Using the comparative method, they pointed out some similarities to basal Euornithopoda : a small antorbital fenestra; the foramen on the quadratojugal; a large quadratic foramen; and the absence of an external fenestra in the lower jaw.
32.
The quadratojugal has a robust horizontal front branch and a thin short vertical branch, only half as tall as the quadrate shaft . There is no clear " foramen paraquadraticum ", opening between the quadrate and quadratojugal.
33.
The quadratojugal has a robust horizontal front branch and a thin short vertical branch, only half as tall as the quadrate shaft . There is no clear " foramen paraquadraticum ", opening between the quadrate and quadratojugal.
34.
One consequence has been Romer's suggestion of the alternative order Younginiformes to be applied strictly to those forms with the primitive diapsid form, in particular, a complete lowermost arch as the quadratojugal and jugal bones of the skull meet.
35.
It has a distinctive narrow snout, a long frill ( squamosal and parietal bone ) with large elongated openings, long, robust epijugal " horns ", long, brow horns, as well as a bifurcated quadratojugal-squamosal contact.
36.
"Shamosaurus scutatus " shares many rostrum ( the snout is tongue-shaped and narrow in top view ), quadratojugal protuberances ( cheek horns ), and caudolaterally directed paroccipital processes ( extensions of the rear skull obliquely pointing to behind and sideways ).
37.
They include parts of the skull ( right premaxilla, right maxilla, right lacrimal bone, right postorbital and possible front branch of the right quadratojugal ), the gastralia, one complete rib and four rib fragments, a finger phalanx, both fibulae, a right astragalus and a right calcaneum.
38.
The remains include the lower jaw and back half of the skull, along with neck and back vertebrae, and various limb elements . " Animantarx " is characterized by a unique combination of features, including a highly domed skull back, small horns on the postorbital and quadratojugal bones of the skull, and a mandible which is only armoured on half of its length.
39.
Several features indicate that " Smok " is an archosaur, including serrated teeth, a contact between the jugal and quadratojugal bones at the back of the skull, a hole in front of the eye socket called the antorbital fenestra, maxillae bones in the upper jaw that connect along their palatal processes, and a rounded projection on the upper part of the femur bone.
40.
Some distinguishing traits of " Jeholosaurus " include : enlarged laterodorsal nasal foramina; a quadratojugal fenestra more than 25 % maximum quadratojugal length; a quadratojugal less than 30 % of skull height; a predentary with almost 150 % of premaxillary body length; a dentary extending posteriorly almost to the posterior border of the angular; and the claw of the third toe being longer than the other third toe phalanges.
