TL;DR: A new sampling technique for fossil bone (coring with a 5/8” bit) was used to sample longbones of all four sauropod genera from the Upper Jurassic Tendaguru beds of Tanzania for paleohistological study, showing a common growth pattern in which growth is determinate but sexual maturity is achieved well before maximum size is reached.
Abstract: A new sampling technique for fossil bone (coring with a 5/8” bit) was used to sample longbones of all four sauropod genera from the Upper Jurassic Tendaguru beds of Tanzania for paleohistological study. Brachiosaurus and Barosaurus are represented by growth series of humeri and femora, while Dicraeosaurus could be sampled in fewer specimens and only one bone of Janenschia was available. Although all samples are dominated by fibrolamellar bone tissue, taxa can be distinguished by the degree and nature of bone remodeling and the presence and spacing of a peculiar kind of growth line (here termed “polish lines”). In addition, Barosaurus bone revealed two types of histology, tentatively interpreted as sexual morphs. The Tendaguru sauropods show a common growth pattern in which growth is determinate but sexual maturity is achieved well before maximum size is reached. For Brachiosaurus and Barosaurus, size at sexual maturity can be estimated and was reached at about 40% and 70% maximum size, respective...
TL;DR: This book discusses the evolution of Sauropod Biology and the Evolution of Gigantism, and the role of carbon Isotope Analysis on Teeth, Bones, and Plants.
Abstract: List of Contributors Preface List of Institutional Abbreviations Introduction 1. Sauropod Biology and the Evolution of Gigantism: What Do We Know? / Marcus Clauss Part 1. Nutrition 2. Sauropod Feeding and Digestive Physiology / Jurgen Hummel and Marcus Clauss 3. Dietary Options for the Sauropod Dinosaurs from an Integrated Botanical and Paleobotanical Perspective / Carole T. Gee 4. The Diet of Sauropod Dinosaurs: Implications of Carbon Isotope Analysis on Teeth, Bones, and Plants / Thomas Tutken Part 2. Physiology 5. Structure and Function of the Sauropod Respiratory System / Steven F. Perry, Thomas Breuer, and Nadine Pajor 6. Reconstructing Body Volume and Surface Area of Dinosaurs Using Laser Scanning and Photogrammetry / Stefan Stoinski, Tim Suthau, and Hanns-Christian Gunga 7. Body Mass Estimation, Thermoregulation, and Cardiovascular Physiology of Large Sauropods / Bergita Ganse, Alexander Stahn, Stefan Stoinski, Tim Suthau, and Hanns-Christian Gunga Part 3. Construction 8. How to Get Big in the Mesozoic: The Evolution of the Sauropodomorph Body Plan / Oliver W. M. Rauhut, Regina Fechner, Kristian Remes, and Katrin Reis 9. Characterization of Sauropod Bone Structure / Maitena Dumont, Anke Pyzalla, Aleksander Kostka, and Andras Borbely 10. Finite Element Analyses and Virtual Syntheses of Biological Structures and Their Application to Sauropod Skulls / Ulrich Witzel, Julia Mannhardt, Rainer Goessling, Pascal de Micheli, and Holger Preuschoft 11. Walking with the Shoulder of Giants: Biomechanical Conditions in the Tetrapod Shoulder Girdle as a Basis for Sauropod Shoulder Reconstruction / Bianca Hohn 12. Why So Huge? Biomechanical Reasons for the Acquisition of Large Size in Sauropod and Theropod Dinosaurs / Holger Preuschoft, Bianca Hohn, Stefan Stoinski, and Ulrich Witzel 13. Plateosaurus in 3D: How CAD Models and Kinetic-Dynamic Modeling Bring an Extinct Animal to Life / Heinrich Mallison 14. Rearing Giants: Kinetic-Dynamic Modeling of Sauropod Bipedal and Tripodal Poses / Heinrich Mallison 15. Neck Posture in Sauropods / Andreas Christian and Gordon Dzemski Part 4. Growth 16. The Life Cycle of Sauropod Dinosaurs / Eva-Maria Griebeler and Jan Werner 17. Sauropod Bone Histology and Its Implications for Sauropod Biology / P. Martin Sander, Nicole Klein, Koen Stein, and Oliver Wings Part 5. Epilogue 18. Skeletal Reconstruction of Brachiosaurus brancai in the Museum fur Naturkunde, Berlin: Summarizing 70 Years of Sauropod Research / Kristian Remes, David M. Unwin, Nicole Klein, Wolf-Dieter Heinrich, and Oliver Hampe Appendix: Compilation of Published Body Mass Data for a Variety of Basal Sauropodomorphs and Sauropods Index
TL;DR: The first complete sauropod skull from the Cretaceous of the Americas is described, Abydosaurus mcintoshi, known from Dinosaur National Monument, USA, and may signal a shift towards elevated tooth replacement rates and high-wear dentition.
Abstract: Sauropod dinosaur bones are common in Meso- zoic terrestrial sediments, but sauropod skulls are exceed- ingly rare—cranial materials are known for less than one third of sauropod genera and even fewer are known from complete skulls. Here we describe the first complete sauropod skull from the Cretaceous of the Americas, Abydosaurus mcintoshi, n. gen., n. sp., known from 104.46±0.95 Ma (megannum) sediments from Dinosaur National Monument, USA. Abydosaurus shares close ancestry with Brachiosaurus, which appeared in the fossil record ca. 45 million years earlier and had substantially broader teeth. A survey of tooth shape in sauropodomorphs demonstrates that sauropods evolved broad crowns during the Early Jurassic but did not evolve narrow crowns until the Late Jurassic, when they occupied their greatest range of crown breadths. During the Cretaceous, brachiosaurids and other lineages independently underwent a marked diminution in tooth breadth, and before the latest Creta- ceous broad-crowned sauropods were extinct on all continental landmasses. Differential survival and diversifi- cation of narrow-crowned sauropods in the Late Cretaceous appears to be a directed trend that was not correlated with changes in plant diversity or abundance, but may signal a shift towards elevated tooth replacement rates and high- wear dentition. Sauropods lacked many of the complex herbivorous adaptations present within contemporaneous ornithischian herbivores, such as beaks, cheeks, kinesis, and heterodonty. The spartan design of sauropod skulls may be related to their remarkably small size—sauropod skulls account for only 1/200th of total body volume compared to 1/30th body volume in ornithopod dinosaurs.
TL;DR: Articulated digital reconstructions of two diplodocid sauropods revealed cervical poses and feeding envelopes that suggest that these sauroPods were adapted to ground feeding or low browsing, contrary to the view that diplodytids were high browsers.
Abstract: Articulated digital reconstructions of two diplodocid sauropods revealed cervical poses and feeding envelopes. The necks of Diplodocus and Apatosaurus were nearly straight but gently declined such that the heads, which were themselves angled downward relative to the neck, were close to ground level in their neutral, undeflected posture. Both necks were less flexible than conventionally depicted, and Diplodocus was less capable of lateral and dorsal curvature than Apatosaurus. The results suggest that these sauropods were adapted to ground feeding or low browsing, contrary to the view that diplodocid sauropods were high browsers.
TL;DR: The titanosaurid skull is interpreted as Camarasaurus-Iike, but with peg-like teeth restricted to the extremity of the jaws, which exhibit wear facets sharply inclined with respect to the labio-lingual axis.
Abstract: "The titanosaurid skull is interpreted as Camarasaurus-Iike, but with ""peg-like"" teeth restricted to the extremity of the jaws, which exhibit wear facets sharply inclined with respect to the labio-lingual axis. The last character is shared with Brachiosaurus Riggs and Pleurocoelus Marsh, and it is considered a probable synapomorphy of Titanosauriformes. Several cranial characters are considered synapomorphies of Titanosauria or a less inclusive group (long recurved paraoccipital processes, becoming slender downwards; reduced, narrow supratemporal fenestra), or synapomorphies within Titanosauridae (""peg-Iike"" teeth; teeth restricted ro the anterior region of the snout and mandibular symphysis perpendicular to the long axis of the lower jaw). Several characters, such as ""peg-like"" teeth restricted to the anterior region of the snout, wear facets sharply inclined with respect to the labiolingual tooth axis, and mandibular symphysis perpendicular to the long axis of the lower jaw, suggest that Nemegtosaurus mongoliensis Nowinski and Quaesitosaurus orientalis Kurzanov and Banikov are related to the Titanosauridae. ""Pleurocoelus"" sp., from the Lower Cretaceous of Texas and Utah, is considered a basal titanosaur by having procoelous anterior caudals, teeth with an intermediate morphology between Brachiosaurus and titanosaurids, and dorsal verterbrae with centro-parapophyseallamina and ventrally widened, sligthly forked infradiapophyseal Iarnina. Basal titanosaurs and other titanosaur-related sauropods had a wide distribution during the Early Cretaceous. The hypothesis that Alamosaurus sanjuanensis Gilmore is a Late Cretaceous inmigrant from South America is consistent with its phylogenetic position. The Saltasaurinae, in turn, represent an endemic group of South America. "