Phillips’ small-eared shrew is found in the mountains of Oaxaca, southern Mexico. It has a relatively long tail and is known from high-elevation forests, including cloud forest.
Its tail averages about 31 mm, or 46% of head-and-body length. The forepaws are somewhat enlarged, and the foreclaws are elongated and somewhat broader than in many other members of the genus.
Phillips’ Small-eared Shrew inhabits moist mountain forest in southern Mexico, including wet slopes with tree ferns and stream margins surrounded by cloud forest. At San Agustín Chayuco, coffee plantations also occur around the stream-side collection site.
A 2020 paper re-examined five unidentified museum specimens. Comparisons of their external features and skulls identified them as this species. Two had been collected beside a stream and three on a wet slope near another village, all in 2009.
The two sites lay about 60 kilometres west of the nearest previously known localities. The stream-side site was across the Río Verde, which interrupts the mountain chain. Identifying stored specimens broadened its known distribution. Both western localities also documented moist forest or streamside habitat.
An extinction-risk assessment has not been added yet.
The 2020 authors called for continued surveys in poorly sampled areas and renewed examination of museum specimens and their associated records. They also identified the effects of coffee cultivation at San Agustín Chayuco as a question for further research. Establishing where populations occur and how surrounding land use affects them supports regional conservation decisions.