🦎 These chameleons have fooled scientists for decades

For decades, scientists have classified chameleons primarily based on their external morphology. This traditional approach has sometimes led to persistent taxonomic confusion, particularly for species with similar characteristics.

Madagascar, an island off the east coast of Africa, is recognized as a biodiversity hotspot for chameleons. More than 40% of documented species reside there, including the commonly called Pinocchio chameleon, observed for nearly 150 years. This group, known as the Calumma gallus species complex, is distinguished by the elongated nasal appendages of the males.


Recent genetic analyses have revealed that the Pinocchio chameleon actually constitutes a distinct species, officially named Calumma pinocchio. This discovery is based on the study of DNA from specimens preserved in museums, challenging classifications based solely on nose shape.


Researchers have identified a second new species, Calumma hofreiteri, previously associated with Calumma nasutum due to morphological similarities. The analysis of evolutionary relationships showed that nasal appendages can evolve rapidly, possibly influenced by female preferences during mate selection.


The method used, called museomics, allows for extracting DNA from historical specimens, with the oldest dating back to 1836. According to the researchers, this approach opens new perspectives for correcting misidentifications in species complexes, as stated by Professor Miguel Vences from the Technical University of Braunschweig.


With these two new descriptions, Madagascar now counts exactly 100 chameleon species, out of a global total of 236.

Museomics

Museomics is a scientific technique that allows for analyzing DNA from specimens preserved in museums. It uses historical samples, sometimes decades old, to extract genetic sequences. This method is particularly useful for rare or extinct species, where recent collections are impossible.

In taxonomy, museomics helps resolve confusions related to identification based on morphology. For example, chameleons stored since the 19th century have provided crucial data for distinguishing new species. This avoids relying solely on physical traits, which can vary with the environment.

Technological advances in DNA sequencing have made museomics more accessible. It allows for revising old classifications without requiring new field expeditions. Thus, collections become valuable resources for evolutionary research.