The lack of correlation between skull and glottic indices does not support skull morphology as predictor of glottic morphology.
A study published in 2008 by Casey Holliday and Lawrence Witmer found that ornithopods like Edmontosaurus lacked the types of skull joints seen in those modern animals that are known to have kinetic skulls (skulls that permit motion between their constituent bones), such as squamates and birds.
Finding, largely due to a lack of good Albertosaurus skull material, no significant differences to separate the two taxa, Dale Russell declared the name Gorgosaurus a junior synonym of Albertosaurus, which had been named first, and G. libratus was renamed Albertosaurus libratus in 1970.
Whereas their data indicated no difference in helmet use between younger and older injured operators, we found older patients significantly less likely to use a helmet, with lack of helmeting linked to skull fracture and death.
The classic view [ 9, 10] places turtles as the sister group to all other reptiles, mostly on the basis of the lack of temporal fenestration in the skull, a character considered as being ancestral for Reptilia.
Nevertheless, Schurr warns that the lack of large numbers of Paleoamerican skulls makes progress difficult and that the small sample sizes may not show the true morphological and genetic diversity of early American populations.
Due to a lack of specialised equipment the almost complete skull could only be partially secured.
The analyses revealed limited support for local phenotypic structuring of the soft grass mouse, A. mollis, given the lack of consistent morphological differentiation of the skull across environments.
Since conclusive evidence from randomised trials is lacking, the clinical benefit of helmet therapy compared with the natural course of skull deformation remains unknown.
These larvae are small, transparent and lack a skull, which makes it possible to record the activity of the cerebellum using tiny glass electrodes.
