Large theropod dinosaur footprint associations in western Gondwana: Behavioural and palaeogeographic implications

In modern terrestrial ecosystems, the population size of large predators is low, and a similar pattern has usually been assumed for dinosaurs. However, fossil finds of monospecific, large theropod accumulations suggest that population dynamics were more complex. Here, we report two Early Cretaceous...

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Detalhes bibliográficos
Autores: Moreno, Karen, de Valais, Silvina, Blanco, Nicolás, Tomlinson, Andrew J., Jacay, Javier, Calvo, Jorge O.
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2012
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositório:CONICET Digital (CONICET)
Idioma:inglês
OAI Identifier:oai:ri.conicet.gov.ar:11336/195158
Acesso em linha:http://hdl.handle.net/11336/195158
Access Level:Acceso aberto
Palavra-chave:BEHAVIOUR
CHILE
EARLY CRETACEOUS
FOOTPRINTS
GONDWANA
PALAEOGEOGRAPHY
PERU
THEROPODA
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Descrição
Resumo:In modern terrestrial ecosystems, the population size of large predators is low, and a similar pattern has usually been assumed for dinosaurs. However, fossil finds of monospecific, large theropod accumulations suggest that population dynamics were more complex. Here, we report two Early Cretaceous tracksites dominated by large theropod footprints, in Querulpa Chico (Peru) and Chacarilla (Chile). The two sites correspond to distinct depositional environmentstidal basin/delta (Querulpa Chico) and meandering river (Chacarilla)-with both subject to extensive arid or semiarid palaeoclimatic conditions. Although most trackways show no preferred orientation, a clear relationship between two trackmakers is observed in one instance. This observation, coupled with the high abundance of trackways belonging to distinct large theropods, and the exclusion of tracks of other animals, suggests some degree of grouping behaviour. The presence of freshwater sources in a dry climate and perhaps social behaviour such as pair bonding may have promoted interactions between large carnivores. Further, the occurrence of these two tracksites confirms that large theropod dinosaurs, possibly spinosaurids and/or carcharodontosaurids, existed on the western margin of Gondwana as early as the earliest Cretaceous.