[3] The specific name, petteri, honors French zoologist Francis Petter for his contributions to the study of Malagasy rodents.

[5] Petter's big-footed mouse is a terrestrial rodent with short forelimbs and long hindfeet.

[7] The upper sides of the feet are covered with grayish white fur, which extends around the claws to form ungual tufts.

It has a well-developed tuft at its tail tip, consisting of whitish and occasional light brown hairs.

[4] Petter's big-footed mouse has a large and robust skull with well-developed zygomatic arches (cheekbones).

[12] The animal was found in an isolated fragment of dry deciduous forest amid land cleared for maize cultivation.

[5] Although only a single individual of Petter's big-footed mouse was caught during Goodman and Soarimalala's survey, which accrued 3100 trap-nights, they argue that this does not necessarily mean the species is rare, since trapping rates for rodents in the dry forests of Madagascar are often variable depending on year and season.

[13] Subsequent to its discovery at the Mikea Forest, Petter's big-footed mouse was also found as a subfossil in cave deposits at Andrahomana in far southeastern Madagascar, a find reported in 2006.

Two Petter's big-footed mouse bones were radiocarbon dated to 790–410 BCE and 150–390 CE, respectively, a period when the local climate became drier and humans first appeared.

[11] Macrotarsomys species are thought to burrow in sandy ground and would not be expected to enter caves; therefore, the subfossils are probably remains of animals eaten by birds of prey.

Although Petter's big-footed mouse could conceivably persist in remnant pockets of wet habitat in southeastern Madagascar, searches at two sites near Andrahomana failed to confirm its presence.

[17] A karstic deposit near Lake Tsimanampetsotsa (dated to the Late Pliocene or Early Pleistocene on unclear grounds) contained three species of Macrotarsomys, including a very large one that may well be M. petteri.