Fig. 3 in Growing up Tyrannosaurus rex: Osteohistology refutes the pygmy "Nanotyrannus" and supports ontogenetic niche partitioning in juvenile Tyrannosaurus

Fig. 3. The presence of an EFS at the periosteal surface of a long bone indicates skeletal maturity, while the absence of an EFS indicates that the bone is still growing at the time of death. (A) An EFS composed of tightly stacked birefringent LAGs (between blue arrowheads) at the periosteal surface of an Alligator mississippiensis. (B) The EFS (between blue arrowheads) in an ostrich (struthio camelus) is made of nearly avascular, birefringent parallel-fibered to lamellar primary tissue. (C) No EFS is present at the periosteal surface of the femur of BMRP 2002.4.1, (D) the tibia of BMRP 2002.4.1, (E) the femur of BMRP 2006.4.4, or (F) the tibia of BMRP 2006.4.4. All panels are shown in transverse thin section, with CPL.