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  • A unique predator in a unique ecosystem: modelling the apex predator within a Late Cretaceous crocodyliform‐dominated fauna from Brazil
Title: A unique predator in a unique ecosystem: modelling the apex predator within a Late Cretaceous crocodyliform‐dominated fauna from Brazil
Abstract Theropod dinosaurs were relatively scarce in the Late Cretaceous ecosystems of southeast Brazil. Instead, hypercarnivorous crocodyliforms known as baurusuchids were abundant and probably occupied the ecological role of apex predators. Baurusuchids exhibited a series of morphological adaptations hypothesized to be associated with this ecological role, but quantitative biomechanical analyses of their morphology have so far been lacking. Here, we employ a biomechanical modelling approach, applying finite element analysis (FEA) to models of the skull and mandibles of a baurusuchid specimen. This allows us to characterize the craniomandibular apparatus of baurusuchids, as well as to compare the functional morphology of the group with that of other archosaurian carnivores, such as theropods and crocodylians. Our results support the ecological role of baurusuchids as specialized apex predators in the continental Late Cretaceous ecosystems of South America. With a relatively weak bite force (~600 N), the predation strategies of baurusuchids likely relied on other morphological specializations, such as ziphodont dentition and strong cervical musculature. Comparative assessments of the stress distribution and magnitude of scaled models of other predators (the theropodAllosaurus fragilisand the living crocodylianAlligator mississippiensis) consistently show different responses to loadings under the same functional scenarios, suggesting distinct predatory behaviors for these animals. The unique selective pressures in the arid to semi‐arid Late Cretaceous ecosystems of southeast Brazil, which were dominated by crocodyliforms, possibly drove the emergence and evolution of the biomechanical features seen in baurusuchids, which are distinct from those previously reported for other predatory taxa.  more » « less
Award ID(s):
1754596 1754659
PAR ID:
10451011
Author(s) / Creator(s):
 ;  ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
Journal of Anatomy
Volume:
237
Issue:
2
ISSN:
0021-8782
Page Range / eLocation ID:
p. 323-333
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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