Dr. Mary Leakey found teeth and jawbones in Tanzania dating to 3.75

OFFICIAL EXPLANATION



• HIGHLIGHTS

• Although the coupling is not common on the GMAT, a past participle and a present participle can be parallel.
Both found and dating to are participial adjectives. They modify the nouns teeth and jawbones. See the notes below.

• "Date to" is idiomatic. HERE is an official question in which "date to" is used.

THE PROMPT


THE OPTIONS

• a present participle (verbING) without a comma (dating) modifies the immediately preceding noun Tanzania and produces nonsense. Tanzania is not dated to 3.75 million years ago.
• they might be ambiguous. Logically I think it can mean only "teeth and jawbones," but the sentence would be better without any hint of ambiguity.
Eliminate A


• dating to 3.75 million years ago is a noun modifier of "human fossils" and should be placed as closely as possible to the noun
• we might be able to argue that "dating to 3.75 million years ago" modifies the whole previous clause
-- "dating to 3.75 millions years ago" might qualify as "extra information" about the clause, but that logic is a stretch. "Dating to XXX" refers to fossils and does not tell us anything about "fossils were found by Dr. Mary Leakey.
-- although GMAC frequent uses present participles (verbINGs) as clause modifiers, remember that participles are often adjectives.
• passive voice? Passive voice is often correct on the GMAT.
• the sentence is more descriptive with "teeth and jawbones" included; three other options have that detail.
KEEP, but look for a better option


• This sentence is clear: subject + two adjectives (found . . and dating . . .), a linking verb, and a subject complement
-- common linking verbs are is, become, and seem. These verbs connect the subject to additional information about the subject.
-- the thing on the other side of the linking verb is called a subject complement,
• present and past participles found and dating are parallel as a matter of logic. Both are adjectives that describe teeth and jawbones. See below.
• the active voice probably does not make that much difference, but it's a slight bonus

• this sentence is hard to read. And is a parallelism marker.
-- The verbs date and are are parallel, but the verb date follows the past participle, found, (are you dizzy yet?) an arrangement that is not as clear as that in C
• In Tanzania suggests that the fossils are the oldest in Tanzania. At the least the issue is not clear.
Introductory prepositional phrases are very versatile. They do not have to modify the subject of the subsequent clause.
-- Compare:
In Tibet and Nepal, Mt. Everest measures almost 30,000 feet and is the tallest mountain. (Everest is the tallest mountain in Tibet and Nepal)
Mt. Everest in Tibet and Nepal measures almost 30,000 feet and is the tallest mountain. (Everest is the the tallest mountain in the world)
Eliminate D

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-- The sentence is scrambled. Compared to (C), option E is not as clear
-- The inverted structure (verb → subject) is cumbersome; again, compared to (C), there is no reason to put the verb "are" before the subject "oldest fossils."
-- The introductory descriptors are both adjectives but are a little strange compared to (C): located in Tanzania and dating to 3.75 million years ago would be better.
-- "teeth and jawbones" are not present; the sentence would be more descriptive if it included them
-- Grammatical but not as effective or clear as C
Eliminate E

Option B v. Option C? Option C wins.
Option C places dating close to its noun, is not in passive voice, and includes "teeth and jawbones."

The answer is C

• NOTES

Found and dating are parallel
-- In C, two qualities describe the compound subject teeth and jawbones: found in Tanzania and dating to 3.75 million years ago
-- See this SC Butler question, here, from just a few days ago, in which [SPOILER ALERT] I link to an official question. If you click the spoiler, you know the answer to an official question. That question is


As I wrote in my other post, parallelism is grounded in logic. If logic requires different participles, grammar adapts.

Although the pairing of past and present participles is not common on the GMAT, that pairing is also allowed—as it should be.
In good prose, that pairing is fairly common.

COMMENTS

exliontamer , welcome to SC Butler.

This question is hard. Errors are not "slam dunk" and obvious.
We have one job: find the four worst answers, make sure the remaining answer is grammatical, mark that answer, and move on.
We are not looking for the best possible or perfect option. We are looking for the best option of five.

In this case, that option is straightforward and well-written, but sometimes "best of five" will seem to be a not-great sentence.


Everyone who took this on and explained gets kudos, even if a person relied on a bad assumption and did not reach the right conclusion.
I have watched critical reasoning skills improve markedly in the last few months.
Nice work.