DISTRIBUTION RANGE EXTENSION OF THE AMAZON PYGMY GECKO PSEUDOGONATODES GUIANENSIS (PARKER, 1935) (SPHAERODACTYLIDAE: GEKKOTA) IN NORTHERN SOUTH AMERICA

The expansion of the distribution range of the Amazonian pygmy gecko Pseudogoinatodes guianensis is carried out based on a record from Colombia in the eastern flank of the Eastern Cordillera.

Pseudogonatodes guianensis, commonly named as the Amazon Pygmy Gecko, is a terrestrial and diurnal species that is highly adaptable to different ecosystems, inhabiting both primary and secondary terra firme forests, swampy areas, and disturbed habitats (Duellman & Mendelson, 1995;Vitt et al., 2005;Arteaga, 2023).The species is the most widely distributed species of the genus, with its distribution primarily cis-Andean (Avila-Pires, 1995;Riveiro-Junior, 2015).It has been recorded in Brazil, Guyana, Venezuela, Colombia, Ecuador, Peru, Suriname and The genus Pseudogonatodes (Ruthven, 1915), belonging to the family Sphaerodactylidae, constitutes a group of small geckos, mainly semifossorial or cryptozoic, with cis-and trans-Andean distribution in northern South America (Avila-Pires, 1995;Avila-Pires & Hoogmoed, 2000;Esqueda et al., 2016).The genus shares characteristics with other sphaerodactylids, such as Lepidoblepharis, leading to the initial inclusion or synonymization of species (e.g., Lepidoblepharis lunulatus, later designated as Pseudogonatodes lunulatus; P. furvus, initially considered a synonym of L. intermedius, later recognized as a nominal species) (Ruthven, 1922;Parker, 1926;Roux, 1927).Currently, the genus Pseudogonatodes is diagnosed by the presence of a retractile claw between five scales, where the supralateral scales of the claw sheath are in contact through their length (Peters & Donoso, 1970;Avila-Pires, 1995).
On August 4, 2021, at 18:30 h, during a field trip, a lizard was observed on the rocky shore of the upper reaches of San Pedro  The specimen was photographed and euthanized it with 2% Roxicaine, muscle tissue (hind limb) was removed and preserved in 95% ethanol, then fixed it in a 10% formalin solution and preserved it in 70% ethanol.The specimen has been deposited in the Museo de Herpetología de la Universidad de Antioquia (MHUA) under the catalog number MHUA-R13964 (Fig. 1) and was collected under the authorization of the Autoridad Nacional de Licencias Ambientales (ANLA), resolution number 00644, dated April 7, 2021.
The species most similar to P. guianensis is P. lunulatus, although, according to Esqueda et al. (2016), they can be differentiated: P. guianensis has (vs.P. lunulatus in parenthesis) the sole of the foot with heterogeneous squamation (homogeneous squamation), tibia foot < 0.5 regarding the femur length (>0.5 regarding the femur length), and the first supralabial 0.5 or less regarding eyenostril distance (> 0.5 to ≤ 0.7 eye-nostril distance) (Fig. 2).This record signifies the northernmost occurrence of the species in South America and one of the few confirmed Andean records for the species P. guianensis.Consequently, the latitudinal distribution of the species extends approximately 420 kilometers from the north of the Casanare department (Hato Colosal municipality) to the east of Cesar department (Curumaní municipality), both sites in Colombia (Fig. 3; Appendix 1.).Thus, it is proposed that the distribution of the gecko P. guianensis encompasses the Amazon Basin, the Guiana Shield, and the  The inter-Andean record in the Magdalena River valley in the Tolima department is intriguing (MPUJ-R634, Appendix 1.), although it could not be confirmed, so it may be a case of misidentification.Nevertheless, there is an increasing number of records for small ectotherms with a cis-Andean distribution in the inter-Andean valleys, as observed in the case of the glass frog Cochranella resplendens (Lynch & Duellman, 1973), the colubrid snake Atractus occipitoalbus (Jan, 1862), the lizard Anolis fuscoauratus (D'Orbigny, 1837) and the microteiid Cercosaura argulus (Peters, 1862) (see Grisales-Martínez et al., 2017;Marín et al., 2017;Molina-Zuluaga et al., 2017;Diago-Toro et al., 2021).
Small cryptic geckos of the genus Pseudogonatodes can be misclassified due to their morphological similarity with other genus in the family Sphaerodactylidae (e.g., Sphaerodactylus), or due to the similarity among congeners.Therefore, the collection of individuals in the field and subsequent laboratory analysis is crucial for understanding the true distribution of the species, its intra-specific variation, and species boundaries.This is particularly important for P. guianensis, to assess whether the phenotypic divergence exhibited by Andean populations (as suggested by Avila-Pires, 1995 and Hoogmoed & Avila-Pires,  Grisales-Martínez -Range extension of Pseudogonatodes guianensis 2000) may coincide with genetic divergence, thus positioning these populations as candidate species.
The species P. guianensis is listed as Least Concern (LC) according to Red List of the International Union of Conservation of Nature (IUCN), due to large distribution, lack of evidence for significant population decline, lack of widespread threats, and occurrence in numerous protected areas (Calderón et al., 2019).However, the true distribution and population trends at the Andean level are unknown, thus the record of the present study is relevant for a future evaluation.
Acknowledgments.-I thank ISA Intercolombia for providing the data used in the wildlife monitoring of the compensation areas related to the environmental impact study "EIA Línea de Transmisión La Loma-Sogamoso a 500 kV" for this publication.I express gratitude to Eliecer Cuadros and his family for their hospitality during my stay on their farm.Special thanks to biologist Manuela Santamaría, Victor Lizarazo, and the staff of Consferdal for their assistance during the fieldwork.I also extend my thanks to Betriz Rendón for her contribution to the improvised version of this manuscript and to the reviewers for their comments.Finally, thanks to the Museo de Herpetología de la Universidad de Antioquia (MHUA) and Grupo Herpetológico de Antioquia (GHA) for providing me with workspace.

Figure 2 .
Figure 2. Specimen ofPseudogonatodes guianensis (MHUA-R13964).(A) dorsal view of head, showing three postrostral scales and a "W"-shaped light area on posterior part of head; (B) ventral view of foot, red arrow indicates sole of foot with heterogeneous squamation; (C) dorsal view of foot, showing a sheath of supralateral scales in contact across its length.Scale bar = 1 mm.

Figure 3 .
Figure 3. Distribution map of Pseudogonatodes guianensis.The green star indicates the new record, the yellow circle indicates the type locality (approximate, as cited in the original description by Parker, 1935, in the Upper Cuyuni river, British Guiana), the blue circle indicates the inter-Andean record, and the red circles represent records based on museum records obtained from GBIF.