Oryctos
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Accès privé :
| volume 3, 2000 |
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Daniel J. Chure, Observation on the morphology and pathology of the gastral basket of Allosaurus, based on a new specimen from Dinosaur National Monument. Oryctos 3, 29-37.
A well preserved and complete gastral basket of Allosaurus (DINO 11541) corrects a number of earlier misinterpretations of this structure in Allosaurus. The basket consists of eighteen rows of gastralia. The first row has only one element per side and these do not overlap medially but rather form a cranially facing notch. All other rows have two elements per side, the medial one being the longer. The right and left medial elements overlap at the midline of the basket. Allosaurus has only four elements per gastral row. Previous interpretations for Allosaurus have been as high as nine elements per row. The supposed fused, V-shaped median gastral element is now known to be a furcula. The supposed four lateral elements in USNM 4734 are actually all part of a single medial element injured during life and healed as a series of pseudoarthroses. The presence of pseudoarthroses and calluses in other medial gastral elements of USNM 4734 further support this interpretation. The presence of similar pathologies in the gastralia of another specimen of Allosaurus (USNM 8367) as well as in the dorsal ribs specimen of Acrocanthosaurus atokensis (SMU 74646) suggests that such injuries were not uncommon in allosauroid theropods. These injuries may be the result of either struggles with prey or intraspecific behavior, such as kicking or head-flank butting. Keywords: Dinosauria, Theropoda, Osteology, Allosaurus, Gastralia, Jurassic, Morrison, Pathology
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