Published May 30, 2022. Updated November 21, 2023. Open access. Peer-reviewed.

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Spinytail Hedgehog-Lizard (Echinosaura keyi)

Reptiles of Ecuador | Sauria | Gymnophthalmidae | Echinosaura keyi

English common names: Spinytail Hedgehog-Lizard, Spinytail Hedgehog-Lizard, Key Tegu.

Spanish common names: Lagartija erizo de cola espinosa, lagartija espinosa de Key.

Recognition: ♂♂ 18.3 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=8.0 cm. ♀♀ 15.1 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=6.0 cm..1 Hedgehog-Lizards can be differentiated from other leaf-litter lizards in their area of distribution by their stream-dwelling habits and by having a brownish dorsum with granular scales interspersed with conical scales.14 Echinosaura keyi differs from its congeners in Ecuador (E. brachycephala, E. fischerorum, E. horrida, and E. orcesi) by having a short snout, tail covered with large conical spines, and fine granular scales covering the tympanum (Fig. 1).1,5 The Ecuadorian lizard that most resembles E. keyi in external appearance is E. brachycephala, a highland species in which adult individuals have a tail covered with small conical tubercles.6 Adult males of E. keyi differ from females by having a wider head and by the presence of femoral pores.1

Figure showing variation among individuals of Echinosaura keyi

Figure 1: Individuals of Echinosaura keyi: Masphi Reserve, Pichincha province (); Itapoa Reserve, Esmeraldas province ().

Natural history: Echinosaura keyi is a rarely seen cryptozoic lizard that occurs in moist, shaded microhabitats within well-preserved lowland and foothill rainforests, particularly along streams and rivers.7 Key Tegus have been found hidden under logs, leaf-litter, and rocks during the day or at night, sometimes right alongside individuals of E. horrida and E. orcesi.7 These shy lizards are calm and even lethargic when handled; however, they are capable of biting as well as shedding the tail as methods of defense and escape.7 The function of the prominent tail spines has not been studied, but probably serves to “anchor” the lizard against slipperty crevices.

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Conservation: Vulnerable Considered to be facing a high risk of extinction in the mid-term future..8 Echinosaura keyi is listed in this category on the basis of the species’ limited extent of occurrence, which coincides with the area having the highest rate of deforestation in Ecuador.9 An estimated 83% of the total suitable habitat of E. keyi has already been converted to pastures and agricultural fields,9 an environment in which the species does not survive.8 Fortunately, E. keyi is present in Bilsa Biological Reserve, Canandé Reserve, and Mashpi Reserve.

Distribution: Echinosaura keyi is endemic to an area of approximately 16,260 km2 in the Pacific lowlands of west-central Ecuador (Fig. 2).

Distribution of Echinosaura keyi in Ecuador

Figure 2: Distribution of Echinosaura keyi in Ecuador. The star corresponds to the type locality: Río Baba Bridge, Santo Domingo de los Tsáchilas province. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Echinosaura, which comes from the Greek words echinos (=hedgehog) and saurus (=lizard)10 refers to the large dorsal spines present in some members of the genus.11 The specific epithet keyi honors American physician and amateur herpetologist Mr. George Key (1942–1999), the collector of the specimens used in the original description of the species.1

See it in the wild: Spinytail Hedgehog-Lizards are rare and secretive reptiles that appear to have become increasingly rare with the fragmentation of the Chocó rainforest in Ecuador. However, these lizards are still comparatively easy to find in Mashpi Reserve and the Bosque Privado El Jardín de los Sueños. They can be encountered by carefully turning over rocks and raking leaf-litter along well-preserved forest streams.

Special thanks to Caroline Homer for symbolically adopting the Spinytail Hedgehog-Lizard and helping bring the Reptiles of Ecuador book project to life.

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Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.

Academic reviewer: Jeffrey D CamperbAffiliation: Department of Biology, Francis Marion University, Florence, USA.

Photographer: Jose VieiracAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2023) Spinytail Hedgehog-Lizard (Echinosaura keyi). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/WCHJ6497

Literature cited:

  1. Fritts TH, Smith HM (1969) A new teiid lizard genus from Western Ecuador. Transactions of the Kansas Academy of Science 72: 54–59.
  2. Uzzell TM (1965) Teiid lizards of the genus Echinosaura. Copeia 1965: 82–89.
  3. Peters JA, Donoso-Barros R (1970) Catalogue of the Neotropical Squamata: part II, lizards and amphisbaenians. Bulletin of the United States National Museum, Washington, D.C., 293 pp.
  4. Fritts TH, Almendáriz A, Samec S (2002) A new species of Echinosaura (Gymnophthalmidae) from Ecuador and Colombia with comments on other members of the genus and Teuchocercus keyi. Journal of Herpetology 36: 349–355. DOI: 10.1670/0022-1511(2002)036[0349:ANSOEG]2.0.CO;2
  5. Yánez-Muñoz MH, Torres-Carvajal O, Reyes-Puig JP, Urgiles-Merchán MA, Koch C (2021) A new and very spiny lizard (Gymnophthalmidae: Echinosaura) from the Andes in northwestern Ecuador. PeerJ 9: e12523. DOI: 10.7717/peerj.12523
  6. Köhler G, Böhme W, Schmitz A (2004) A new species of Echinosaura (Squamata: Gymnophthalmidae) from Ecuador. Journal of Herpetology 38: 52–60. DOI: 10.1670/164-02A
  7. Field notes, Reptiles of Ecuador book project.
  8. Cisneros-Heredia DF, Yánez-Muñoz MH (2016) Echinosaura keyi. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2016-1.RLTS.T50950605A50950612.en
  9. MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
  10. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.
  11. Boulenger GA (1890) First report on additions to the lizard collection in the British Museum (Natural History). Proceedings of the Zoological Society of London 1890: 77–86.

Appendix 1: Locality data used to create the distribution map of Echinosaura keyi in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used. Asterisk (*) indicates type locality.

EcuadorCotopaxiEl Jardín de los SueñosPellet 2017
EcuadorEsmeraldasBilsa Biological ReserveOrtega-Andrade et al. 2010
EcuadorEsmeraldasItapoa ReserveThis work
EcuadorEsmeraldasVerdecanandéThis work
EcuadorPichinchaGanaderos OrensesYánez-Muñoz et al. 2021
EcuadorPichinchaMashpi Reserve (lower trails)This work
EcuadorPichinchaPuerto QuitoKöhler et al. 2004
EcuadorSanto Domingo de los TsáchilasLa Florida, 5 km W ofFritts et al. 2002
EcuadorSanto Domingo de los TsáchilasRío Baba bridgeYánez-Muñoz et al. 2021
EcuadorSanto Domingo de los TsáchilasRío Baba bridge, 4 km E of*Fritts & Smith 1969