Two main landscapes emerge from the Guiana Shield: the highlands to the west called the Pantepui region and the Amazonian lowlands to the east, both harbouring numerous endemic species. With 32 currently recognized species, the genus Anomaloglossus stands out among Neotropical frogs as one that diversified only within the Guiana Shield both in the highlands and the lowlands. We present a time-calibrated phylogeny obtained by using combined mitogenomic and nuclear DNA, which suggests that the genus originates from Pantepui where extant lineages started diversifying around 21 Ma, and subsequently (ca. 17 Ma) dispersed during the Miocene Climatic Optimum to the lowlands of the eastern Guiana Shield where the ability to produce endotrophic tadpoles evolved. Further diversification within the lowlands in the A. stepheni group notably led to an evolutionary reversal toward exotrophy in one species group during the late Miocene, followed by reacquisition of endotrophy during the Pleistocene. These successive shifts of reproductive mode seem to have accompanied climatic oscillations. Long dry periods might have triggered evolution of exotrophy, whereas wetter climates favoured endotrophic forms, enabling colonization of terrestrial habitats distant from water. Acquisition, loss, and reacquisition of endotrophy makes Anomaloglossus unique among frogs and may largely explain the current species diversity. The micro evolutionary processes involved in these rapid shifts of reproductive mode remain to be revealed.

圭亚那地盾有两个主要景观：西部的高地（称为潘特普伊地区）和东部的亚马逊低地，两者都栖息着许多特有物种。奇舌蛙属目前已识别出 32 个物种，在新热带蛙类中脱颖而出，因为它只在圭亚那地盾内的高地和低地发生多样化。我们提出了通过使用组合的线粒体基因组和核 DNA 获得的时间校准的系统发育，这表明该属起源于 Pantepui，那里现存的谱系在 21 Ma 左右开始多样化，随后（约 17 Ma）在中新世气候最适宜期间分散到低地圭亚那地盾东部，这里进化出了产生内养蝌蚪的能力。低地地区的斯蒂芬尼种群进一步多样化，在中新世晚期导致一个物种群体的进化逆转为外养型，随后在更新世期间重新获得内养型。生殖模式的这些连续转变似乎伴随着气候的波动。长期干旱可能引发了外养型的进化，而潮湿的气候则有利于内养型，从而能够在远离水源的陆地栖息地进行殖民化。内养生物的获得、丧失和重新获得使奇舌蛙在青蛙中独一无二，并可能在很大程度上解释当前的物种多样性。这些生殖模式快速转变所涉及的微观进化过程仍有待揭示。