Variation and sexual dimorphism in Tyrannosaurus rex Author Peter Larson text 2008 lndiana University Press Editor Peter Larson Editor Kenneth Carpenter Tyrannosaurus rex, the tyrant king 102 128 book chapter 21505 10.5281/zenodo.3942903 a6f10916-99f2-4d28-8fe6-cf38cde04291 3942903

Table 8.4. Comparison of Tyrannosaurid Skull Characters

Skull Character	Tyrannosaurus rex	Tyrannosaurus " x "	Tarbosaurus bataar	Tarbosaurus bataar Juvenile	Nanotyrannus lancensis	Gorgosaurus sp.	Albertosaurus sp.
Antorbital fossa	Very deep	Deep	Deep	Deep	Very shallow	Shallow	Shallow
Ventral antorbital maxillary ridge meets jugal	No	No	No	No	Yes	Yes	Yes
Maxillary fenestra reaches rostral margin of antorbital fossa (Carr et al. 2005)	Yes	Yes	Yes	Yes	No	No	No
Maxillary fenestra reaches ventral margin of antorbital fossa (Carr et al. 2005)	Yes	Approaches	Yes	Yes	No	No	Approaches
Vomer expansion	Lateral	Lateral	Lateral	?	Dorsoventral	Dorsoventral	?
Posterior dorsal Quadratojugal notch	No	No	No	No	Yes	Yes	No
Central dorsal quadratojugal notch	No	No	No	No	Yes	Yes	No
Anterior dorsal medial notch in quadratojugal (Carr and Williamson 2004)	Yes	?	No	?	No	No	No
Lachrymal horn (cornual process)	Absent	Absent	Absent	Absent	Present	Present	Present
Lachrymal shape	Inverted L	Inverted L	Inverted L	Inverted L	T	T	T
Quadrate—squamosal articulation	Double	Double	?	?	Single	Double	Single
Cranial nerve V-2 bounded by:	Maxilla and premaxilla	Maxilla and premaxilla	Maxilla and premaxilla	Maxilla and premaxilla	Maxilla only	Maxilla only	?
Anterior maxilla fossa at cranial nerve V-2	Maxilla and premaxilla	Maxilla and premaxilla	Maxilla and premaxilla	Maxilla and premaxilla	Maxilla only	Maxilla only	?