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The Ecuadorian Horned Anole (Anolis proboscis) is one of three species of anole lizards known as "proboscis anoles". This group, which is also known as the A. laevis group (Williams 1979), consists of A. laevis, A. proboscis, and A. phyllorhinus. Members of all three species have a striking scaly anterior (forward) extension of the snout (Poe et al. 2012).
All three species of proboscis anoles were originally described based on extremely few specimens, all of which were males, and for many decades there were no reported observations of living specimens. The first females of any of these three species were reported by Rodrigues et al. (2002, cited in Losos et al. 2012), who described females of A. phyllorhinus from Amazonian Brazil. Prior to 2005, when a group of birders encountered and photographed a male A. proboscis crossing a road in Mindo, Ecuador (Almendáriz and Vogt 2007), A. proboscis had not been reported since the last specimen was collected in 1966 (Losos et al. 2012). Subsequently, there have been a small number of additional records. Yánez-Muñoz et al. (2010, cited in Losos et al. 2012) described variation in five specimens of A. proboscis (including the first females of this species) that were located in 2007 and 2008 in two areas 11 to 13 km north of previous records. In August and December of 2009, Poe et al. (2012) found and collected 11 additional specimens along a paved road within 5 km of Cunuco, the type locality for this species. Losos et al. (2012) captured 20 individuals as part of their field study in and near Mindo.
Poe et al. (2012) note that the scarcity of specimens of A. laevis and A. phyllorhinus is perhaps unsurprising given their ranges: The single specimen of A. laevis (collected in the mid-19th century) was from a mountain trail connecting two lower elevation towns in Peru and A. phyllorhinus is an Amazonian forest form with an apparently narrow distribution. The scarcity of A. proboscis in collections may be a bit more surprising since the type locality is in a populated area within a 3 hour drive of Quito along a well-traveled, paved road and is frequented by both ecotourists and scientists. However, Losos et al. (2012) attribute the fact that these anoles are rarely observed to their morphology and behavior. They are cryptic in pattern and coloration, move very slowly, and appear to spend most of their time in dense vegetation high off the ground where they are almost impossible to observe.
Based on field observations and measurements, Losos et al. (2012) concluded that, except for its striking proboscis, A. proboscis closely matches the "twig ecomorph" that has evolved multiple times on islands in the Greater Antilles: among other similarities, these anoles are cryptically colored, small, and short-limbed with a narrow head and a tail that is at least somewhat prehensile. The proboscis that gives this group of anoles its name is absent in females of both A. phyllorhinus and A. proboscis (A. laevis females are still unknown). Losos et al. note that although the function of the male's proboscis has not been studied, it is extremely flexible and would clearly not be an effective weapon, although it seems likely that it serves to intimidate other males and/or help attract potential mates.
Poe et al. (2012) reported morphological data from both newly collected and previously preserved specimens of the species, including some characters not previously scored for this species; discussed the results of a phylogenetic analysis aimed at determining the placement of this species within Anolis; and presented new information on the color, behavior, and ecology of A. proboscis in life. Losos et al. (2012) described the results of their behavioral and ecological field study of this species near Mindo, Ecuador.
Although much about A. proboscis remains unknown, much has been learned about this species since its rediscovery, making it by far the best studied of the proboscis anoles. Anolis phyllorhinus remains poorly known and A. laevis is still known from just the preserved specimen from Peru described in 1876. The phylogenetic relationships of all proboscis anoles remain poorly understood (Poe et al. 2012; Losos et al. 2012).