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 main topic of both the passage and the talk is whether dinosaurs were endotherms or not. According to the passage, there are tenable reasons that suggest they were endotherms; however, the lecturer finds the idea questionable, citing three reasons to repudiate the reasons addressed in the passage.
First, it is mentioned in the passage that since dinosaur fossils have been found in polar regions and only endotherms can survive low temperaures of polar regions, So they must be endotherms. However, the lecturer contradicts the author's view by pointing out that polar regions were much warmer than they are today in some months. He states that dinosaurs could even migrate or hibernate in cold months to survive and this does not prove that they were endotherms.
Seccond, the article posits that because their legs were under their body, the animal must have had the ability to run; therefore, this evidence prove that they must have been endotherms. On the contrary, the lecturer says that this position of legs was for supporting their huge weight and has nothing do with the ablity of running. So, it cannot concluded that they were endotherms.
Third, the author maintains that since they had Haversian canals which allows quick grow for endotherms, they must have been endotherms. Although the professor admits that they had Haversian canals, He opposes this assertion by explaining that their growth rings prove that their growth was slow and stopped in some durations which he says were cold seasons. He concluded that based on this evidence, they were not endotherms
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can survive low temperaures of polar regions
can survive at low temperatures of polar regions
this evidence prove that
this evidence proves that
Haversian canals which allows quick grow
Haversian canals which allow quick growth
Sentence: So, it cannot concluded that they were endotherms.
Description: A modal auxillary is not usually followed by a verb, past participle
Suggestion: Refer to cannot and concluded
Sentence: First, it is mentioned in the passage that since dinosaur fossils have been found in polar regions and only endotherms can survive low temperaures of polar regions, So they must be endotherms.
Error: temperaures Suggestion: temperatures
Sentence: On the contrary, the lecturer says that this position of legs was for supporting their huge weight and has nothing do with the ablity of running.
Error: ablity Suggestion: ability
flaws:
No. of Grammatical Errors: 4 2
Attribute Value Ideal
Score: 22 in 30
Category: Good Excellent
No. of Grammatical Errors: 4 2
No. of Spelling Errors: 2 2
No. of Sentences: 11 12
No. of Words: 259 250
No. of Characters: 1295 1200
No. of Different Words: 132 150
Fourth Root of Number of Words: 4.012 4.2
Average Word Length: 5 4.6
Word Length SD: 2.348 2.4
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No. of Words greater than 7 chars: 42 40
No. of Words greater than 8 chars: 31 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 23.545 21.0
Sentence Length SD: 8.489 7.5
Use of Discourse Markers (%): 0.636 0.12
Sentence-Text Coherence: 0.418 0.35
Sentence-Para Coherence: 0.637 0.50
Sentence-Sentence Coherence: 0.163 0.07
Number of Paragraphs: 4 4