Fossils of the Arm of a Sloth Found in Puerto Rico in 1991, and Dated at 34 Million Years Old, Made it the Earliest known Mammal of the Greater Antilles Island.

Question: Fossils of the arm of a sloth found in Puerto Rico in 1991, and dated at 34 million years old, made it the earliest known mammal of the Greater Antilles island.

1. Sloth found in Puerto Rico in 1991, and dated at 34 million years old, made it the earliest known mammal of
2. Sloth, that they found in Puerto Rica in 1991, has been dated at 34 million years old, thus making it the earliest mammal known on
3. Sloth that was found in Puerto Rico in 1991, was dated at 34 million years old, making it the earliest known mammal of
4. Sloth, found in Puerto Rico in 1991, have been dated at 34 million years old, making the sloth the earliest known mammal on
5. Sloth which, found in Puerto Rico in 1991, was dated at 34 million years old, made the sloth the earliest known mammal of

“Fossils of the arm of a sloth found in Puerto Rico in 1991, and dated at 34 million years old, made it the earliest known mammal of the Greater Antilles island.” is a GMAT sentence correction question. This particular GMAT sentence correction topic has been taken from the book ‘The Official Guide of GMAT Verbal Review, 2nd Edition, 2009’. This question checks Parallelism, Comparison of two elements and Modifiers. GMAT Sentence Correction questions comprise 11-16 questions to be completed within 65 minutes. Each Sentence Correction question contains a sentence with an underlined portion that includes 0-2 errors.

Answer: D

Explanation: The given sentence correction question can be tested by the given-below rules:

1. Subject-verb agreement
2. Pronouns
3. Meanings
4. Verb forms
5. Modifiers
6. Grammatical constructions

Option A: Incorrect
This option is incorrect because it places the vital information of the passage, that is the fossils were dated at 34 million years old, between two commas. Due to this, the statement forms the meaning that the fossils made the sloth the earliest known mammal of the Greater Antilles island. The actual meaning is that the act of dating the fossils at 34 million years old made the sloth the earliest known mammal on the Greater Antilles island. We know that information that is crucial to the core meaning of the sentence should not be placed between commas. So, Option A is incorrect.

Option B: Incorrect
This option is incorrect because it refers to the plural noun ‘fossils’ with the verb ‘has been dated’, which is singular. Also, there is a pronoun error in option B as the pronoun ‘they’ has no logical relevance to the statement. The phrase ‘thus making’ adds up to awkward and unnecessary repetition and can be eliminated without any loss of clarity. Option B is incorrect.

Option C: Incorrect
This option is incorrect because it also refers to the plural noun ‘fossils’ with the singular verb ‘was dated’. Also, the removal of the phrase “was dated at 34 million years old” between the commas leads to an incomplete sentence. Whenever we remove extra information between two commas, it should yield a complete sentence. This is not the case in this passage. So, Option C is incorrect.

Option D: Correct
This option is correct because it refers to the plural noun ‘fossils’ with the plural verb ‘have been dated’. Also, this option correctly places only the extra information between the commas, and the removal of the extra phrase does not contradict the meaning of the passage. So, Option D is correct.

Option E: Incorrect
This option is incorrect because it refers to the plural noun ‘fossils’ with the singular verb ‘was dated’. Further, it incorrectly places the information that is crucial to the main meaning of the passage between two commas. Information that is crucial to the meaning of the sentence should never be placed between commas. Option E is incorrect.

Suggested GMAT critical reasoning questions

• President of the United States: I have Received over 2,000 Letters on this Issue, and the Vast Majority of them Support my Current Position.
• Thelonious Monk, who was a Jazz Pianist and Composer, Produced a Body of Work both Rooted in the Stride-Piano Tradition of Willie (The Lion) Smith and Duke Ellington, Yet in Many ways he Stood Apart from the Mainstream Jazz Repertory.
• TOMMY: That Telephone Always Rings when I am in the Shower and Can’t Hear it.
• Proponents of Artificial Intelligence say they will be able to make Computers that can Understand English and Other Human Languages, Recognize Objects, and Reason as an Expert does—Computers that will be used to Diagnose Equipment Breakdowns, Deciding Whether to Authorize a Loan, or Other Purposes such as these.
• For the First Time Since Influenza Vaccines Became Popular, the Demand for the Vaccine Exceeds the Supply in Our State.
• The Sport of Tennis Develops Muscular Strength, Sharpens Coordination, and Provides Good Cardiovascular Exercise.
• The Increased Concentration of Salt in the Bay, which is the Result of the Recent Drought and High Temperatures, will Cause Many Fish to Die.
• Many Airlines have been Pushing the Federal Government for Assurances of Greater Security in Case of Terrorist Attacks onboard Flights.
• Factory Workers in Beltania are Guaranteed Lifetime Jobs, Bonuses Paid on the Basis of Productivity and Corporate Profits
• Astronomer: Most Stars are Born in Groups of Thousands, Each Star in a Group Forming from the Same Parent Cloud of Gas.
• According to a Study, After a Week of High-Altitude Living, Twenty Men had Slimmed Down.
• In an Experiment, Two Different Types of Recorded Music were Played
• This Museum does not Grant People the Right to Use Images of Items in its Collection in Online Publications
• The Smithtown Theatre, Which Stages Old Plays, has Announced an Expansion that will Double its Capacity Along with its Operating Costs
• In the United States Profits from Sales of Grainco’s Biggest Selling Product, Cornflakes, have Dropped by 30 Percent Over the Last 3 Years
• Exhaust Released from a Combustion Engine is Harmful when Breathed in Significant Quantities.
• Plants are More Efficient at Acquiring Carbon than are Fungi, in the Form of Carbon Dioxide, and Converting it to Energy-Rich Sugars.
• A Person Reading a New Book for Pleasure is Like a Tourist Traveling to a New Place.
• Politician: Tourists Don't Visit our City because of its Reputation of High Crime
• Student: To Improve Business you Should put up a Sign Offering a Special Deal of 12 Croissants for Only $3