DOI10.47051/TRWN4953

Published April 7, 2023. Updated June 7, 2026. Open access.

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Blunt-headed Shade-Lizard (Alopoglossus brevifrontalis)

Reptiles of Ecuador | Sauria | Alopoglossidae | Alopoglossus brevifrontalis

English common names: Blunt-headed Shade-Lizard, Boulenger’s Largescale Lizard, Short-faced Shade Lizard.

Spanish common names: Lagartija sombría hocicorta, lagartija de sombra de frente corta.

Recognition: ♂♂ 16.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=6.2 cm. ♀♀ 16.9 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=6.8 cm..1,2 Alopoglossus brevifrontalis is an elongated, slender lizard that can be readily distinguished from other sympatric, Amazonian leaf-litter lizards by possessing weakly striated (rather than strongly keeled) rectangular dorsal scales (Fig. 1).2–4 All other Ecuadorian members of the genus Alopoglossus feature distinctly mucronate dorsal scales that taper abruptly into sharp posterior points.5 It further differs from Arthrosaura reticulata by having four instead of three supraocular scales,6 and from Iphisa brunopereira by possessing multiple longitudinal rows of dorsal scales rather than just two expanded rows.3,7 Adult males of Ecuadorian A. brevifrontalis display notable sexual dimorphism, exhibiting shorter body lengths relative to females alongside a vibrant, bright red ventral coloration.2

Figure showing variation among individuals of Alopoglossus brevifrontalis

Figure 1: Individuals of Alopoglossus brevifrontalis: Santa Rosalía, Vichada department, Colombia (); Reventador Volcano, Sucumbíos province, Ecuador (); Río Bigai Reserve, Orellana province, Ecuador (). j=juvenile.

Natural history: Alopoglossus brevifrontalis is a rarely encountered, secretive lizard that occupies pristine to moderately disturbed lowland rainforests and lower montane evergreen forests, as well as clearings along forest borders.1,8 Blunt-headed Shade-Lizards are diurnal, cryptozoic (highly specialized for moist, deeply shaded microhabitats), and semi-fossorial.9 They actively forage both on the surface of and deep within the leaf-litter matrix, frequently seeking refuge beneath decaying logs, large rocks,3,5 or buried within the top few centimeters of friable topsoil.1,2,5 Their opportunistic diet consists primarily of spiders, small insects, and various insect larvae.10 Documented natural predators include the Surinam Horned Frog (Ceratophrys cornuta)11 and the Short-tailed Ground Snake (Taeniophallus brevirostris).9 When threatened, these shy lizards rapidly vanish into the surrounding leaf-litter; if handled, they may attempt to bite or will readily employ caudal autotomy to shed the tail.1 Reproduction is oviparous, with females producing fixed clutches of two eggs;7 gravid individuals and active nesting have been documented year-round, suggesting continuous breeding.2,10

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..12 Alopoglossus brevifrontalis is included in this category mainly on the basis of the species’ wide distribution, presence in protected areas, and presumed large stable populations.12 In the Brazilian Amazonia, about 54% of the occurrence area of A. brevifrontalis is inside protected areas and about 95% of its original forest habitat is still standing.13 The status in Ecuador is similar. Based on recent maps of vegetation cover of the Amazon basin,14 the majority (~87%) of the species’ habitat remains forested. Thus, A. brevifrontalis is considered to be facing no major immediate extinction threats.

Distribution: Alopoglossus brevifrontalis is native to an area of approximately 1,645,585 km2 in the Amazon of Bolivia, Brazil, Colombia, Ecuador (Fig. 2), French Guiana,15 Perú, and Suriname.13

Distribution of Alopoglossus brevifrontalis in Ecuador

Figure 2: Distribution of Alopoglossus brevifrontalis in Ecuador. The star corresponds to the type locality: El Topo. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Alopoglossus is derived from the Greek words alopekia (=bare) and glossa (=tongue)16 and refers to the lack of scale-like papillae in the tongue of these lizards.2,17 The specific epithet brevifrontalis is derived from the Latin words brevis (=short), front (=snout), and the suffix -alis (=pertaining to).16 It refers to the short snout.18

Where to observe: Alopoglossus brevifrontalis can be encountered with relative ease within the WildSumaco Lodge protected forest network and at the Sumak Kawsay In Situ reserve. These highly cryptic, shy reptiles are most effectively located by carefully turning over large moss-covered rocks, shifting decaying logs, or methodically clearing away accumulated leaf-litter matrices inside shaded primary and secondary forest tracts.

Authors: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: ExSitu, Quito, Ecuador. and Alejandro ArteagacAffiliation: Fundación Khamai, Reserva Arlequín, Ecoruta Paseo del Quinde km 56, Santa Rosa de Mindo, Pichincha 171202, Ecuador.

Photographers: Jose Vieira,aAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: ExSitu, Quito, Ecuador. Duvan Zambrano,dAffiliation: Universidad del Tolima, Ibagué, Colombia. Amanda Quezada,aAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: Laboratorio de Herpetología, Universidad del Azuay, Cuenca, Ecuador. and Alejandro ArteagacAffiliation: Fundación Khamai, Reserva Arlequín, Ecoruta Paseo del Quinde km 56, Santa Rosa de Mindo, Pichincha 171202, Ecuador.

How to cite? Vieira J, Arteaga A (2026) Blunt-headed Shade-Lizard (Alopoglossus brevifrontalis). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com. DOI: 10.47051/TRWN4953

Literature cited:

  1. Field notes, Reptiles of Ecuador book project.
  2. Harris DM (1994) Review of the teiid lizard genus Ptychoglossus. Herpetological Monographs 8: 226–275. DOI: 10.2307/1467082
  3. Duellman WE (1978) The biology of an equatorial herpetofauna in Amazonian Ecuador. Publications of the Museum of Natural History, University of Kansas 65: 1–352.
  4. Castro Herrera F, Ayala SC (1988) Saurios de Colombia. Unpublished, Bogotá, 692 pp.
  5. Avila-Pires TCS (1995) Lizards of Brazilian Amazonia (Reptilia: Squamata). Zoologische Verhandelingen 299: 1–706.
  6. Diago-Toro MF, García-Cobos D, Brigante-Luna GD, Vásquez-Restrepo JD (2021) Fantastic lizards and where to find them: cis-Andean microteiids (Squamata: Alopoglossidae & Gymnophthalmidae) from the Colombian Orinoquia and Amazonia. Zootaxa 5067: 377–400. DOI: 10.11646/zootaxa.5067.3.3
  7. Vitt LJ, Magnusson WE, Avila-Pires TCS, Pimentel Lima A (2008) Guide to the lizards of Reserva Adolpho Ducke, Central Amazonia. Áttema Design Editorial, Manaus, 176 pp.
  8. Camper JD, Torres-Carvajal O, Ron SR, Nilsson J, Arteaga A, Knowles TW, Arbogast BS (2021) Amphibians and reptiles of Wildsumaco Wildlife Sanctuary, Napo Province, Ecuador. Check List 17: 729–751.
  9. Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
  10. Duellman WE (2005) Cusco amazónico: the lives of amphibians and reptiles in an Amazonian rainforest. Cornell University Press, Ithaca, 433 pp.
  11. Duellman WE, Lizana M (1994) Biology of a sit-and-wait predator, the leptodactylid frog Ceratophrys cornuta. Herpetologica 50: 51–64.
  12. Calderón M, Perez P, Avila-Pires TCS, Aparicio J (2019) Alopoglossus brevifrontalis. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2019-2.RLTS.T203062A2759731.en
  13. Ribeiro-Júnior MA, Amaral S (2016) Diversity, distribution, and conservation of lizards (Reptilia: Squamata) in the Brazilian Amazonia. Neotropical Biodiversity 2: 195–421. DOI: 10.1080/23766808.2016.1236769
  14. MapBiomas Amazonía (2022) Mapeo anual de cobertura y uso del suelo de la Amazonía. Available from: www.amazonia.mapbiomas.org
  15. Dewynter M, Godé L, Girardot T, Courtois EA (2020) First record of Ptychoglossus brevifrontalis Boulenger, 1912 (Squamata, Alopoglossidae) in French Guiana. Check List 16: 155–161. DOI: 10.15560/16.1.155
  16. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.
  17. Boulenger GA (1885) Catalogue of the lizards in the British Museum. Taylor & Francis, London, 497 pp.
  18. Boulenger GA (1912) Descriptions of new reptiles from the Andes of South America, preserved in the British Museum. Annals and Magazine of Natural History 10: 420–424.

Appendix 1: Locality data used to create the distribution map of Alopoglossus brevifrontalis in Ecuador (Fig. 2). Asterisk (*) indicates type locality.

CountryProvinceLocalitySource
ColombiaAmazonasEl EncantoSINCHI 3316; Caicedo Portilla et al. 2023
EcuadorMorona SantiagoComunidad Shuar KunkukFacebook photo by Gustavo Pazmiño
EcuadorMorona SantiagoMacumaUIMNH 66151; not examined
EcuadorMorona SantiagoRío CusuimeRibeiro-Júnior & Amaral 2016
EcuadorNapoHidroeléctrica Coca Codo SinclairMECN & ENTRIX 2009–2013
EcuadorNapoPacto SumacoReptiles of Ecuador book database
EcuadorNapoWild Sumaco Wildlife SanctuaryCamper et al. 2021
EcuadorOrellanaYasuni Scientific StationReptiles of Ecuador book database
EcuadorPastazaAbitaguaHarris 1994
EcuadorPastazaMera, environs ofHarris 1994
EcuadorPastazaOglán AltoHarris 1994
EcuadorPastazaPozo DantaOrtega-Andrade 2010
EcuadorPastazaPucayacu (Río Pucayacu)Harris 1994
EcuadorPastazaRío Arajuno, headwaters ofHarris 1994
EcuadorPastazaRío CorrientesHarris 1994
EcuadorPastazaSumak Kawsay In SituBentley et al. 2021
EcuadorPastazaTzarentzaReptiles of Ecuador book database
EcuadorSucumbíosBoca del Río CuyabenoHarris 1994
EcuadorSucumbíosEl ReventadorAvila-Pires 1995
EcuadorSucumbíosGarzacochaiNaturalist; photo examined
EcuadorSucumbíosHostería ReventadorReptiles of Ecuador book database
EcuadorSucumbíosLa BalsareñaiNaturalist; photo examined
EcuadorSucumbíosLimococha Biological ReserveReptiles of Ecuador book database
EcuadorSucumbíosPuerto LibreHarris 1994
EcuadorSucumbíosRío PutumayoDiago-Toro et al. 2021
EcuadorSucumbíosSanta Cecilia Harris 1994
EcuadorTungurahuaEl Topo*Boulenger 1912
EcuadorTungurahuaReserva Río ZuñacOnline multimedia
EcuadorZamora ChinchipeNangaritzaReptiles of Ecuador book database
EcuadorZamora ChinchipeZamoraHarris 1994
PerúAmazonasBoca del Río SantiagoRibeiro-Júnior & Amaral 2016
PerúLoretoCentro UniónHarris 1994
PerúLoretoRedondocochaYánez-Muñoz & Venegas 2008
PerúLoretoRío AmpiyacuRibeiro-Júnior & Amaral 2016