Two new species of Eleutherodactylus (Anura: Eleutherodactylidae) from Southern Mexico, with comments on the taxonomy of related species and their advertisement calls

An analysis of morphological and molecular data is presented here, as well as notes on advertisement calls from populations of the Eleutherodactylus nitidus species group (subgenus Syrrhophus) from southern Mexico, and two new species are described based on the results. Eleutherodactylus maculabialis sp. nov. is unique among its congeners by a combination of characters including widely expanded finger tips, indistinct but visible inguinal glands, a dark venter, and conspicuous orange or pale cream spots present on the upper lip. Eleutherodactylus sentinelus sp. nov. is unique among its congeners by the combination of its advertisement call, smooth dorsal and ventral skin, and a unique combination of a brown dorsum, pale interorbital bar and mid-dorsal stripe, and bright yellow inguinal flash coloration. The molecular phylogenetic analysis indicates that both species are part of the Eleutherodactylus nitidus species group, and closely related to one another. Known collecting localities for both new species suggest they are restricted to small ranges in moist pine-oak woodland, cloud forest, and oak-tropical deciduous forest on the windward slopes of the Sierra Madre del Sur in Guerrero. We discuss the relationships of the new species to all the species in the Eleutherodactylus nitidus species group and the validity of some related taxa based on the results of our phylogenetic analysis. The male advertisement calls of the new species are presented graphically, along with those of the closely related species occurring in the Sierra Madre del Sur. Range maps are presented for all species of the Eleutherodactylus nitidus species group, as the group is currently understood.