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Anatomical terms used in this paper. Cervical vertebrae are neck vertebrae. Dorsal vertebrae are the vertebrae of the trunk, and they support the ribs. The sacrum consists of fused sacral vertebrae, and it is the point of attachment of the pelvis to the vertebral column. The ilium is the bone of the pelvis that attaches to the sacrum. Caudal vertebrae are tail vertebrae. All vertebrae have a centrum, or body, which connect to the vertebrae ahead of and behind them. Above the centrum is the neural canal, the opening through which the spinal cord passes. The neural canal is surrounded and protected by the neural arch. Above the neural arch is the neural spine, which is the point of attachment of ligaments and muscles that help support the body. The bone in the upper part of the forelimb is the humerus. The skeleton shown here is Brachiosaurus . The cervical vertebra, BYU 12867, is also from Brachiosaurus , and it is 94 cm long. The dorsal vertebra, OMNH 1382, is from Apatosaurus , and it is 93 cm tall.
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... the largest animals to ever walk on land. They were marvels of biological engineering, and that efficiency of design is especially evident in their , the bones that make up the backbone. The vertebrae of most animals are basically cylinders, with an arch of bone to protect the spinal cord and a few odd bumps that connect to muscles, ribs, or other vertebrae. The , or form, of the vertebrae of sauropods follows the same basic plan (Figure 1), but the usual cylinders and arches of the vertebrae are broken down into more complex shapes. The points and edges of the vertebrae are connected by ridges and plates of bone, which are called vertebral (Figure 2). In addition, the or “bodies” of the vertebrae may have deep pits or large holes that open into internal chambers. These laminae and cavities are often considered to be adaptations to lighten the animal by reducing its mass (Osborn, 1899; Hatcher, 1901; Gilmore, 1925). Furthermore, the complex arrangement of laminae and cavities in the vertebrae varies from one species to the next, and so they have been useful in reconstructing the evolution of sauropods (McIntosh, 1990; Wilson, 1999). The light construction of sauropod vertebrae and the hollow spaces inside them are not unique among animals. Similar vertebrae are present in animals that we see every day: birds. The vertebrae of most birds are hollow and filled with air. The bones are filled with air because they are connected to the lungs by a series of air-filled tubes and sacks. Things that have air inside them—like the tires of an automobile—are said to be . In most birds, at least part of the skeleton is pneumatic. The complex vertebrae of sauropod dinosaurs resemble those of birds, only they are much larger. But they have features that are only found in pneumatic bones, so paleontologists infer that when the sauropods were alive their vertebrae were also filled with air. ...
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Deinocheirus is a bizarre and unique theropod dinosaur. The holotype of Deinocheirus was discovered in 1976, but its characteristics and phylogenetic position remained largely enigmatic due to the scarcity of fossil material. This changed in 2014 when Lee et al. described two additional specimens, providing a deeper insight into this mysterious creature. Notably, the smaller specimen MPC-D 100/128 preserved a relatively complete dorsal vertebra with hyperelongated neural spines, reaching up to 8.5 times the height of the corresponding centra. This suggests that Deinocheirus possessed a raised dorsal sail or hump-like structure. Elongated neural spines have evolved multiple times in dinosaurs, including in ornithopods of ornithischians as well as theropods and sauropods of saurischians, with various hypothesized functions such as thermoregulation, fat storage, or sexual display. However, previous research on the neural spines of Deinocheirus has been limited to brief description, lacking detailed analysis and leaving the morphology and function of these dorsal structures poorly understood. To better understand the possible dorsal structure of Deinocheirus and its ecological role, this study examines the dorsal neural spines of Deinocheirus and 26 other dinosaurs. Through measurement and comparative analyses, we categorize the height and width of neural spines into different categories. Our comparison reveal that the neural spines of Deinocheirus are most similar to those of Spinosaurus and Ouranosaurus, with a height ratios exceeding 7 and overall morphology closer to the latter. Additionally, the anteroposterior width of neural spines of Deinocheirus is slightly narrower than that of Spinosaurus and Ouranosaurus. Based on these data and previous studies, we infer that the hyperelongated neural spines of Deinocheirus may serve dual functions: supporting a sail related to aquatic habits and a hump associated with an intricate interspinous ligament system, potentially for fat storage to aid in surviving dry seasons. Finally, we discuss avenues for future research, such as bone histology and finite element analysis, which could provide further insights into the morphology and function of the neural spines of Deinocheirus.