Mythic Peruvian Anoles Rediscovered – Anole Annals

The rediscovery of Anolis laevis is one of those stories that seem written to remind us why biological exploration remains indispensable. Described in 1876 from a single specimen, holotype ANSP 11368, and then lost to science for a century and a half, this small anole with a strange proboscis on its snout became a myth of the montane forests of northeastern Peru. For more than a decade, herpetologist Pablo Venegas conducted repeated and systematic surveys throughout the region, from 2003 to 2018, intensively searching the same montane forests without finding a single trace of the elusive Swordsman anole, reinforcing its reputation as a species that might have vanished forever.

Holotype of Anolis laevis ANSP 11368 (SVL = 60.0 mm). Head in dorsal (A), lateral (B), and ventral (C) views. Body in dorsal (D), and ventral (E) views. Tail in ventral (F) view.

The work reported in our recent paper began quietly in 2008, when two adult females were collected in Laguna Negra, in the department of San Martín, Peru, without anyone knowing at the time that they held the key to solving a historical enigma. Ten years later, in 2018, two adult males appeared in Posic and Nuevo Chirimoto, confirming that the “swordsman anole” was still alive. It was at that moment that a systematic investigation began which, after years of comparing morphology, reviewing historical collections, and documenting living individuals, succeeded in bringing to light a species that had remained in the shadows for generations.

The process was as captivating as it was rigorous. Researchers compared every detail of the new specimens with the 19th-century holotype, a specimen that is deteriorated but still retains the diagnostic characteristics that define the species. The male’s small rostral proboscis and dorsal crest formed by triangular scales are still visible, features that match precisely with the rediscovered animals, dispelling fears that this was a different cryptic species. The study also revealed a surprising sexual dimorphism: the females, unknown until now, completely lack a proboscis but have a black gular fold with white scales, while the males have a pink gular fold with a bluish border. This revelation not only completed the portrait of A. laevis, but also provided an essential piece of the puzzle for understanding how sexual selection and visual signaling operate in these Andean anoles.

Sexual dimorphism in Anolis laevis.

The work condenses decades of uncertainty into a powerful visual sequence. The holotype allows us to observe, from dorsal, lateral, and ventral views, that even after 150 years of preservation, the key features are still there, anchoring the species’ identity to the present. The photographs reveal a lichen-colored lizard, almost camouflaged among moss and damp leaves, and show the female with her dark dewlap deployed for the first time. Comparison with other proboscis anoles, such as A. phyllorhinus from Brazil and A. proboscis from Ecuador, highlights a fascinating evolutionary truth: although these “big-nosed” lizards look alike, they belong to different lineages.

Species of Anolis with proboscis. Anolis laevis adult male (A); A. phyllorhinus adult male (B); A. proboscis adult male (C).

Another plate contrasts A. laevis with similar species from Ecuador and Peru, A. peruensis, A. lososi, A. williamsmittermeierorum, and A. orcesi, highlighting diagnostic differences in scales, crests, and dewlaps. Finally, the distribution map locates the four known points of the species in San Martín, just 50–100 km from the holotype area, delineating a presence that is as real as it is fragile.

Dewlaps of males and females of four species from Ecuador and Peru belonging to the nasofrontalis series clade: Anolis laevis male (A) and female (B); A. peruensis male (C) and female (D); A. williamsmittermeierorum male from Peru (E) and female (F); A. williamsmittermeierorum male from Ecuador (G) and female (H); and A. lososi male (I) and female (J). Additionally, dewlaps of Anolis orcesi (heterodermus series clade) are shown: male (K) and female (L).

The culmination of this scientific journey also brings with it a warning. Anolis laevis inhabits very humid montane forests between 1,700 and 1,990 m in altitude, in a strip of the Huallaga basin that has been intensely fragmented by agriculture and colonization. With an estimated range of only ~1920 km², the authors propose that the species be considered Endangered under IUCN criteria, a reminder that the miracles of biodiversity can disappear as quickly as they are rediscovered. And yet, the story is deeply optimistic: from the unnoticed females of 2008 to the males of 2018 that sparked the research, Anolis laevis has regained its place in human knowledge. Phylogenetic analyses and new explorations lie ahead, but the myth is no longer a myth; it is now a living species, with a face, colors, and a future that depends on our ability to conserve the forests that hid it for 150 years.

Distribution of Anolis laevis, A. peruensis and A. williamsmittermeierorum in Perú.

Behind this reconstruction is an international team led by myself, along with Pablo Venegas, Luis García-Ayachi, and Steven Poe, from institutions in Ecuador (UTE University, INABIO, Great Leaf), Perú (Rainforest Partnership, Peruvian Institute of Herpetology), and the United States (University New Mexico University), who combined fieldwork, morphological analysis, and a review of literature and collections. Although the study offers an exhaustive redescription, the authors are clear that the evolutionary story is still being written: the molecular phylogeny of Anolis laevis is in the process of being established to accurately determine its relationships within the heterodermus–nasofrontalis clade. Previous evidence indicates that the proboscis has evolved convergently at least three times in Anolis, and everything points to the Peruvian “swordsman” representing an independent chapter in that innovation. When genetic sequences become available, it will be possible to refine its position and better understand how the Andes and the Amazon have shaped these lineages.

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