In
this given set of materials, there is discrepancy between the view of
the lecturer and the author over the issue of Lambeosaurus. With three
cogent explanations, the lecturer raises objections to the alleged functions of
its axe-shaped crest.
To
start with, the lecturer debunks the author's first conjecture since it is
highly doubtful. To elaborate in detail, the lecturer claims that most reptiles
including this dinosaur use a certain behavior or sounds to attract the opposite sex by giving an example of a crocodile.
This is in direct opposition to the author's claim that the crests helped the
creatures to obtain a mate.
On
top of that, the lecturer also indicates dissent over the author's point
on the crests of Lambeosaurus. The lecturer sounds convinced that the
author is making a manifest error on a function
of the crests since fossil evidence shows that position of a crest was backward and it
was hollow inside, which means that it would not have seemed to be appropriate
for combat. However, the author clarifies that the crests served as a
protective helmet to defend and a weapon to attack.
Thirdly,
the lecturer goes to expound the author's idea on a use of the crests. The
lecturer mentions its size to corroborate this opinion. She adds that it was
too small compared to the dinosaur's body size to store a lot of oxygen.
This counters the author's final theory that the Lambeosaurus would have used
its crest to store oxygen and respired with it while eating aquatic plants
underwater.