title: Chemistry supports the identification of gender-specific reproductive tissue in Tyrannosaurus rex.
abstract: Medullary bone (MB), an estrogen-dependent reproductive tissue present in extant gravid birds, is texturally, histologically and compositionally distinct from other bone types. Phylogenetic proximity led to the proposal that MB would be present in non-avian dinosaurs, and recent studies have used microscopic, morphological, and regional homologies to identify this reproductive tissue in both theropod and ornithischian dinosaurs. Here, we capitalize on the unique chemical and histological fingerprint of MB in birds to characterize, at the molecular level, MB in the non-avian theropod Tyrannosaurus rex (MOR 1125), and show that the retention of original molecular components in fossils allows deeper physiological and evolutionary questions to be addressed.
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh NC 27695, USA.|North Carolina Museum of Natural Sciences, Raleigh NC 27601, USA.
authors.forename: Mary Higby
authors.initials: MH
authors.lastname: Schweitzer
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh NC 27695, USA.
authors.forename: Wenxia
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Department of Biological Sciences, North Carolina State University, Raleigh NC 27695, USA.|North Carolina Museum of Natural Sciences, Raleigh NC 27601, USA.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Zanno
authors.affiliation: Department of Anatomy, Des Moines University, Des Moines IA 50312, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Werning
authors.affiliation: Department of Agrobiology, Niigata University, Niigata 9502181, Japan.
authors.forename: Toshie
authors.initials: T
authors.lastname: Sugiyama
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000737:chemistry*; D002645:Chickens / Q000033:anatomy & histology; D025061:Dinosaurs / Q000033:anatomy & histology*; D005260:Female; D005580:Fossils; D007632:Keratan Sulfate / Q000032:analysis*; D012098:Reproduction; D012727:Sex Characteristics; D012732:Sex Determination Analysis; D020310:Struthioniformes / Q000033:anatomy & histology
chemical_list: D007632:Keratan Sulfate