Figure 1 Geographic distribution of Alopoglossus vallensis in Colombia. The blue dot indicates the type locality (Río Pance, 2,5 km vía la Vorágine, Valle del Cauca, Colombia), the yellow dots indicate previously published localities in the departments of Cauca and Valle del Cauca (^{Harris 1994}; ^{Hernández et al. 2019, 2020}), and the white triangles indicate localities in the departments of Antioquia, Caldas, Cauca, Quindío, Risaralda and Valle del Cauca based on previously unpublished museum specimens (see Appendix 1). 

The Alopoglossidae is a Neotropical lizard family composed of 32 recognized species that are generally diurnal and cryptic inhabitants of leaflitter (^{Hernández-Morales et al. 2020}; ^{Ribeiro-Junior et al. 2021}; ^{Uetz et al. 2021}). Many alopoglossid species were traditionally in the genus Ptychoglossus (e.g., ^{Harris, 1994}; ^{Bolívar-G and Hernández-Morales 2013}). However, a recent analysis of morphological and multilocus genetic data by ^{Hernández-Morales et al. (2020)} recommended that Ptychoglossus be synonymized with Alopoglossus due to paraphyly. We follow this taxonomic position herein while recognizing that it remains contested by some authors (e.g., ^{Ribeiro-Junior et al. 2021}). Alopoglossus vallensis is one of these former Ptychoglossus species, and it is one of 21 alopoglossid species distributed in Colombia (^{Harris, 1994}; ^{Uetz et al. 2021}). It has been recorded in the Cauca River Valley and the western Andes of Colombia (departments of Cauca and Valle del Cauca), in tropical dry forest and premontane humid forest from 1 000-1 700 m elevation (^{Harris, 1994}; ^{Castro-Herrera and Vargas-Salinas, 2008}; ^{Hernández-Morales et al. 2019}). Alopoglossus vallensis differs from all Colombian congeners except A. stenolepis in having 36-45 scale rows around the midbody, widely separated prefrontal scales, a comparatively elongated body, and narrow dorsal scales (^{Harris, 1994}). It differs from A. stenolepis in several features including hexagonal dorsal scales (vs. quadrangular scales in A. stenolepis), posterior chin shields that are similar in size to the second pair (vs. distinctly smaller than the second pair), a snout that slopes straight in lateral profile (vs. rounded), and hemipenes with 17 flounces (vs. eight) (^{Harris, 1994}; ^{Bolívar-G and Hernández-Morales, 2013}).

Figure 2 Morphological comparison of Alopoglossus vallensis and A. stenolepis. First row: lateral view of head (note straight vs. curved snout profile); second row: dorsal view of head (note separated prefrontal scales); third row: ventral view of head (note posterior chinshields similar in size to second pair vs. distinctly smaller than second pair); fourth row: dorsal scales of body (note hexagonal vs. quadrangular shape). See Appendix 1 for specimen locality data. 

In this note, we report both northern and southern range extensions for A. vallensis in Colombia, and we also expand its known elevational range and climatic tolerances. We assembled pre-existing records for the species by referencing relevant primary literature (^{Harris, 1994}; ^{Castro-Herrera and Vargas-Salinas, 2008}; ^{Hernández-Morales et al. 2019}), and we assembled new records through our own fieldwork and by examining previously unpublished specimens deposited in several Colombian collections (Appendix 1). In total, we identified 18 novel A. vallensis specimens collected from 18 localities across the departments of Antioquia (seven localities), Caldas (one locality), Cauca (one), Quindío (six), Risaralda (one), and Valle del Cauca (two) (Fig. 1, Appendix 1). Certain diagnostic features of two of the new A. vallensis specimens are shown in Fig. 2. Cumulatively, the new specimens are the first from the departments of Antioquia, Caldas, Quindío, and Risaralda, and extend the species' known elevational range from 1 000 - 1 700 m to 730 - 1 925 m (Fig. 1). Geographically, the new records extend the distribution of A. vallensis over 282 km northward (straight line measured in Google Earth) into the Central Andes of Colombia, and 29.8 km southward. The previous northernmost published record was from Parque Las Heliconias, Caicedonia, Valle del Cauca (CZPD-UV 3070, 3071, 3073, 3074, 3077, 3080; ^{Hernández-Morales et al. 2019}), while the new northernmost record is MHUA-R-10212 from Vereda Guacabe, Yolombó, Antioquia (Appendix 1). The previous southernmost published record was from Santander de Quilichao, Cauca (CZPD-UV 2034, 2051, 2269, 2274), while the new southernmost record is from Finca La Albania, Vereda Camilo Torres, Piendamó, Cauca (MHUA-R 13093). The annual mean range of temperature and precipitation for the 16 new localities (16.5 - 24.5 °C, 1758 - 3 922 mm/year; data downloaded from www.worldclim.org) also expands the range of environmental conditions from those of the nine localities where A. vallensis was previously reported (19.0-24.0 °C, 1 160 -1 925 mm/year). Thus, our new records further broaden scientific understanding of the ecological tolerances of this species.