Both the lecturer and the reading passage discuss Sauropods, dinosaurs with long necks. The lecturer casts doubt on the author's assertion on several reasons why Sauropods' neck is held horizontally, by presenting three counter-arguements.
First, the lecturer asserts that the explanation that sauropod's neck was held horizontally because of its large heavy tail, is disputable. This is because Sauropod's tail is not heavy to provoke other body issues. To be specific, as Suaropod's tail was hollow and contained air, the neck would not have to be positioned horizontally to counterweight its tail. This counters the author's claim that sauropod's neck was held horizontally to offset the weight of its tail.
Second, the lecturer claims that marine vegetation of sauropods is not a convincing reason to explain its position of the neck. He says that because there was no sufficient vegetation for large sauropods to consume, sauropods seeked for a variety of plants and not only for marine plants. Actually, sauropods would need a vertical neck to eat tree leaves and not a horizontal one. This counters the author's claim that horizontal neck posture is due to sauropod's marine vegetation.
Lastly, the lecturer argues that the theory that sauropods are unable to raise its neck vertically is controversial. This is because many dinosaurs, including sauropods, posessed strong shoulder muscles that are connected to its neck. Therefore, sauropods would have used its shoulder muscles to raise its neck vertically. This counters the author's statement that sauropods' weak muscle to raise its neck, maintained a horizontal neck. |