Ongoing research into the biostratigraphy of the upper Campanian Dinosaur Park Formation
(DPF) of Alberta has demonstrated that megaherbivorous dinosaur taxa (ankylosaurs …

The evolution of quadrupedality from bipedal ancestors is an exceptionally rare transition in
tetrapod evolution, but it has occurred several times within the herbivorous dinosaur clade …

Background In horned dinosaurs, taxonomy is complicated by the fact that the cranial
ornament that distinguishes species changes with age. Based on this observation, it has …

The extinction of non-avian dinosaurs 65 million years ago is a perpetual topic of
fascination, and lasting debate has focused on whether dinosaur biodiversity was in decline …

Prior studies of Mesozoic biodiversity document a diversity peak for dinosaur species in the
Campanian stage of the Late Cretaceous, yet have failed to provide explicit causal …

ABSTRACT A lower jaw and associated postcranial remains from the Late Cretaceous–early
Paleocene Hornerstown Formation of New Jersey form the basis of a new crocodyliform …

Convergent morphologies are thought to indicate functional similarity, arising because of a
limited number of evolutionary or developmental pathways. Extant taxa displaying …

Background The most primitive ornithischian dinosaurs were small bipeds, but
quadrupedality evolved three times independently in the clade. The transition to …

The centrosaurine ceratopsid taxon Pachyrhinosaurus is the most speciose of
centrosaurines, being represented by at least three species (P. canadensis, P. lakustai, and …

The systematic relationships of basal ornithischian dinosaurs remain contentious, especially
the position of basal neornithischians (ie,'hypsilophodontids'). Prior analyses of basal …