Why the Earthviewer Mass Extinctions Answer Key exists
You will find this when you are grading or self-checking quiz results from the Earthviewer simulation. The answer key is not a separate document you download. It is embedded in the simulation data itself, which is why so many people waste an hour looking for a file that does not exist in any conventional form. I worked through this three times before I figured out the actual workflow. The first attempt took me forty-five minutes because I was looking for a PDF that the platform never generates. The second time I found the data export feature, which outputs CSV rows that contain the correct biomes, species, and time periods. The third time I stopped trying to match answers manually and just pulled the ground truth directly from the simulation state.
Getting the Earthviewer Mass Extinctions Answer Key
Open the simulation, complete the mass extinction event you are being tested on, then click the export button in the top right corner. This gives you a JSON file. The file contains arrays labeled expected_output and correct_answers. Those arrays are your answer key. They contain the exact species that should be present, the correct extinction percentages, and the timeline values the grading script uses. Do not try to reverse-engineer the answers by watching the simulation replay. The replay shows the visual sequence, but it does not expose the numerical thresholds the grader applies. You will get close on most events, but the Permian-Triassic boundary event uses a different extinction threshold than the Cretaceous-Palatine one, and the simulation does not make that distinction visible in the animation. Once you have the JSON, filter for the event you need. The file is usually two or three megabytes because it stores every species in the simulation, not just the ones relevant to the extinction. My workaround for trimming it down was to grep for the specific event name and pipe it through jq with a filter on the expected_output array. That reduced the relevant section from about 1.8 megabytes to roughly 40 kilobytes, which is fast enough to open in any text editor without lagging the machine.
Some people prefer the CSV version instead. The CSV is easier to read but lacks the nested structure of the JSON. You lose the species hierarchy, which matters if you need to distinguish between marine and terrestrial extinctions in the same event. I use the JSON unless the class is using a spreadsheet-based grading system, in which case I export the CSV and map the columns manually. There is no standalone download link for the answer key because the platform does not host one. If you see a site claiming to offer a direct PDF download, it is either outdated or scraping the JSON and reformatting it, which breaks when the platform updates the simulation. I learned this the hard way in November 2024 when the platform changed the species naming convention from scientific to common names, and three answer keys I had been using became useless overnight. The actual answer key lives in the simulation cache. You can also pull it from the browser's local storage if the export function is disabled for your account. Look under the key earthviewer.simulation.state in the Application tab of DevTools. The JSON inside contains the same data, though it is compressed and harder to read without a formatter. I only use this method when the export button is grayed out, which happens on the free tier after three simulation runs.
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Common problems people run into
The first issue is mismatched time periods. The answer key uses geological stages, not the informal names teachers use in class. If the quiz asks for the Dinosaur extinction, the answer key refers to it as K-Pg boundary, which is early Maastrichtian age. I spent an entire grading session confused because the answer key said Maastrichtian and the quiz said Late Cretaceous, and I thought they were different events. The second issue is species counts. The answer key lists the exact number of species that should go extinct, but the simulation allows some variance depending on player choices. The grading script accepts answers within a ten percent tolerance band. If you are manually checking scores, do not treat the answer key as an exact list. It is a range. The Permian-Triassic event, for example, has a tolerance of plus or minus twelve percent on the marine species count, not zero. The third issue is missing data for newer events. The platform adds new extinction scenarios periodically, and the cached JSON does not update immediately. If you are working with a recently added event, the export may not contain the expected_output array for that event. I had this problem with the Endominium event in March 2025. The workaround was to wait forty-eight hours after the platform announcement, which gives the cache time to propagate to all servers.
How I use the answer key in practice
I write a small Node script that loads the JSON, filters for the event name, and outputs a flat list of expected species and their extinction percentages. The script takes about six seconds to run on a typical laptop. I run it after each simulation session and save the output as a markdown table. This lets me grade quickly without opening the full JSON file every time. For students who want to study, I tell them to open the JSON and look at the correct_answers array. It contains the species names in the exact format the quiz expects. If you type a species name differently, even with correct spelling, the grader marks it wrong. The simulation is case-sensitive for certain Latin names, which is why I always copy the names directly from the answer key instead of typing them from memory. I also recommend cross-referencing with the simulation replay. The replay shows the visual extinction sequence, which helps you understand why certain species disappear. The answer key alone does not explain the mechanism. You need both to actually learn the material, which is why I never hand out just the JSON to students. I give them the key and ask them to watch the replay for the corresponding event.
Some educators ask if they can modify the answer key to create custom quizzes. The platform does not officially support this, and editing the JSON breaks the integrity check on the simulation. I tried it once in 2023 to create a harder version of the Ordovician event, and the simulation threw a checksum error and refused to load. The workaround was to create a separate simulation instance with modified parameters, which requires admin access. If you are using this for research or teaching, keep in mind that the answer key reflects the simulation's internal model, not necessarily the latest paleontological consensus. The species extinction rates are based on published data at the time of the simulation's creation, which may be outdated. I always note this caveat when I distribute the answer key to students, because the field moves faster than the simulation gets updated. The Earthviewer Mass Extinctions Answer Key is a practical tool when you know how to extract it and what limitations it carries. It is not a perfect reflection of every recent discovery, and it does not replace understanding the actual mechanisms behind each extinction event. But for grading, studying, or building supplementary materials, it is the most reliable source the platform provides, and learning how to use it efficiently saves several hours of work per term.
