Research teams excavating in Montana have discovered fossil specimens that seem to constitute a previously unidentified early mammalian species. Datin...
GMAT Information and Ideas : (Ideas) Questions
Research teams excavating in Montana have discovered fossil specimens that seem to constitute a previously unidentified early mammalian species. Dating through radiometric methods shows these remains to be roughly 65 million years in age, corresponding to the final phase of the Cretaceous era. The project's principal investigator, Dr. Sarah Chen, believes this find may offer fresh understanding of mammalian evolutionary diversification after the demise of non-avian dinosaurs.
Which choice best states the main topic of the text?
An early mammalian fossil discovery in Montana
Methods for determining prehistoric specimen ages
The demise of non-avian dinosaurs
Dr. Sarah Chen's investigative approaches
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Research teams excavating in Montana have discovered fossil specimens that seem to constitute a previously unidentified early mammalian species." |
|
| "Dating through radiometric methods shows these remains to be roughly 65 million years in age, corresponding to the final phase of the Cretaceous era." |
|
| "The project's principal investigator, Dr. Sarah Chen, believes this find may offer fresh understanding of mammalian evolutionary diversification after the demise of non-avian dinosaurs." |
|
Part B: Provide Passage Architecture & Core Elements
Main Point: Research teams in Montana have discovered fossils of a previously unknown early mammalian species that may provide new insights into mammalian evolution.
Argument Flow: The passage presents a straightforward announcement of a scientific discovery. It opens with the central finding (new mammalian fossils), provides crucial contextual information about their age and geological period, then concludes with expert interpretation about why this discovery matters for our understanding of mammalian evolution.
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- The passage is fundamentally about a fossil discovery - specifically, new mammalian fossils found in Montana
- While the text mentions dating methods, the Cretaceous period, dinosaur extinction, and Dr. Chen's perspective, these are all supporting details that provide context for the main event: the discovery itself
- The right answer should focus on the fossil discovery as the central topic, probably mentioning that it's mammalian fossils and likely including the Montana location since that's how the passage opens
An early mammalian fossil discovery in Montana
✓ Correct
- Directly captures the main focus - the fossil discovery
- Includes the key details: early mammalian species and Montana location
- Matches our prethinking about what the passage is primarily discussing
Methods for determining prehistoric specimen ages
✗ Incorrect
- Focuses on dating methods, which are mentioned briefly but aren't the main topic
- This trap targets students who focus on the radiometric dating detail and think the passage is about scientific methods rather than the discovery itself
The demise of non-avian dinosaurs
✗ Incorrect
- Dinosaur extinction is mentioned only as context for understanding the significance
- This is background information, not the main topic
- This trap targets students who get distracted by dramatic details like "demise of non-avian dinosaurs" even when they're just providing context
Dr. Sarah Chen's investigative approaches
✗ Incorrect
- Dr. Chen is mentioned as the investigator, but her approaches aren't discussed
- The passage focuses on the discovery and its significance, not her methods
- Too narrow and misses the actual focus of the passage