The semicircular crest (LS) and uncinate process (PU) in baboons (Papio anubis) across age, viewed in a coronal plane. A Schematic illustration of a mid-fetal specimen (CRL 115 mm), redrawn after Maier (2000, fig. 5.4, serial section # 124-2). The cartilaginous LS and PU are visible. B–E µCT cross sections of the ethmoidal region. B Late fetal specimen (Papio107, 150 days gestation), showing an osseous LS. C One year, 32 days old specimen (Papio108), showing an ossified LS and PU. D Adult individual (amnh:mammals:m-51380) showing both structures. Abbreviations: CC, cavum cranii; dP2, deciduous upper 2nd premolar; ET I, ethmoturbinal I; LA, lamina anterior of ET I; LAP, processus anterior of the LA of ET I; MT, maxilloturbinal; PN, paries nasi; SN, septum nasi. Scale bars: 10 mm.