Table 1. Specimens of Tyrannosaurus rex analysed in this study. (Specimen numbers are from the MOR, with catalogue numbers of labelled thin sections; tib, tibia; fem, femur; fib, fibula; L, length of bone (mm); C, circumference of bone (mm); Tcor, total cortical thickness; Tlag, cortical thickness with LAGs preserved; Tnon, cortical thickness without LAGs preserved; MR, medullary radius (marrow cavity from which bone has been eroded) = total radius minus cortical thickness; actual LAGs, number of LAGs that could be counted in Tlag; retroc LAGs, number of LAGs retrocalculated for Tnon. Methods of calcu- lation: (i) mean; (ii) maximum; (iii) penultimate; (iv) parabolic; and (v) incremental; for explanation see § 2.) specimensectionLCTcorTlagTnonMRactual LAGsretroc LAGscalibrated age methods of calculation and overall age estimates009 tibTI- 1 - C10704041616035410 –1114– 15 ± 1 (i), 8 – 10 (ii), 10 – 12 (iii) + 11 – 12009 tibTI- 1 - D10704042020045310 –1113 – 14 ± 1 (i), 9 – 11 (ii), 13 – 15 (iii) + 11 – 12555 tibTI- 1 a1200ca. 500262604374 – 1411 – 12 (ii), 14 (iii), 16– 18 (iv) + 14 ± 2555 tibTI- 1 b1200ca. 500272704374 – 1411 – 12 (ii), 14 (iii), 16– 18 (iv) + 14 ± 21125 femFe 1- L 2- B2 a10704333014164649 – 1115 – 17 (i)1125 femFe 1- L 2- B2 b107043322121038710 – 1517 – 18 (v), 20 –22 (ii) + 18 ± 21156 tibT 2 -1——381820—7——1156 tibT3 - 1——431132—7——1198 tibFe- 1 -B- 1——442222—103 – 4—1198 tibFe- 1 - A- 1——29290—8——1128 tibTI- 1112046426260446 – 74 – 1311 – 12 (v), 14 – 16 (ii), 18 – 20 (iii), 20 – 21 (i) + 16 ± 51128 tibTI- 2112046426260446 – 74 – 1311 – 12 (v), 14 – 16 (ii), 18 – 20 (iii), 20 – 21 (i) + 16 ± 51152 femLBF2 -1——442222—103 – 4—1152 femF 2 - 1——412615—102 – 3—1152 fibFi- 2——2211111‡ 175– 1024– 25(ii), 27 (iii), 22 (v) + 25 ± 2

Published as part of Horner, John R. & Padian, Kevin, 2004, Age and growth dynamics of Tyrannosaurus rex, pp. 1876 in Proceedings of the Royal Society, Series B 271 on page 1876, DOI: 10.1098/rspb.2004.2829, http://zenodo.org/record/3726770