@article{3c202fb06a754611a62d3d1507d7e50b,
title = "Growing up Tyrannosaurus rex: Osteohistology refutes the pygmy “Nanotyrannus” and supports ontogenetic niche partitioning in juvenile Tyrannosaurus",
abstract = "Despite its iconic status as the king of dinosaurs, Tyrannosaurus rex biology is incompletely understood. Here, we examine femur and tibia bone microstructure from two half-grown T. rex specimens, permitting the assessments of age, growth rate, and maturity necessary for investigating the early life history of this giant theropod. Osteohistology reveals these were immature individuals 13 to 15 years of age, exhibiting growth rates similar to extant birds and mammals, and that annual growth was dependent on resource abundance. Together, our results support the synonomization of “Nanotyrannus” into Tyrannosaurus and fail to support the hypothesized presence of a sympatric tyrannosaurid species of markedly smaller adult body size. Our independent data contribute to mounting evidence for a rapid shift in body size associated with ontogenetic niche partitioning late in T. rex ontogeny and suggest that this species singularly exploited mid- to large-sized theropod niches at the end of the Cretaceous.",
author = "Woodward, {Holly N.} and Katie Tremaine and Williams, {Scott A.} and Zanno, {Lindsay E.} and Horner, {John R.} and Nathan Myhrvold",
note = "Funding Information: G. Liggett, G. Smith, and D. Milton with the Bureau of Land Management (permits MTM 90904 and MTM 95725) granted excavation permits and histology processing permission for BMRP specimens. D. Carlson, M. Householder, D. Mauro, and J. Peterson conducted fossil preparation of BMRP 2002.4.1 and BMRP 2006.4.4. J. Mathews provided access to BMRP specimens. J. Scannella and A. Atwater (MOR) allowed access to T. rex histology thin sections. Ostrich and alligator thin section images are from specimens reposited at MOR. E. Lamm (MOR) produced the tibia thin sections of BMRP 2006.4.4 and the femur thin sections of BMRP 2002.4.1 for a previous study. N. Carroll granted permission to histologically examine CCM V33.1.15. G. Wilson, T. Carr, S. Brusatte, and T. Holtz provided helpful discussions. C. Tuck and B. Harrison discovered BMRP 2002.4.1. D. Breese and A. Breese discovered BMRP 2006.4.4. We are also thankful to M. Henderson, L. Crampton, and S. Moore. Funding: Funding was provided by the Myhrvold Family Charitable Fund, Oklahoma State University Center for Health Sciences, J. Brost and B. Brost, S. Landi, C. Vittore, B. Williams and C. Williams, the Institute of Museum and Library Services, Illinois Department of Natural Resources, Rockford Publisher Copyright: Copyright {\textcopyright} 2020 The Authors.",
year = "2020",
month = jan,
day = "1",
doi = "10.1126/sciadv.aax6250",
language = "English",
volume = "6",
journal = "Science Advances",
issn = "2375-2548",
publisher = "American Association for the Advancement of Science",
number = "1",
}