Animal fossils usually provide very little opportunity to study the actual animal tissues, because in fossils the animals' living tissues have been largely replaced by minerals. Thus, scientists were very excited recently when it appeared that a 70-million-year-old fossil of Tyrannosaurus rex (T. rex), a dinosaur, might still contain remains of the actual tissues of the animal. The discovery was made when researchers deliberately broke open the T. rex’s leg bone, thereby exposing its insides to reveal materials that seem to be remains of blood vessels, red blood cells, and collagen matrix.
First, the breaking of the fossilized leg bone revealed many small branching channels inside, which probably correspond to hollows in the bones where blood vessels were once located. The exciting finding was the presence of a soft, flexible organic substance inside the channels. This soft substance may very well represent the remains of the actual blood vessels of T. rex.
Second, microscopic examination of the various parts of the inner bone revealed the presence of spheres that could be the remains of red blood cells. Tests showed that the spheres contained iron-a material vital to the role of red blood cells in transporting oxygen to tissues. Moreover, the spheres had dark red centers (substances with iron tend to be reddish in color) and were also about the size of red blood cells.
Third, scientists performed a test on the dinosaur leg bone that showed that it contained collagen. Collagen is a fibrous protein that is a main component of living bone tissue, in which it forms a so-called collagen matrix. Collagen (or its chemical derivatives) is exactly the kind of biochemical material that one would expect to find in association with bone tissue.
The lecturer challenges the topic proposed in the reading that T. rex's leg bone contained remains of blood vessels, red blood cells and collagen matrix. And he thinks that these arguments are skeptical.
First, the passage indicates that many small branching channels inside correspond to hollows in the bones where blood vessels were once located. However, the professor argues that these channels might be something elses rather than blood vessels. After dinosaurs were died, there are hollow empty area where bacteria would live inside and they would leave some organic material in them. so the soft substance might be residues left by bacteria colonies.
Second, the article suggests that microscopic examination revealed the presence of spheres could be the remains of red blood cells. But the lecturer points out that these spheres were also found in the same inner bone of other primitive animals which did not have red blood cells. Thus, these spheres might be different origins of iron minerals instead of red blood cells.
Third, the essay supposes that a test showed the leg bone contained collagen. Nevertheless, the professor considers that collagen cannot be found older than 100 years because they cannot last very long. Hence, dinosaur leg bone buried 37 millions years ago contradicts with the facts and the collagen cannot come from the T. rex. Whereas, it could come from human skin, so it may be from researchers who handled the bone.
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Grammar and spelling errors:
Line 3, column 388, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: So
...ld leave some organic material in them. so the soft substance might be residues le...
^^
Transition Words or Phrases used:
also, but, first, hence, however, if, may, nevertheless, second, so, third, thus, whereas
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 11.0 10.4613686534 105% => OK
Auxiliary verbs: 11.0 5.04856512141 218% => Less auxiliary verb wanted.
Conjunction : 5.0 7.30242825607 68% => OK
Relative clauses : 12.0 12.0772626932 99% => OK
Pronoun: 18.0 22.412803532 80% => OK
Preposition: 20.0 30.3222958057 66% => OK
Nominalization: 3.0 5.01324503311 60% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1224.0 1373.03311258 89% => OK
No of words: 237.0 270.72406181 88% => More content wanted.
Chars per words: 5.16455696203 5.08290768461 102% => OK
Fourth root words length: 3.92362132708 4.04702891845 97% => OK
Word Length SD: 2.32052166735 2.5805825403 90% => OK
Unique words: 146.0 145.348785872 100% => OK
Unique words percentage: 0.616033755274 0.540411800872 114% => OK
syllable_count: 361.8 419.366225166 86% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 6.0 8.23620309051 73% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 2.0 1.51434878587 132% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 14.0 13.0662251656 107% => OK
Sentence length: 16.0 21.2450331126 75% => The Avg. Sentence Length is relatively short.
Sentence length SD: 31.088829282 49.2860985944 63% => OK
Chars per sentence: 87.4285714286 110.228320801 79% => OK
Words per sentence: 16.9285714286 21.698381199 78% => OK
Discourse Markers: 6.35714285714 7.06452816374 90% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 4.0 4.45695364238 90% => OK
Sentences with neutral sentiment: 9.0 4.27373068433 211% => Less facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.0538309322833 0.272083759551 20% => The similarity between the topic and the content is low.
Sentence topic coherence: 0.0167232149831 0.0996497079465 17% => Sentence topic similarity is low.
Sentence topic coherence SD: 0.0284159120339 0.0662205650399 43% => Sentences are similar to each other.
Paragraph topic coherence: 0.0284308023429 0.162205337803 18% => Maybe some paragraphs are off the topic.
Paragraph topic coherence SD: 0.021284955916 0.0443174109184 48% => Paragraphs are similar to each other. Some content may get duplicated or it is not exactly right on the topic.
Essay readability:
automated_readability_index: 11.3 13.3589403974 85% => Automated_readability_index is low.
flesch_reading_ease: 63.7 53.8541721854 118% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 8.4 11.0289183223 76% => OK
coleman_liau_index: 12.35 12.2367328918 101% => OK
dale_chall_readability_score: 8.56 8.42419426049 102% => OK
difficult_words: 62.0 63.6247240618 97% => OK
linsear_write_formula: 6.0 10.7273730684 56% => Linsear_write_formula is low.
gunning_fog: 8.4 10.498013245 80% => OK
text_standard: 9.0 11.2008830022 80% => OK
What are above readability scores?
---------------------
It is not exactly right on the topic in the view of e-grader. Maybe there is a wrong essay topic.
Rates: 3.33333333333 out of 100
Scores by essay e-grader: 1.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.