page_title: Pterosaur
section_title: Pelvis
hierarchical_section_title: Pterosaur / Description / Pelvis
caption_attribution_description: English: A photograph of partial specimen American Museum of Natural History (AMNH) 22555, posterior dorsal vertebrae, and the sacrum and pelvis (both iliae, and right ischium and pubis) of Anhanguera sp. (formerly often assigned to Anhanguera santanae),&#91;1&#93; from the Early Cretaceous Romualdo Formation (former Romualdo Member of the Santana Formation) of NE Brazil in dorsal view. ↑ cf. fig.&#160;2A (also hosted at Commons), Table 2, and paragraph 50 in: Felipe L. Pinheiro​, Taissa Rodrigues (2017): Anhanguera taxonomy revisited: is our understanding of Santana Group pterosaur diversity biased by poor biological and stratigraphic control? PeerJ 5:e3285, doi:10.7717/peerj.3285
context_page_description: Pterosaurs were flying reptiles of the extinct clade or order Pterosauria. They existed during most of the Mesozoic: from the late Triassic to the end of the Cretaceous. Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.
  There were two major types of pterosaurs. Basal pterosaurs were smaller animals with fully toothed jaws and, typically, long tails. Their wide wing membranes probably included and connected the hind legs. On the ground, they would have had an awkward sprawling posture, but their joint anatomy and strong claws would have made them effective climbers, and they may have lived in trees. Basal pterosaurs were insectivores or predators of small vertebrates. Later pterosaurs evolved many sizes, shapes, and lifestyles. Pterodactyloids had narrower wings with free hind limbs, highly reduced tails, and long necks with large heads.
context_section_description: The pelvis of pterosaurs was of moderate size compared to the body as a whole. Often the three pelvic bones were fused. The ilium was long and low, its front and rear blades projecting horizontally beyond the edges of the lower pelvic bones. Despite this length, the rod-like form of these processes indicates that the hindlimb muscles attached to them were limited in strength. The, in side view narrow, pubic bone fused with the broad ischium into an ischiopubic blade. Sometimes, the blades of both sides were also fused, closing the pelvis from below and forming the pelvic canal. The hip joint was not perforated and allowed considerable mobility to the leg. It was directed obliquely upwards, preventing a perfectly vertical position of the leg.
  The front of the pubic bones articulated with a unique structure, the paired prepubic bones. Together these formed a cusp covering the rear belly, between the pelvis and the belly ribs. The vertical mobility of this element suggests a function in breathing, compensating the relative rigidity of the chest cavity.
caption: An anhanguerid pelvis seen from above, with the right side rotated towards the viewer
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