A new species of Leptobrachella Smith 1925 (Anura, Megophryidae) from Lai Chau Province, Vietnam.

Background: The genus Leptobrachella (Anura, Megophryidae) was originally described, based on the type species from Sarawak (Malaysia), Leptobrachella mjöbergi Smith. The taxa in the group were previously classified into different genera, i.e, Paramegophrys Liu; Leptolalax Dubois; Lalax Delorme, Dubois, Grosjean & Ohler; and Lalos Dubois, Grosjean, Ohler, Adler & Zhao. However, Yuan et al. synonymised Leptolalax with Leptobrachella in 2017. Members of Leptobrachella inhabit the forest floor and rocky streams in hilly evergreen forests. They are widely distributed from southern China and Myanmar through mainland Indochina to Peninsular Malaysia and the island of Borneo. However, the species diversity of the genus was indicated to be underestimated by phylogenetic analyses and a series of new species have been discovered recently. In Vietnam, 34 species of Leptobrachella are currently known and 75% (or 24 species) have been described or newly recorded from the country since 2010.

New information: We describe a new species, Leptobrachellahuynhi sp. nov., from Sin Ho District, Lai Chau Province. The new species is distinguished from its congeners by genetic divergences ranging from 3.62 to 18.51% (16S rRNA gene) and morphological differences: size medium (SVL 37.8-40.2 mm in adult females); head longer than wide; tympanum distinct; skin on entire dorsum shagreened; toes without webbing and with narrow lateral fringes; supratympanic ridge slightly rough with few nodules; dorsum grey-brown with indistinct dark brown markings; an interorbital region with a stacking double Y-shaped marking; centre of belly creamy-white, outer edges of belly brown with small whitish spots; iris copper. The new species is the 35^th species of the genus Leptobrachella known from Vietnam.