A newly published study has upended decades of taxonomic thinking about the Maltese Wall Lizard (Podarcis filfolensis), calling for a scientific rethink of its classification.

Authored by Arnold Sciberras, ‘The Morphological Paradox of the Maltese Wall Lizard’ highlights how visual differences across island populations, once used to define subspecies, are not supported by modern genetic data.

For years, lizards from Malta, Gozo, Comino, Filfla, and surrounding islets were classified into distinct subspecies based on variations in size, shape, and colour. However, this new research, building on genetic studies from 2014 and reinforced by a 2025 whole-genome analysis of a Filfla specimen, confirms that these populations are genetically unified.

The striking physical differences are now understood as island morphs, adaptations shaped by micro-ecosystems and isolation, not indicators of separate evolutionary branches.

Arnold Sciberras’s work critiques the outdated use of subspecies names in official documents and educational resources, arguing that taxonomy must catch up with modern science. The paper identifies two genetic clades: the Gozitan clade, covering Gozo, Comino, and nearby islets (as well as the extinct Selmunett population), and the Maltese clade, which includes Malta and its satellites. Filfla’s population, while genetically part of the Maltese group, shows unique traits due to extreme isolation.

Rather than diminishing the lizard’s uniqueness, recognising these island-specific forms within a single species celebrates their adaptability and ecological significance in the Mediterranean landscape.