Image: Cavy (1)

Description: Note: This capybara is not particularly large. I have one that is larger and have seen live capybaras with likely larger skulls. Guinea pigs are also rather big-headed in terms of rodent body proportions. Regardless, the size disparity is obvious. Here is the largest rodent in the world, the capybara, with its close cousin, the guinea pig, atop its head. Some taxonomists put the capybara in its own family, the Hydrochoeridae, while other lump it into Caviidae, the guinea pig family. Regardless, capybaras are more closely related to caviids than other rodents, and both belong the remarkable South American radiation of caviomorph rodents, hysticomorphous rodents (note the large infraorbital foramen) that accidentally made their way across the Atlantic in the Eocene while South America was still splendidly isolated from the rest of the continents. There were many caviomorphs larger than the capybara before modern times, including rhino sized dinomyids.
Title: Cavy (1)
Credit: Capybara (Hydrochoerus hydrochaeris) and Guinea Pig (Cavia porcellus) skulls Uploaded by FunkMonk
Author: Dallas Krentzel
Usage Terms: Creative Commons Attribution 2.0
License: CC BY 2.0
License Link: https://creativecommons.org/licenses/by/2.0
Attribution Required?: Yes