In lecture teacher beleives that argument in the reading passage are not strong enough to conclude that dinosaurs were endotherms.
First, polar regions in past were much warmer than polar region today. There is climate cylcle in polar region, warm season and cold season. Polar dinosaurs might have lived in polar regions in hot season and migrated to different place in coldern season. Or polar dinosaurs might have hibrenated during colder season as most of modern reptiles do. So, there might be no need to maintain body temperature.
Furtherore, positioning of legs under body is not an indication of that dinosaurs were endotherms. It does not dinosaurs were high energy endotherms. Legs might be underneath body to support more weight that dinosaurs possess. More weight and large size have many other advantages and benefits.
Moreover, while dinosaurs possess haversian canals like endotherms they also possess growth rings. Growth rings are thickening of bones when muscles are not growing rapidly. This is indication that dinosaurs muscles might not have grown rapidly in colder season which is not a charecteristic of endotherms. Endotherms maintain a constant body temperature even in colder season and their muscles grow rapidly despite of seasons. Growth rings are not found on the body of endotherms.
So, it is diffucult to reach a conclusion from these argument more information is needed to qualify that dinosaurs were endotherms.
In lecture teacher
beleives
that argument in the reading passage are not strong
enough
to conclude
that dinosaurs were endotherms.
First
,
polar
regions
in past were much warmer than
polar
region
today
. There is climate
cylcle
in
polar
region
, warm
season
and
cold
season
.
Polar
dinosaurs
might
have
lived
in
polar
regions
in hot
season
and migrated to
different
place in
coldern
season
. Or
polar
dinosaurs
might
have
hibrenated
during colder
season
as most of modern reptiles do.
So
, there
might
be no need to maintain
body
temperature.
Furtherore
, positioning of legs under
body
is not an indication of that dinosaurs were endotherms. It does not dinosaurs were high energy endotherms. Legs
might
be underneath
body
to support more weight that dinosaurs possess. More weight and large size have
many
other advantages and benefits.
Moreover
, while dinosaurs possess
haversian
canals like endotherms they
also
possess growth rings. Growth rings are thickening of bones when muscles are not growing
rapidly
. This is indication that dinosaurs muscles
might
not have grown
rapidly
in colder
season
which is not a
charecteristic
of endotherms. Endotherms maintain a constant
body
temperature even in colder
season
and their muscles grow
rapidly
despite of
seasons
. Growth rings are not found on the
body
of endotherms.
So
, it is
diffucult
to reach a conclusion from
these argument
more information
is needed
to qualify that dinosaurs were endotherms.