Producción CyT
APA - THE EVOLUTION OF BODY SIZE IN CERATOSAURIA: INSIGHTS OF PHYLOGENETIC COMPARATIVE METHODS
Congreso
Fecha:
2024Editorial y Lugar de Edición:
Asociación Paleontológica ArgentinaResumen *
The body size is usually related with physiology, ecology, and use of resources, thus considerably variation in lineage body size signifies variation in biological and evolution processes. In this sense, Cope´s rule postulate that lineages evolve toward increase body size over the time. Additionally, it was postulated that lineage follows the Cope´s rule when species interaction depend on relative body size difference and when the extinction of top predators induces cyclic evolution toward larger body sizes. Ceratosaurs are theropod dinosaurs represented by two principal groups: Noasauridae and Abelisauridae. These groups were morphological, ecological, and body size diverse. A first approximation to Abelisauridae body length evolution was made, suggesting that Abelisauridae followed the Cope’s rule. However, this approximation lacks of phylogenetic comparative framework and new abelisaurid taxa have been discovered in the last decade. Moreover, a phylogenetic framework which elucidate which factors (ecology, phylogeny, behavior, sexual mechanism, etc.) explain better the differences in body size has not been performed yet in any linage of dinosaurs. Here we used the body length (BL) as a body size proxy, two phylogenetic topologies of Ceratosauria obtained under different methods and employed phylogenetic comparative methods to test the Cope’s rule in the BL evolution by address two principal questions: what factor explain better the difference in ceratosaurian BL and what patters of evolution rates, selection strength and constrains explain the variation of BL within Ceratosauria. The Phylogenetic linear regression models indicate that the ecology factor (type of predation strategy) explained better the differences in Ceratosauria BL no matter what phylogenetic topology and evolution model considered. Moreover, the presence of large-abelisaurids with carcharodontosaurids joined with the possible differences in prey selection, the low levels of disparity over the time and the low evolution rates estimated in the evolutionary modeling, suggest that abelisaurids BL was constrained. The cursorial abilities suggested for abelisaurids joined with the specialized predation strategy might have constrained the increase of larger BL in Late Cretaceous abelisaurids after the extinction of carcharodontosaurids at the end of Turonian times. On the other hand, Noasauridae decrees body size towards phylogeny maybe related to reduction of niche overlapping with abelisaurids. However, the body plan of Noasauridae remains very different of early divergence ceratosaurs and other theropods so that they probably differ in feeding and strategy mechanism. Información suministrada por el agente en SIGEVAPalabras Clave
Copes ruleBody lenghtCeretasoauria