A new species of the genus (Anura, Megophryidae) from Southwest China.

BACKGROUND

The Asian horned toad subfamily Megophryinae (Bonaparte, 1850) currently comprises more than 140 species and is widely distributed in southern China, as well as in Tropical Asia from India and Bhutan to the Philippines. During amphibian surveys conducted at Mt.Daxue Nature Reserve on June 28-30, 2023, we collected specimens of within the genus . Based on molecular phylogenetic analyses and morphological comparisons, we describe this taxon as a new species from southwestern China.

NEW INFORMATION

Molecular phylogenetic analyses based on mitochondrial DNA strongly support the new species as a sister species of . The uncorrected genetic distances between the 16S rRNA and COI genes between the new species and its closest congener were 9.3% and 8.1%, respectively. The new species could be distinguished from its congeners by a combination of the following characters: (1) adult males have a moderate body size (SVL 37.1-40.6 mm), differing from in having longer hindlimbs when adpressed anteriorly-the tibiotarsal articulation reaches the mid-level of the eye when extended (vs. only reaching the area between the tympanum and the eye in ); (2) vomerine ridge present and vomerine teeth absent; (3) tongue not notched behind; (4) a small horn-like tubercle at the edge of each upper eyelid; (5) tympanum distinctly visible, rounded; (6) toes lacking lateral fringes and webbing; (7) Distinct relative finger lengths: II < I < V < III in the new species (vs. I < II < V < III in ); (8) heels overlapping when thighs are positioned at right angles to the body; (9) tibiotarsal articulation reaching the level of the middle of the eye when leg is stretched forward; (10) an internal single subgular vocal sac in male; (11) dense nuptial spines on dorsal bases of fingers I and II in breeding adult males;(12) Eye diameter (ED) significantly smaller than that of (ED: 4.00±0.28 in the new species vs. 5.00±0.38 in , P < 0.05).