Figure 21 in A high-resolution growth series of Tyrannosaurus rex obtained from multiple lines of evidence

Figure 21 Sex dimorphs and the taxon "Tyrannosaurus "x"" of Larson (2008) mapped onto the ontogram of Tyrannosaurus rex. A transitional pattern is not seen between gracile and robust morphs; if sexual dimorphism was present, then the "gracile" and "robust" morphs should group along separate branches, which is not seen. Also, specimens referred to the taxon "T. "x"" do not form a clade, indicating that it is not a valid taxon. The pattern seen here is what is expected for a species without sexual dimorphism. Specimens considered in Larson (2008) as gracile are in boldface italics with a boldface "G"; specimens considered in Larson (2008) as robust are in boldface with a boldface "R"; specimens considered in Larson (2008) as referable to "T. "x"" are in italics and marked with an "X". Full-size DOI: 10.7717/peerj.9192/fig-21