Speaker: Mike Taylor; University of Bristol Earth Sciences.
Mike will be looking at aspects of the anatomy of really big animals, including dinosaurs and modern mammals, to see how dinosaur evolution found solutions to problems that stymied it in the mammalian world.
About sauropods, he says:
The necks of sauropod dinosaurs were by far the longest in history, exceeding 15m. Four very different sauropod groups evolved 10m necks. By contrast, the neck of the giraffe, the longest of any extant animal, reaches only 2.4m. The necks of theropods and pterosaurs attained at most 3m. (Even among aquatic animals, the record is only 7m for elasmosaurs.)
Seven factors contributed to extraordinary neck lengths in sauropods: their sheer size, quadrupedal stance, small heads, cervical vertebra count, elongation of individual vertebrae, air-sacs and vertebral architecture. Cervical vertebral innovations included: extreme pneumatisation, which lightened the neck and increased bending resistance; long cervical ribs, which enabled heavy muscles to be shifted back towards the torso; and, in several groups, bifid neural spines, which aided stability by shifting muscles and ligaments laterally.
But other aspects of sauropod cervical anatomy remain puzzling: low neural spines reduced the lever arm of the muscles that held the neck up; low-hanging cervical ribs increased neck bulk; and muscle attachments on the upper parts of the vertebrae were not posteriorly elongated like those on the lower parts. These apparent flaws suggest our understanding of sauropod neck mechanics remains incomplete.