Endotherms are animals such as modern birds and mammals that keep their body temperatures constant. For instance, humans are endotherms and maintain an internal temperature of 37°C, no matter whether the environment is warm or cold. Because dinosaurs wer

In lecture teacher believes 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.