INVESTIGADORES
FERNANDEZ Marta Susana
congresos y reuniones científicas
Título:
PHYLOGENETIC PATTERNS, HOMOPLASY, AND THE EVOLUTION OF THE ANTORBITAL FENESTRA IN CROCODYLIFORMES
Autor/es:
LEARDI, J.M.; POL, D.; FERNÁNDEZ, M. S.
Reunión:
Encuentro; 71st Annual Meeting Society of Vertebrate Paleontology; 2011
Resumen:
Crocodyliformes are the only group of Archosauriformes that have enclosed
the antorbital fenestra and internalized the associated pneumatic cavity
multiple times in their evolutionary history. A large-scale phylogenetic
analysis of Crocodyliformes allows evaluating the pattern of character
evolution of this fenestra in the history of the group. The closure of the
antorbital fenestra is optimized as a highly homoplastic process, inferred to
occur independently up to eight times. Although this closure is observed in few
basal crocodyliforms (e.g., Edentosuchus, the Fruita Form), most
transformations are focused in certain mesoeucrocodylian clades. In
notosuchians, a closed antorbital fenestra is observed in derived notosuchians
(including sebecosuchians). However, the presence of an antorbital fenestra in Notosuchus
creates an ambiguous optimization for this character. Furthermore, the
presence of a small fenestra in some Cenozoic sebecosuchians (Bergisuchus and
Iberosuchus) implies a reopening of the fenestra in the evolution of
this group. Among neosuchians, two independent events and Atoposauridae, as
both have small antorbital fenestra. Given that the homology of the antorbital
fenestra of Metriorhynchidae has been recently questioned, an internalized
antorbital fenestra could represent an ambiguous synapomorphy of the
longirostrine clade The evidence at hand indicates the antobital fenestra of
Crocodyliformes is one of the most homoplastic analyzed characters of the
group, suggesting not only the closure of this opening in multiple groups but
also the independent reappearance of a fenestra (that would not be homologous
from a phylogenetic point of view) in some notosuchians and, possibly, in basal
thalattosuchians.and Atoposauridae, as both have small antorbital fenestra.
Given that the homology of the antorbital fenestra of Metriorhynchidae has been
recently questioned, an internalized antorbital fenestra could represent an
ambiguous synapomorphy of the longirostrine clade The evidence at hand indicates the antobital
fenestra of Crocodyliformes is one of the most homoplastic analyzed characters
of the group, suggesting not only the closure of this opening in multiple
groups but also the independent reappearance of a fenestra (that would not be homologous
from a phylogenetic point of view) in some notosuchians and, possibly, in basal
thalattosuchians