with an outer row of moderate canines, slightly larger anteriorly; 1-3 irregular series of slightly smaller teeth behind outer row on anterior half of dentary
The splenial appears to be fused with the dentary
in all specimens, and does not extend posteriorly beyond the apex of the coronoid in specimens where this character can be evaluated.
First tooth in outer dentary
row a large canine followed by two or three conical teeth (first and third smaller and second similar to anteriormost canine) followed by row of 28 - 44 small conical teeth.
Teeth on proximal end of dentary
similar to those on premaxilla.
The wear facets are more expanded mesiodistally and inclined, likewise slightly mesially in maxillary teeth and distally in dentary
teeth (Galton, 1974: figs.
The extended lower jaw is heavily pigmented throughout development and melanophores extend laterally along the dentary
Second, Sinotyrannus possesses several unique features shared with basal tyrannosauroids such as Guanlong and Proceratosaurus, including an enlarged external naris, midline nasal crest, an anterior ramus of the maxilla, and a sharp and deep neurovascular groove on the dentary
(Xu et al.
Teeth appeared along the premaxilla and dentary
0% HL, about equal in length to blind-side mandible; teeth conical and slightly lobate or truncate, largest are anterior becoming gradually smaller posteriorly, fewer on ocular-side premaxilla and dentary
, 4-10 on ocular-side premaxilla, 20-27 on blind-side premaxilla, 8-15 on ocular-side dentary
, 20-29 on blind-side dentary
; gill rakers of first arch moderately slender to broad and robust, 6-14 total, 1-6 on upper and 4-9 on lower arch; gill rakers of second arch broad and robust, 6-14 total, 0-4 on upper and 5-13 on lower arch; dorsal orbit round (nearly equal to eye length) to elliptical (posterior rim elongate and much greater than eye length), orbit lenth 22.
and retroarticular begin to differentiate at 9 DPH (2.
Teeth small, conical and recurved; premaxilla bearing a single row of teeth posteriorly, and 1-2 rows anteriorly, edentulous near symphysis; teeth on dentary
in an irregular single row near symphysis continuing as a narrow band of 2-3 rows posteriorly; vomerine teeth larger than those on jaws, arranged in a large triangular patch; teeth on palatine arranged in a band of 2-3 rows; tongue with a band of 2-4 rows of densely-set teeth on glossohyal.
Teeth small, although those of pterygoid and rear portion of vomer slightly enlarged; teeth in three rows on maxilla, tapering to two rows posteriorly; teeth in about five irregular rows on dentary
, tapering to a single row posteriorly; intermaxillary-vomerine patch with 3-4 rows of teeth anteriorly, the tooth patch tapering posteriorly and nearly as long as maxillary row; pterygoid teeth in single row.