Monodelphis domestica (Burnett 1830, Pine et al. 2013) is the extant gray short-tailed opossum. Monodelphis is traditionally considered a member of Didelphidae, a group of exclusively New World opossums thought to be basal among the living marsupials.
Despite having prepubes, Monodelphis does not have a pouch and skeletal traits nest it at the base of the Eutheria, the placental therians. Monodelphis is approximately 50 times smaller in body size than Didelphis, The dental formula is: 5.1.3.4 and 4.1.3.4 as in other didelphids. Note (below) that even smaller species of Monodelphis, like M. kunis, are extant and known. These have three molars per side, as in many basal placentals.
Kraus and Fadem 1987 report: litter size ranged from 2 to 13 with a m:f gender ratio of 1:1. Females typically have 13 teats that can be retracted into her body. After a 14-day gestation, 1cm young emerge and attach to a teat. The young grow hair after 3 weeks, open their eyes a week later, and are weaned at eight weeks. Sexual maturity occurs after 5 months of age and monodelphids live to 4 years old.
Images from Digimorph.org used with permission. |
