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 were reptiles, and modern reptiles are not endotherms, it was long assumed that dinosaurs were not endotherms. However, dinosaurs differ in many ways from modem reptiles, and there is now considerable evidence that dinosaurs were, in fact, endotherms.
Polar dinosaurs
One reason for believing that dinosaurs were endotherms is that dinosaur fossils have been discovered in polar regions. Only animals that can maintain a temperature well above that of the surrounding environment could be active in such cold climates.
Leg position and movement
There is a connection between endothermy and the position and movement of the legs. The physiology of endothermy allows sustained physical activity, such as running. But running is efficient only if an animal's legs are positioned underneath its body, not at the body's side, as they are for crocodiles and many lizards. The legs of all modern endotherms are underneath the body, and so were the legs of dinosaurs. This strongly suggests that dinosaurs were endotherms.
Haversian canals
There is also a connection between endothermy and bone structure. The bones of endotherms usually include structures called Haversian canals. These canals house nerves and blood vessels that allow the living animal to grow quickly, and rapid body growth is in fact a characteristic of endothermy. The presence of Haversian canals in bone is a strong indicator that the animal is an endotherm, and fossilized bones of dinosaurs are usually dense with Haversian canals.
The reading is about dinosaurs and provides three reasons to corroborate that dinosaurs were endotherms. However, the professor in the lecture explains that scientists do not agree with the arguments mentioned in the reading and claims these arguments aren’t approval.
First of all, the reading as a first reason to prove that dinosaurs were endotherms states dinosaurs’ fossils have been found in polar region and as just endotherms can live in cold environments, dinosaurs are endotherms. The professor rejected this evidence by discussing that polar region were warm part of the year that dinosaurs were live there but when the weather became cold they could not to migrate and they hibernated there like other reptiles. That’s why their fossils remained there.
Secondly, as a second reason the article bring this evidence that as dinosaurs’ fossils show that their legs had been beneath their body unlike the reptiles which their legs are at their bodies’ side, dinosaurs could have been run and this physical activity is just for endotherms. Therefore, the reading concludes dinosaurs were endotherms. Although, the professor is opposite of this evidence by saying that the position of their legs was because their weight. She adds it was big advantages for dinosaurs to became very large. Therefore, this position of legs helps them to endure their body weight.
Finally, Even though upon this reason that scrutiny of dinosaurs’ fossils shows there are Haversian canals in dinosaurs’ bones and this attribute is confined to endotherms, the professor in the lectures confirms this evidence but she mentioned that there are also growth rings in their bones. The growth rings show, during cold period, dinosaurs have not been grown. This pattern of growing that they had rapid growth during warm period and slow in cold period proves they were reptile.
Comments
In contrast to the reading…
In contrast to the reading passage, which emphasizes the endotherm animals and their specifications. The lecture focuses on explaining characteristics of endotherm animals. The professor disagrees with the text about characteristics of endotherm animals.
The passage explains that there is a one reason for admit that dinosaurs were endotherms and that evidence is fossils have been found in polar regions. However, professor points out that polar areas were much warm than today. Moreover, for that temperature problems the dinosaurs could not migrate for long distances about this cold weather.
Secondly, according to the text, running is effective if animal's legs are established underneath, not at the body's side. However, the professor contradict by saying that high energy endotherms is for running. Furthermore, if animal’s legs are positioned underneath, the animals grow fastly and being very large. Being large is an extra advantage.
Thirdly, the passage indicate that there is a connection between endothermy and bone structure and its called Haversian canals. These canals permit animal to grow fastly. However, the professor points out that animal's bones also have growth rings. There is an evidence which express that these rings causing of growing slowly even stop growing during cooling period.
Finally, in contrast to the reading passage's claims that dinosaurs were, in fact, endotherms. However, the professor reminds the students that these all kinds of growths is characteristics of animals which are not endotherms.
Sentence: Secondly, as a second reason the article bring this evidence that as dinosaurs' fossils show that their legs had been beneath their body unlike the reptiles which their legs are at their bodies' side, dinosaurs could have been run and this physical activity is just for endotherms.
Description: The fragment article bring this is rare
Suggestion: Possible agreement error: Replace bring with verb, past tense
Sentence: She adds it was big advantages for dinosaurs to became very large.
Description: The token to is not usually followed by a verb, past tense
Suggestion: Refer to to and became
Attribute Value Ideal
Score: 26 in 30
Category: Very Good Excellent
No. of Grammatical Errors: 2 2
No. of Spelling Errors: 0 2
No. of Sentences: 13 12
No. of Words: 299 250
No. of Characters: 1526 1200
No. of Different Words: 141 150
Fourth Root of Number of Words: 4.158 4.2
Average Word Length: 5.104 4.6
Word Length SD: 2.374 2.4
No. of Words greater than 5 chars: 109 80
No. of Words greater than 6 chars: 81 60
No. of Words greater than 7 chars: 61 40
No. of Words greater than 8 chars: 39 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 23 21.0
Sentence Length SD: 13.934 7.5
Use of Discourse Markers (%): 0.615 0.12
Sentence-Text Coherence: 0.381 0.35
Sentence-Para Coherence: 0.579 0.50
Sentence-Sentence Coherence: 0.122 0.07
Number of Paragraphs: 4 4