In 1991 and 1996 " proavis " or " protoavis " models were proposed by respectively Samuel Tarsitano and Alan Feduccia, both adherents of the " thecodont " hypothesis about the origins of birds.
12.
The term " thecodont ", now considered an obsolete term, was first used by the English paleontologist Richard Owen in 1859 to describe Triassic archosaurs, and it became widely used in the 20th century.
13.
In the case of mosasaurs though, they differ from the thecodont dentition pattern of archosaur and mammals because mosasaurs show true ankylosis and not a fibrous tooth attachment via periodontal ligament that s usually found in mammals and archosaurs.
14.
The description of the basal ornithodires " Lagerpeton " and " Lagosuchus " in the 1970s provided evidence that linked thecodonts with dinosaurs, and contributed to the disuse of the term " Thecodontia ", which many cladists consider an artificial grouping.
15.
Though the end-Triassic extinction event was not equally devastating in all terrestrial ecosystems, several important clades of thecodonts ) disappeared, as did most of the large labyrinthodont amphibians, groups of small reptiles, and some synapsids ( except for the proto-mammals ).
16.
This, in spite of their upright posture, rendered them only slightly more mobile than sprawling reptiles . " Desmatosuchus " possessed both of these features, along with its long femur and elongate pubis, making it more mobile than most thecodonts of its time.
17.
Because they are considered a " basal stock ", thecodonts are paraphyletic, meaning that they form a group that does not include all descendants of its last common ancestor : in this case, the more derived crocodilians and birds are excluded from " Thecodontia " as it was formerly understood.
18.
The dentition of Stegoceras was heterodont ( differentiated ) and thecodont ( placed in sockets ) . "-Plainer English is better where possible without losing meaning, so why not something like, " Stegoceras had teeth that were heterodont ( differentiated ) and thecodont ( placed in sockets ) . "?
19.
The dentition of Stegoceras was heterodont ( differentiated ) and thecodont ( placed in sockets ) . "-Plainer English is better where possible without losing meaning, so why not something like, " Stegoceras had teeth that were heterodont ( differentiated ) and thecodont ( placed in sockets ) . "?
20.
In their review of putative euparkeriids from China, Richard Butler and colleagues concluded that " Wangisuchus " is a " nomen dubium " at Archosauriformes indeterminate because its holotype lacked diagnostic characters, even though the thecodont tooth implantation pointed to a closer relationship to Archosauria than to " Proterosuchus ".
