The fossil remains of the first flying vertebrates, the pterosaurs

Question

The fossil remains of the first flying vertebrates, the pterosaurs, have intrigued paleontologists for more than two centuries. How such large creatures, which weighed in some cases as much as a piloted hang-glider and had wingspans from 8 to 12 meters, solved the problems of powered flight, and exactly what these creatures were—reptiles or birds—are among the questions scientists have puzzled over.

Overall: How pterosaur flyed with such large wingspan is a puzzle for paleontologists.

Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skulls, pelvises, and hind feet are reptilian. The anatomy of their wings suggests that they did not evolve into the class of birds. In pterosaurs a greatly elongated fourth finger of each forelimb supported a wing-like membrane. The other fingers were short and reptilian, with sharp claws. In birds the second finger is the principal strut of the wing, which consists primarily of feathers. If the pterosaurs walked on all fours, the three short fingers may have been employed for grasping. When a pterosaur walked or remained stationary, the fourth finger, and with it the wing, could only turn upward in an extended inverted V-shape along each side of the animal’s body.

Overall: Most probably they are reptiles.

The pterosaurs resembled both birds and bats in their overall structure and proportions. This is not surprising because the design of any flying vertebrate is subject to aerodynamic constraints. Both the pterosaurs and the birds have hollow bones, a feature that represents a savings in weight. In the birds, however, these bones are reinforced more massively by internal struts.
Overall: They are similar to both birds and baths as they have hollow bones.

Although scales typically cover reptiles, the pterosaurs probably had hairy coats. T. H. Huxley reasoned that flying vertebrates must have been warm-blooded because flying implies a high rate of metabolism, which in turn implies a high internal temperature. Huxley speculated that a coat of hair would insulate against loss of body heat and might streamline the body to reduce drag in flight. The recent discovery of a pterosaur specimen covered in long, dense, and relatively thick hairlike fossil material was the first clear evidence that his reasoning was correct.
Overall: They have hairy coats because flying need high rate of metabolism.

Efforts to explain how the pterosaurs became airborne have led to suggestions that they launched themselves by jumping from cliffs, by dropping from trees, or even by rising into light winds from the crests of waves. Each hypothesis has its difficulties. The first wrongly assumes that the pterosaurs’ hind feet resembled a bat’s and could serve as hooks by which the animal could hang in preparation for flight. The second hypothesis seems unlikely because large pterosaurs could not have landed in trees without damaging their wings. The third calls for high waves to channel updrafts. The wind that made such waves however, might have been too strong for the pterosaurs to control their flight once airborne.
Overall: Multiple suggestion how they become airborne but all are rejected.

1. It can be inferred from the passage that scientists now generally agree that the

(A) enormous wingspan of the pterosaurs enabled them to fly great distances

(B) structure of the skeleton of the pterosaurs suggests a close evolutionary relationship to bats

(C) fossil remains of the pterosaurs reveal how they solved the problem of powered flight

(D) pterosaurs were reptiles
Perhaps the least controversial assertion about the pterosaurs is that they were reptiles.
(E) pterosaurs walked on all fours

2. The author views the idea that the pterosaurs became airborne by rising into light winds created by waves as

(A) revolutionary
(B) unlikely
The third calls for high waves to channel updrafts. The wind that made such waves however, might have been too strong for the pterosaurs to control their flight once airborne.
(C) unassailable
(D) probable
(E) outdated

3. According to the passage, the skeleton of a pterosaur can be distinguished from that of a bird by the

(A) size of its wingspan
(B) presence of hollow spaces in its bones
(C) anatomic origin of its wing strut
The other fingers were short and reptilian, with sharp claws. In birds the second finger is the principal strut of the wing, which consists primarily of feathers.
(D) presence of hooklike projections on its hind feet
(E) location of the shoulder joint joining the wing to its body

4. The ideas attributed to T. H. Huxley in the passage suggest that he would most likely agree with which of the following statements?

(A) An animal’s brain size has little bearing on its ability to master complex behaviors.

(B) An animal’s appearance is often influenced by environmental requirements and physical capabilities.
T. H. Huxley reasoned that flying vertebrates must have been warm-blooded because flying implies a high rate of metabolism, which in turn implies a high internal temperature. Huxley speculated that a coat of hair would insulate against loss of body heat and might streamline the body to reduce drag in flight.

(C) Animals within a given family group are unlikely to change their appearance dramatically over a period of time.

(D) The origin of flight in vertebrates was an accidental development rather than the outcome of specialization or adaptation.

(E) The pterosaurs should be classified as birds, not reptiles

5. It can be inferred from the passage that which of the following is characteristic of the pterosaurs?

(A) They were unable to fold their wings when not in use.
When a pterosaur walked or remained stationary, the fourth finger, and with it the wing, could only turn upward in an extended inverted V-shape along each side of the animal’s body.

(B) They hung upside down from branches as bats do before flight.

(C) They flew in order to capture prey.

(D) They were an early stage in the evolution of the birds.

(E) They lived primarily in a forest-like habitat.

6. Which of the following best describes the organization of the last paragraph of the passage?

(A) New evidence is introduced to support a traditional point of view.

(B) Three explanations for a phenomenon are presented, and each is disputed by means of specific information.
correct

(C) Three hypotheses are outlined, and evidence supporting each is given.

(D) Recent discoveries are described, and their implications for future study are projected.

(E) A summary of the material in the preceding paragraphs is presented, and conclusions are drawn.

7. It can be inferred from the passage that some scientists believe that pterosaurs

(A) lived near large bodies of water
Mentioned in passage: The third calls for high waves to channel updrafts.
(B) had sharp teeth for tearing food

(C) were attacked and eaten by larger reptiles

(D) had longer tails than many birds

(E) consumed twice their weight daily to maintain their body temperature

h2polo · Accepted Answer

Explaining as to why is 7th question is A:

We can assume that the pterosaurs lived near large bodies of water, because one of the hypothesis for how the pterosaurs flew was that they somehow took advantage of "high waves to channel updrafts". Why would the scientists think that if they didn't think pterosaurs lived by water?

Hope it helps. :-D

GMATNinja · Answer

There is only one place in the entire passage where the author mentions what pterosaurs do  when they're not flying  (i.e, when their wings are not in use):

When a pterosaur  walked or remained stationary , the fourth finger, and with it the wing, could only turn upward in an extended inverted V-shape along each side of the animal’s body.

If the pterosaur was walking or was stationary, then it was definitely not flying. So this sentence tells us that the wing, when not in use, could  only  turn  upward  in an  extended  inverted V-shape along each side of the animal's body. That does not sound like a folded wing, as we'd expect to see on a pigeon walking down along the street.

Even if the whole sentence is a knot of words, there are enough clear word choices here to imply that pterosaurs' wings were stuck in an extended position when they weren't being used for flight. Let's keep (A) and see if it's easier to eliminate the other choices.

This is the opposite of what the author writes in the final paragraph:

"The first  wrongly assumes that  the pterosaurs’ hind feet resembled a bat’s and could serve as hooks by which the animal could hang in preparation for flight."

So we'll eliminate (B).

There isn't a single moment in this passage where the author describes how pterosaurs captured their prey, or even hunted their prey, or even ate anything. Eliminate (C).

As with choice (B), this choice is directly contradicted by the passage, in the second paragraph:

"The anatomy of their wings suggests that they did  not  evolve into the class of birds."

Eliminate (D).

As with choice (C), we have no indication of the pterosaurs' habitat in this passage. The final paragraph describes a few settings -- cliffs, trees, and the ocean -- where pterosaurs might have interacted with the environment to become airborne. However, the author brings up these settings as parts of hypotheses that have "difficulties." This reference does not give us enough information to infer that pterosaurs  lived primarily  in a  forest-like habitat , so we'll eliminate (E), too.

(A) remains the only answer choice that is supported by the passage, and that's why we keep it and move on.

MartyTargetTestPrep · Answer

Hi givinggmat.

You ask a great question.

GMAT Ninja provides an answer to your question a few posts above yours.

At the same time, the truth is that question 5 is a little weak. Nowhere in the passage is it truly made clear that they could not fold their wings. The only way to get question 5 correct is to eliminate the four choices that are clearly incorrect and then decide that the following sentence, which seems to be focused on a finger, could be interpreted as indicating that they cannot fold their wings.

When a pterosaur walked or remained stationary, the fourth finger, and with it the wing, could only turn upward in an extended inverted V-shape along each side of the animal’s body.

The truth is that even some official questions are a little flawed, and this question seems to be such a question.

AdityaHongunti · Answer

Can someone please explain question 5? Where in the passage is it given that these animals were not able to fold their wings when not in use ?

BodhiChatterjee · Answer

Can you please provide an explanation for #7?

GMATNinja · Answer

Question 7 
 
 Brian123  explained (A) for question 7 in  this post , but see below for our two cents in case it helps.

In paragraph 5, the author presents the hypothesis that pterosaurs took flight by “ rising…from crests of waves."  As far as I know, the only places that have waves are large bodies of water. Therefore, some scientists must think that pterosaurs lived near  large bodies of water . Let’s hang on to (A).

The passage doesn’t mention pterosaurs' teeth. (B) is out.

Again, not mentioned in the passage. (C) is out.

In paragraphs 2 and 3, pterosaurs are compared to birds. But tails are not mentioned. (D) is out.

Nope – we don’t learn anything about what pterosaurs ate. (E) is out.

So we’re left with (A).

I hope that helps!

gonayfrank · Answer

Please explain me question 2. My choice is D) Probable Reason : "The wind that made such waves however, might have been too strong for the pterosaurs to control their flight once airborne." Here from the words of the passage we can infer that the author is not completely denying the possibility. The use of "might" makes option D a favorable choice for me.

GMATNinja · Answer

Question 2 
 
By using the word "might," the author doesn't 100% rule out the possibility that pterosaurs became airborne by rising into light winds created by waves.

However, that's very different than saying that this hypothesis is  "probable."  "Probable" would indicate that the author thinks the hypothesis is  likely correct . That's just not the case -- the author says that "each" hypothesis has its difficulties, and particularly mentions the strength of the wind as the problem with the wind wave hypothesis.

"Unlikely," as stated in (B), is a much better fit. Again, the author doesn't 100% rule out the hypothesis, but he/she does present some evidence against it.

(B) is the correct answer for question 2.

I hope that helps!

iamthebest8055 · Answer

how can we infer that pterosaures lived near water bodies

MartyTargetTestPrep · Answer

Here's what question 7 and its correct answer say exactly.

7. It can be inferred from the passage that some scientists believe that pterosaurs

(A) lived near large bodies of water

We can infer what choice (A) says from what the passage says in the fifth paragraph.

Efforts to explain how the pterosaurs became airborne have led to suggestions that they launched themselves ... by rising into light winds from the crests of waves. ... The third calls for high waves to channel updrafts. The wind that made such waves however, might have been too strong for the pterosaurs to control their flight once airborne.

If some scientists have suggested that pterosaurs launched themselves from "high waves," then since such waves would only exist in large bodies of water, a reasonable conclusion is that "some scientists believe that pterosaurs lived near large bodies of water."

woohoo921 · Answer

KarishmaB

If I am counting correctly based on the format of this paragraph, it seems that there are about 50 lines to this passage? I am curious to learn more about your timing strategy for RC.

Do you allocate e.g., 3 minutes to passages that have greater than let's say 45 lines and 2 minutes to passages that have about 30 lines... assuming in both cases you spend on average 2 minutes per question?

Overall, I would be so appreciative for your point of view on timing for RC (e.g., or do you spend more on the passage e.g., 4 minutes and less on the questions e.g., 1 minute per question)?

KarishmaB · Answer

In a timed test such as this one, the idea would be to spend as little time as possible on each question (of course!). Your time allocation will vary a lot depending on the subject of the passage (your comfort in it), the length of the passage, the difficulty level of the passage, your reading speed and your time management till that point in the section. 
There are no ideal time allocation figures - I would suggest test-takers to read the passage twice. First read to understand the subject being discussed and the second read to understand exactly what the passage tells us about that subject. This needs to be done in as little time as possible but properly so it varies widely even from one passage to another for the same test taker. 
Once that is done, hopefully, the universal questions would be answered without going back to the passage. The specific detail questions would require going back to the part of the passage where that particular topic was discussed. I would suggest targeting, on average, about a minute per question now.

woohoo921 · Answer

KarishmaB As always, you are so lovely and helpful. Do you have any guidelines for how long different passage lengths should take to reread (or for your strategy of rereading twice)? E.g., 3 minutes for 50 lines, 2 minutes for 30 lines? Do you take notes while reading? Thank you again

singhaz · Answer

The fossil remains of the first flying vertebrates, the pterosaurs, have intrigued paleontologists for more than two centuries. How such large creatures, which weighed in some cases as much as a piloted hang-glider and had wingspans from 8 to 12 meters, solved the problems of powered flight, and exactly what these creatures were—reptiles or birds—are among the questions scientists have puzzled over.

Overall: How pterosaur flyed with such large wingspan is a puzzle for paleontologists.

Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skulls, pelvises, and hind feet are reptilian. The anatomy of their wings suggests that they did not evolve into the class of birds. In pterosaurs a greatly elongated fourth finger of each forelimb supported a wing-like membrane. The other fingers were short and reptilian, with sharp claws. In birds the second finger is the principal strut of the wing, which consists primarily of feathers. If the pterosaurs walked on all fours, the three short fingers may have been employed for grasping. When a pterosaur walked or remained stationary, the fourth finger, and with it the wing, could only turn upward in an extended inverted V-shape along each side of the animal’s body.

Overall: Most probably they are reptiles.

The pterosaurs resembled both birds and bats in their overall structure and proportions. This is not surprising because the design of any flying vertebrate is subject to aerodynamic constraints. Both the pterosaurs and the birds have hollow bones, a feature that represents a savings in weight. In the birds, however, these bones are reinforced more massively by internal struts.
Overall: They are similar to both birds and baths as they have hollow bones.

Although scales typically cover reptiles, the pterosaurs probably had hairy coats. T. H. Huxley reasoned that flying vertebrates must have been warm-blooded because flying implies a high rate of metabolism, which in turn implies a high internal temperature. Huxley speculated that a coat of hair would insulate against loss of body heat and might streamline the body to reduce drag in flight. The recent discovery of a pterosaur specimen covered in long, dense, and relatively thick hairlike fossil material was the first clear evidence that his reasoning was correct.
 Overall: They have hairy coats because flying need high rate of metabolism.

Efforts to explain how the pterosaurs became airborne have led to suggestions that they launched themselves by jumping from cliffs, by dropping from trees, or even by rising into light winds from the crests of waves. Each hypothesis has its difficulties. The first wrongly assumes that the pterosaurs’ hind feet resembled a bat’s and could serve as hooks by which the animal could hang in preparation for flight. The second hypothesis seems unlikely because large pterosaurs could not have landed in trees without damaging their wings. The third calls for high waves to channel updrafts. The wind that made such waves however, might have been too strong for the pterosaurs to control their flight once airborne.
 Overall: Multiple suggestion how they become airborne but all are rejected.

1. It can be inferred from the passage that scientists now generally agree that the

(A) enormous wingspan of the pterosaurs enabled them to fly great distances

(B) structure of the skeleton of the pterosaurs suggests a close evolutionary relationship to bats

(C) fossil remains of the pterosaurs reveal how they solved the problem of powered flight

(D) pterosaurs were reptiles
Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. 
(E) pterosaurs walked on all fours

2. The author views the idea that the pterosaurs became airborne by rising into light winds created by waves as

(A) revolutionary
 (B) unlikely
The third calls for high waves to channel updrafts. The wind that made such waves however, might have been too strong for the pterosaurs to control their flight once airborne. 
(C) unassailable
(D) probable
(E) outdated

3. According to the passage, the skeleton of a pterosaur can be distinguished from that of a bird by the

(A) size of its wingspan
(B) presence of hollow spaces in its bones
 (C) anatomic origin of its wing strut
The other fingers were short and reptilian, with sharp claws. In birds the second finger is the principal strut of the wing, which consists primarily of feathers. 
(D) presence of hooklike projections on its hind feet
(E) location of the shoulder joint joining the wing to its body

4. The ideas attributed to T. H. Huxley in the passage suggest that he would most likely agree with which of the following statements?

(A) An animal’s brain size has little bearing on its ability to master complex behaviors.

(B) An animal’s appearance is often influenced by environmental requirements and physical capabilities.
T. H. Huxley reasoned that flying vertebrates must have been warm-blooded because flying implies a high rate of metabolism, which in turn implies a high internal temperature. Huxley speculated that a coat of hair would insulate against loss of body heat and might streamline the body to reduce drag in flight.

(C) Animals within a given family group are unlikely to change their appearance dramatically over a period of time.

(D) The origin of flight in vertebrates was an accidental development rather than the outcome of specialization or adaptation.

(E) The pterosaurs should be classified as birds, not reptiles

5. It can be inferred from the passage that which of the following is characteristic of the pterosaurs?

(A) They were unable to fold their wings when not in use.
When a pterosaur walked or remained stationary, the fourth finger, and with it the wing, could only turn upward in an extended inverted V-shape along each side of the animal’s body.

(B) They hung upside down from branches as bats do before flight.

(C) They flew in order to capture prey.

(D) They were an early stage in the evolution of the birds.

(E) They lived primarily in a forest-like habitat.

6. Which of the following best describes the organization of the last paragraph of the passage?

(A) New evidence is introduced to support a traditional point of view.

(B) Three explanations for a phenomenon are presented, and each is disputed by means of specific information.
correct

(C) Three hypotheses are outlined, and evidence supporting each is given.

(D) Recent discoveries are described, and their implications for future study are projected.

(E) A summary of the material in the preceding paragraphs is presented, and conclusions are drawn.

7. It can be inferred from the passage that some scientists believe that pterosaurs

(A) lived near large bodies of water
Mentioned in passage: The third calls for high waves to channel updrafts. 
(B) had sharp teeth for tearing food

(C) were attacked and eaten by larger reptiles

(D) had longer tails than many birds

(E) consumed twice their weight daily to maintain their body temperature

KarishmaB · Answer

Assuming a test taker needs 1 - 1.5 mins for an SC question and 2.5 - 3 mins for a CR question, and assuming an RC passage has 3-4 questions and each questions needs 1 min each, you would have about 3 mins for the two reads of the passage. The actual time will vary a lot. Number of lines etc is just one aspect of the time required so you cannot decide based on the length. Anyway, you won't have the time to get into those kind of calculations.

GMATNinja · Answer

Question 7 
 
Here's (E):
 
This is specific information that just can't be inferred from the passage. All we get is a mention of high metabolism, and there's just no way to jump from that to "consumed twice their weight daily." That's why we can't infer that some scientists believe the information in (E).

I hope that helps!

achloes · Answer

MartyTargetTestPrep   GMATNinja   KarishmaB

I picked "probable" because the author says that the animal could have become airborne by rising into light winds created by waves, however, it wasn't ideal as the wind might have been too strong.

In other words, becoming airborne was probable but the winds were not favorable to the animal.

What am I missing?

KarishmaB · Answer

Note that the question asks us the author's views.

The author views the idea  that the pterosaurs became airborne by rising into light winds created by waves  as ...

This is what the author says:

Efforts to explain how the pterosaurs became airborne have led to suggestions that they launched themselves by jumping from cliffs, by dropping from trees, or even by rising into light winds from the crests of waves.  Each hypothesis has its difficulties.

and then he goes on to explain the difficulty with each hypothesis:
..
..
 The third calls for high waves to channel updrafts. The wind that made such waves however, might have been too strong for the pterosaurs to control their flight once airborne.

So as per the author, each hypothesis has concerns and hence each is improbable. The issue with the third one is that the wind might have been too strong to control their flight. Hence, he thinks that this hypothesis is unlikely.

Answer (B)

dhruvadityajain · Answer

1. It can be inferred from the passage that scientists now generally agree that the

(A) enormous wingspan of the pterosaurs enabled them to fly great distances

From the passage, we know that pterosaurs can fly (It is mentioned in the first para that scientists are intrigued by how pterosaurs solve the problem of powered flights ). Still, nowhere in the passage is it mentioned that pterosaurs can fly to a great distance.

(B) structure of the skeleton of the pterosaurs suggests a close evolutionary relationship to bats
In the last para (it wrongly assumes that the pterosaurs’ hind feet resembled a bat’s and could serve as hooks by which the animal could hang in preparation for flight.), we can infer that pterosaurs are in close relationship to bat

In the third part (The pterosaurs resembled both birds and bats in their overall structure and proportions.), pterosaurs just resembled birds and bats, not in a close relationship.

(C) fossil remains of the pterosaurs reveal how they solved the problem of powered flight
Nowhere in para is it mentioned that pterosaurs solved the problem of powered flights. In the last part, the author has rejected all the hypotheses of how pterosaurs become airborne.

(D) pterosaurs were reptiles
In the second part, it is mentioned that pterosaurs are reptiles (Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. )

(E) pterosaurs walked on all fours
From the passage, we know that pterosaurs has four fingers, but the fourth finger is attached with wings to support the wing-like membrane, and the fourth finger can only turn upward in an extended inverted V-shape along each side of the animal’s body. I will suggest you see the fossil of pterosaurs on Google for a clear understanding.

The fossil remains of the first flying vertebrates, the pterosaurs

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GMAT Reading Comprehension (RC) Questions

The fossil remains of the first flying vertebrates, the pterosaurs

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