2013)), 8-9 or more pairs of symphyseal teeth in dorsal view (12 pairs according to Benson et al. (wikipedia.org)
Data from these scans provide new anatomical information, such as the presence of branching vascular canals within the premaxilla and dentary, and an undescribed dorsal (quadrate) wing of the pterygoid hidden within matrix. (peerj.com)
Lower jaw2
and the absence of an external fenestra in the lower jaw. (wikipedia.org)
P. brachydeirus had approximately 70 teeth in the lower jaw (72 according to Benson et al. (wikipedia.org)
Traits2
However, they also noticed more derived euornithopod traits, such as the form of the greater and anterior trochanter of the thighbone, although the premaxilla not reaching the lacrimal, the high jaw joint and the premaxilla being on the same level as the maxilla, were again basal traits. (wikipedia.org)
Very basal ornithischian traits included the presence of six teeth in the premaxilla with only a short toothless sector in front and a short hiatus with the maxillary teeth. (wikipedia.org)
Ontogenetic2
Our analysis of 32 specimens has shown a pattern of ontogenetic tooth loss through the reduction of overall tooth counts from 13 to 10 tooth positions (Fig. 1I). (researchgate.net)
The ontogenetic reduction in tooth count in Opisthodontosaurus is difficult to quantify statistically because most of the dentaries are incomplete, making jaw length an ineffective metric by which to approximate size or age of the individual. (researchgate.net)
Ventral1
The deeply inset ventral margin in the maxilla suggests fleshy cheeks may have been present. (wikipedia.org)
Autapomorphies1
Species of this genus are differentiated from other pliosaurids based on seven autapomorphies, including teeth that are triangular in cross section. (wikipedia.org)
Anterior1
However, they also noticed more derived euornithopod traits, such as the form of the greater and anterior trochanter of the thighbone, although the premaxilla not reaching the lacrimal, the high jaw joint and the premaxilla being on the same level as the maxilla, were again basal traits. (wikipedia.org)
Nasals1
2001) and partial nasals and maxillae from the Middle Turonian of Kansas ( Terminonaris cf. (unl.pt)
Jaws2
A considerable portion of sphenodontian fossil diversity is represented only by fragmentary specimens of little systematic value, such as isolated jaws and teeth-e.g., refs. (nature.com)
1970) suggested that the addition of larger teeth at the rear of the dental rows in monophyodont lizards would be a way to maintain appropriate sized teeth in continuously growing jaws. (researchgate.net)
Refers3
The etymology of the specific name was not specified, but it probably refers to the shorter teeth of P. brachydeirus compared to teeth of other species then referred to Plesiosaurus. (wikipedia.org)
Tooth implantation should not be conflated with tooth attachment which refers to the tissue that attaches the tooth to the dentulous bone. (researchgate.net)
Tooth attachment refers to the tissues that attach teeth, whilst implantation refers to the orientation of the tooth relative to the jaw. (researchgate.net)
Position2
Most reptiles exhibit minimal change in tooth position and tooth count, with a few documented exceptions (e.g. (researchgate.net)
Reptilian dentitions tend to be homodont (Montanucci, 1968) readily masking any external anatomical evidence of a change in tooth position that would be associated with tooth replacement, as the new tooth would look very similar in size and shape to its predecessor. (researchgate.net)
High1
Opisthodontosaurus, but unexpectedly also revealed the presence of a high degree of posterior tooth migration throughout ontogeny. (researchgate.net)
Replacement1
Tooth implantation has been conflated with other tooth characteristics, such as replacement, attachment, and morphology. (researchgate.net)