| Summary: | 2018 Spring. Includes bibliographical references. Bioinspired material design draws inspiration for improved technologies from unique functional adaptations found in nature. Grizzly bear (Ursus arctos horribilis), cave bear (Ursus spelaeus), edmontosaur (Edmontosaurus annectens) (Edmontosaurusregalis), and bighorn sheep (Ovis canadensis) exhibit unique functional examples of porous bone structures. Grizzly bear trabecular bone does not lose bone density during long periods of disuse. Cave bears, being larger than grizzly bears, give a unique perspective of trabecular bone property scaling relationships in animals from the near past. Edmontosaurs were expected to have grown to gigantic sizes weighing 7936±1991 kg creating a unique high force loading environment in dinosaur trabecular bone. Bighorn sheep butt heads during the mating season routinely generating near 100g accelerations and approximately 3400N forces in their horn core bone during impact. Morphological trabecular bone properties of bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), and trabecular number (Tb.N) were examined using micro-computed tomography (µCT) imaging for the underlying trabecular bone in the proximal tibias of grizzly bear, cave bear, and edmontosaurus animals. Morphological bone properties were compared against body mass scaling relationships from extant mammals. Cave bear trabecular bone was found to have larger BV/TV and Tb.Th than modern grizzly bears. The larger BV/TV may indicate environmental drivers on cave bear trabecular bone properties. To our knowledge, the measurement of dinosaur trabecular bone properties is a novel concept. Adult edmontosaur BV/TV was measured at an average greater than 60% which was significantly different from extant species BV/TV values. Additionally, adult edmontosaurus Tb.Th, and Tb.Sp were measured at comparable values to small mammals. The difference in edmontosaur BV/TV from extant mammals may be a potential clue in why extant terrestrial animals do ...
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