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 reading claims that a 70-million-year-old fossil of T. rex might still contain remains of the actual tissues of the animal. However, the lecturer finds all the ideas dubious and presents some evidence to refute them all.
First, the reading asserts that the presence of a soft, flexible organic substance inside the channels is a sign of the remains the actual blood vessels of T. rex. In contrast, the professor underlines the fact that it does not necessarily represent this idea and may be something else. They might be organic materials remained from the colony of bacteria which colonized in the hollows of the fossil.
Furthermore, the reading passage argues that the spheres contained iron and their size and color are similar to those of red blood cells. On the contrary, the speaker dismisses this issue due to the fact that the identical spheres were found in other fossils in the area which belongs to animals which did not have any red blood cells when they were alive.
Finally, the author claims that the collagen found in the fossil is exactly the kind of biochemical material that one would expect to find in association with bone tissue. Conversely, the lecturer asserts that collagen cannot last more than 1000 years while the fossil belongs to an earlier era. This collagen may come from another recent source. It might belong to the skin of a researcher, who was holding the bone of a fossil.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2018-11-28 | Mohammed AlKhars | 3 | view |
| 2018-11-28 | Mohammed AlKhars | 3 | view |
| 2018-11-28 | Mohammed AlKhars | 3 | view |
| 2018-10-19 | prem123 | 76 | view |
| 2018-10-18 | Munaim Hossain | 90 | view |
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Transition Words or Phrases used:
conversely, finally, first, furthermore, however, may, so, still, while, in contrast, kind of, on the contrary
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 8.0 10.4613686534 76% => OK
Auxiliary verbs: 7.0 5.04856512141 139% => OK
Conjunction : 4.0 7.30242825607 55% => More conjunction wanted.
Relative clauses : 13.0 12.0772626932 108% => OK
Pronoun: 18.0 22.412803532 80% => OK
Preposition: 30.0 30.3222958057 99% => OK
Nominalization: 4.0 5.01324503311 80% => OK
Performance on vocabulary words:
No of characters: 1186.0 1373.03311258 86% => OK
No of words: 242.0 270.72406181 89% => More content wanted.
Chars per words: 4.90082644628 5.08290768461 96% => OK
Fourth root words length: 3.94415379849 4.04702891845 97% => OK
Word Length SD: 2.51937373978 2.5805825403 98% => OK
Unique words: 141.0 145.348785872 97% => OK
Unique words percentage: 0.582644628099 0.540411800872 108% => OK
syllable_count: 357.3 419.366225166 85% => 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: 8.0 8.23620309051 97% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 20.0 21.2450331126 94% => OK
Sentence length SD: 47.6977608373 49.2860985944 97% => OK
Chars per sentence: 98.8333333333 110.228320801 90% => OK
Words per sentence: 20.1666666667 21.698381199 93% => OK
Discourse Markers: 9.16666666667 7.06452816374 130% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 4.19205298013 0% => OK
Sentences with positive sentiment : 2.0 4.33554083885 46% => More positive sentences wanted.
Sentences with negative sentiment : 2.0 4.45695364238 45% => More negative sentences wanted.
Sentences with neutral sentiment: 8.0 4.27373068433 187% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.132862705566 0.272083759551 49% => OK
Sentence topic coherence: 0.0444886224432 0.0996497079465 45% => OK
Sentence topic coherence SD: 0.041475833026 0.0662205650399 63% => OK
Paragraph topic coherence: 0.0741516754793 0.162205337803 46% => OK
Paragraph topic coherence SD: 0.0270549426462 0.0443174109184 61% => OK
Essay readability:
automated_readability_index: 11.7 13.3589403974 88% => Automated_readability_index is low.
flesch_reading_ease: 59.64 53.8541721854 111% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.9 11.0289183223 90% => OK
coleman_liau_index: 11.14 12.2367328918 91% => OK
dale_chall_readability_score: 8.48 8.42419426049 101% => OK
difficult_words: 59.0 63.6247240618 93% => OK
linsear_write_formula: 8.0 10.7273730684 75% => OK
gunning_fog: 10.0 10.498013245 95% => OK
text_standard: 10.0 11.2008830022 89% => OK
What are above readability scores?
---------------------
Rates: 86.6666666667 out of 100
Scores by essay e-grader: 26.0 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.