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 corresponded 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.
Both the reading passage and lecture discuss whether fossils of Tyrannosaurus rex, a dinosaur, holds actual tissues of the animal till now or not. The former provides three evidence in favor of it, but the later contradicts each of these three points.
First of all, the author of the passage claims that hollows in the fossilizes leg bone might be the evidence of locations of blood vessels, and a soft, flexible organic materials which were inside the channels might be the relics of the real blood vessels of T.rex. However, the lecture contends that the soft organic substances might not be the proof of blood vessels, it could be something else. Bacteria could colonize in the hollows of the bones, and they might destroy the original blood vessels.
Secondly, the text asserts that the dark red spheres were appeared in the inner bone of the fossils while doing microscopic examination, and assumed that it might contain iron which is vital elements of red blood cells to carry oxygen to tissues. In contrast, the listenting counters that other fossils of Tyrannosaurus rex which were found in different locations, showed that this animals had no red cells. Moreover, the reasons of redish looking spheres was that it might have the different origin and contained red minerals.
In third, the reading passage states that there were presence of collagen in the dinosaur leg bone, which was crucial protein substances of living bone tissue. On the other hand, the lecturer mentions that collagen could not lasts longer. As the age of this fossil was 70 million years, it never possible to remain actual collagen such a long time. In addition, collagen might come from the other sources; for example, it might come from th skin of archeologists who handled the fossils.
Grammar and spelling errors:
Line 5, column 378, Rule ID: THIS_NNS[1]
Message: Did you mean 'these'?
Suggestion: these
...und in different locations, showed that this animals had no red cells. Moreover, the...
^^^^
Line 7, column 226, Rule ID: DID_BASEFORM[1]
Message: The verb 'could' requires the base form of the verb: 'last'
Suggestion: last
...cturer mentions that collagen could not lasts longer. As the age of this fossil was 7...
^^^^^
Transition Words or Phrases used:
but, first, however, if, look, moreover, second, secondly, so, third, while, for example, in addition, in contrast, first of all, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 12.0 10.4613686534 115% => OK
Auxiliary verbs: 11.0 5.04856512141 218% => Less auxiliary verb wanted.
Conjunction : 7.0 7.30242825607 96% => OK
Relative clauses : 14.0 12.0772626932 116% => OK
Pronoun: 19.0 22.412803532 85% => OK
Preposition: 37.0 30.3222958057 122% => OK
Nominalization: 5.0 5.01324503311 100% => OK
Performance on vocabulary words:
No of characters: 1485.0 1373.03311258 108% => OK
No of words: 297.0 270.72406181 110% => OK
Chars per words: 5.0 5.08290768461 98% => OK
Fourth root words length: 4.15134772569 4.04702891845 103% => OK
Word Length SD: 2.45190446938 2.5805825403 95% => OK
Unique words: 165.0 145.348785872 114% => OK
Unique words percentage: 0.555555555556 0.540411800872 103% => OK
syllable_count: 441.0 419.366225166 105% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 3.0 3.25607064018 92% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 4.0 1.51434878587 264% => Less conjunction wanted as sentence beginning.
Preposition: 4.0 2.5761589404 155% => OK
Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 24.0 21.2450331126 113% => OK
Sentence length SD: 54.1194666148 49.2860985944 110% => OK
Chars per sentence: 123.75 110.228320801 112% => OK
Words per sentence: 24.75 21.698381199 114% => OK
Discourse Markers: 12.25 7.06452816374 173% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 2.0 4.19205298013 48% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 3.0 4.45695364238 67% => OK
Sentences with neutral sentiment: 6.0 4.27373068433 140% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.131035957989 0.272083759551 48% => OK
Sentence topic coherence: 0.0485541849266 0.0996497079465 49% => OK
Sentence topic coherence SD: 0.0550634591553 0.0662205650399 83% => OK
Paragraph topic coherence: 0.0835516500512 0.162205337803 52% => OK
Paragraph topic coherence SD: 0.0454172189463 0.0443174109184 102% => OK
Essay readability:
automated_readability_index: 14.5 13.3589403974 109% => OK
flesch_reading_ease: 55.58 53.8541721854 103% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 11.5 11.0289183223 104% => OK
coleman_liau_index: 12.02 12.2367328918 98% => OK
dale_chall_readability_score: 8.76 8.42419426049 104% => OK
difficult_words: 74.0 63.6247240618 116% => OK
linsear_write_formula: 13.0 10.7273730684 121% => OK
gunning_fog: 11.6 10.498013245 110% => OK
text_standard: 12.0 11.2008830022 107% => OK
What are above readability scores?
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Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 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.