The Lagostomus crassus is a possibly extinct species from Peru. Its species-hood has been a source of question for over 100 years. That controversy continues to this day. The skull was collected by Jan Kalinowski around 1894. It is known that the skull was collected in Saint Ana, Peru in the District of Cusco near Machu Picchu. The skull was sent with many other specimens from Peru to be studied and cataloged. In 1910, Michael Roger Oldfield Thomas studied the skull and gave it the name Lagostomus crassus. In Latin ‘crassus’ means fat or gross. Some places list this species as the ‘dwarf’ viscacha which doesn’t make sense given the larger, stouter description of the species based on measurements of the skull. Because the skull was found over 600 miles from the closest living viscacha species it was thought to have gone extinct and a rare find. In the 1960’s and later echoed by some scientists in the 1990’s, it was proposed that the skull was transported there by a traveler going to Cusco. Some scientists point to markings on the skull that could be cut marks. They think this viscacha was someone’s lunch. After eating a common plains viscacha from 600 miles away, they disposed of the skull in Peru. This is not impossible given the 25,000 miles road system created by the Incas throughout South America. In fact the Inca had messengers or runners they called “chasqui” who could travel 200 miles in a day. That means that a plains viscacha caught and eaten over a three day run could in theory have been deposited in Peru. Other studies as recently as 2016, have stated that the measurements between the Lagostomus crassus and Lagostomus maximus (plains viscacha) just don’t match up in size. Because no other specimens have ever been collected in Peru it may be impossible to solve this one hundred year old debate. What is known, is that there are no known species of viscacha in or near Peru today. Although Jurassic Park is fiction, scientists are working on several de-extinction projects. In fact, in 2003 scientists did bring back the extinct Pyrenean ibex, a type of wild goat, for 7 minutes before it died, showing de-extinction is possible. The Lagostomus crassus is only known from one skull. If DNA could be extracted from that skull, then maybe science could bring back the dwarf viscacha. If that were to happen, scientists could finally solve this extinct species mystery. If the dwarf viscacha was ever brought back could it survive again in Peru?