Reconstruction of the pectoral girdle and forelimb musculature of Megaraptora (Dinosauria: Theropoda).

Autor: Aranciaga Rolando AM; Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia,' CONICET, CABA, Argentina., Novas FE; Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia,' CONICET, CABA, Argentina., Calvo JO; Grupo de Transferencia Proyecto Dino, CIGPat, Facultad de Ingeniería, Departamento de Geología y Petróleo, Universidad Nacional del Comahue, Neuquén, Argentina.; Parque Natural Geo-Paleontológico Proyecto Dino, Grupo de Transferencia Proyecto Dino, Facultad de Ingeniería, Universidad Nacional del Comahue, Neuquén, Argentina.; Facultad de Ciencias Exactas y Naturales, Universidad Nacional de la Pampa, Santa Rosa, La Pampa, Argentina., Porfiri JD; Museo de Ciencias Naturales, Universidad Nacional del Comahue, Neuquén, Argentina.; Cátedra de Reptiles Mesozoicos, Facultad de Ingeniería, Universidad Nacional del Comahue, Neuquén, Argentina.; Museo del Desierto Patagónico de Añelo, Municipalidad de Añelo/Universidad Nacional del Comahue, Neuquén, Argentina., Dos Santos DD; Museo de Ciencias Naturales, Universidad Nacional del Comahue, Neuquén, Argentina.; Cátedra de Reptiles Mesozoicos, Facultad de Ingeniería, Universidad Nacional del Comahue, Neuquén, Argentina.; Museo del Desierto Patagónico de Añelo, Municipalidad de Añelo/Universidad Nacional del Comahue, Neuquén, Argentina., Lamanna MC; Section of Vertebrate Paleontology, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA.
Jazyk: angličtina
Zdroj: Anatomical record (Hoboken, N.J. : 2007) [Anat Rec (Hoboken)] 2023 Jul; Vol. 306 (7), pp. 1804-1823. Date of Electronic Publication: 2023 Jan 16.
DOI: 10.1002/ar.25128
Abstrakt: Megaraptora is a group of enigmatic, carnivorous non-avian theropod dinosaurs from the Cretaceous of Asia, Australia, and especially South America. Perhaps the most striking aspect of megaraptoran morphology is the large, robustly constructed forelimb that, in derived members of the clade, terminates in a greatly enlarged manus with hypertrophied, raptorial unguals on the medialmost two digits and a substantially smaller ungual on digit III. The unique forelimb anatomy of megaraptorans was presumably associated with distinctive functional specializations; nevertheless, its paleobiological significance has not been extensively explored. Here we draw from observations of the pectoral girdle and forelimb skeletons of Megaraptora and myological assessments of other archosaurian taxa to provide a comprehensive reconstruction of the musculature of this anatomical region in these singular theropods. Many muscle attachment sites on megaraptoran forelimb bones are remarkably well developed, which in turn suggests that the muscles themselves were functionally significant and important to the paleobiology of these theropods. Furthermore, many of these attachments became increasingly pronounced through megaraptoran evolutionary history, being substantially better developed in derived taxa such as Australovenator wintonensis and especially Megaraptor namunhuaiquii than in early branching forms such as Fukuiraptor kitadaniensis. When considered alongside previous range of motion hypotheses for Australovenator, our results indicate that megaraptorans possessed a morphologically and functionally specialized forelimb that was capable of complex movements. Notable among these were extensive extension and flexion, particularly in the highly derived manus, as well as enhanced humeral protraction, attributes that very probably aided in prey capture.
(© 2023 American Association for Anatomy.)
Databáze: MEDLINE
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