Muscul

Muscul is a genus of extinct small to medium-sized rodents that lived during the late Paleocene to the Early Eocene epoch. They were part of the family Muscinae, which also includes Old World mice and rats. The name Muscul is derived from the Latin word "musclus", meaning "mussel", likely referring to the genus' snout morphology, somewhat resembling a mussel shell.

Fossils of Muscul were found in the Bank of the San Pedro rock formation in Bolivia, in the Argentina portion of Patagonia, and in other areas in South America and Europe. The species included in this genus are relatively small in size, with adults reaching up to 20 centimeters (8 inches) in length. Muscul was most likely an herbivore, judging from their tooth structure and jaw position.

These rodents had typical rodent dental morphology, featuring prominent wear of their molars due to grinding diet containing a high share of hard seeds and some softer plant remains. Although generally similar in structure, some differences can be seen in the larger conch shapes and morphology of their front maxilla between the regions where discovery was made.

Muscul appears to have been distributed across the Paleocene and Eocene epochs in South America. These regions, then undergoing climatic warming, offered suitable ground for these creatures to expand towards endemic zones without any refining migration. Due to ongoing changes in climate and the habitat's distribution and availability, their widespread geographic occurrences and continued coexistence came to an end. As with many species discovered during this era, details remain limited and the ongoing load of fossil discoveries are there to confirm specific facts about Muscul.