It is placed in the subgenus Tyrrhenicola, alongside its probable ancestor, the early Middle Pleistocene species Microtus (Tyrrhenicola) sondaari, which probably descended from a population of Allophaiomys that arrived in Sardinia between 1.2 million and 0.8 million years ago. The arrival of Microtus (Tyrrhenicola) on Sardinia marks a faunal turnover event from the Early Pleistocene Nesogoral faunal complex and the Middle-Late Pleistocene Microtus (Tyrrhenicola) faunal complex.[1] The oldest dates for M. henseli are over 500,000 years old.[1] The youngest dates for the species on Sardinia around 1300 BC, while in Corsica the species is suggested to have become extinct between 393 BC and the 6th century AD. It may have become extinct as a result of introductions of invasive species to the islands by humans.[2]
Description
Microtus (Tyrrhenicola) henseli had an estimated body mass of approximately 277 grams (0.611 lb), substantially larger than its mainland ancestors, an example of island gigantism.[3]