXIV edición del EJIP, celebrada en Bogarra, contó con la participación de miembros de la Facultad de Ciencias de la Universidad de Lisboa (FCUL), como por ejemplo la presentación en póster «Show me your moves! A functional comparison of the forelimbs of Lourinhasaurus and Camarasaurus using an open-source musculoskeletal workflow», a cargo de Alexandre Fonseca. Este trabajo explora la morfología funcional de las extremidades delanteras de un camarasaurio característico de Portugal, comparándolo con Camarasaurus grandis mediante técnicas de paleontología virtual. Entre los resultados se observan importantes diferencias funcionales entre las extremidades delanteras de ambos taxones. Esta presentación en formato póster fue galardonada con el premio a la «Mejor comunicación en formato póster».

Lourinhasaurus alenquerensis is a Portuguese species of camarasaurid sauropod distinguished from Camarasaurus by several osteological features, some of them found in the appendicular skeleton. Hitherto, the functional implications of the camarasaurid forelimb have not been experimentally assessed. Here, we present a digital framework to address this. Within a 3D environment (Blender; version 4.2.0), a musculoskeletal rig was built to test how reconstructed soft tissues (in this case, musculature) constrain the movement of the forelimb of two camarasaurid species, Lourinhasaurus alenquerensis and Camarasaurus grandis. The rigs were animated to simulate various forelimb movements. Then, a Python (version 3.12.10) script was developed to automate the analysis. For each frame of animation, the script calculates the strain ratio of each reconstructed muscle, and outputs it. This method enabled the identification of muscle tension limit, therefore informing about overall ranges of motion. The results obtained through these analyses provide evidence supporting greater ranges of motion in the forelimb of Lourinhasaurus alenquerensis than in the forelimb of Camarasaurus grandis, mainly due to the wider glenoid articulation and lower torsion of the humeral shaft in Lourinhasaurus compared to Camarasaurus grandis. These novelties, together with the previously known distinctions between the appendicular skeletons of Lourinhasaurus alenquerensis and the genus Camarasaurus (such as the proportionally longer forelimb), support the hypothesis that Lourinhasaurus alenquerensis was a camarasaurid with unique locomotor adaptations within the clade. Finally, the developed workflow within Blender and Python script provides researchers, for the first time, a potential open-source option for running musculoskeletal analyses. Further development of this methodology into a Blender add-on will allow free use of these tools in the future.

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Referencia: Fonseca, A., Vidal, D., Ortega, F., Mocho, P. (2026) Show me your moves! A functional comparison of the forelimbs of Lourinhasaurus and Camarasaurus using an open-source musculoskeletal workflow. Libro de resúmenes del XXIV Encuentro de Jóvenes Investigadores en Paleontología (EJIP), Bogarra, Albacete.