Buried in Gondwana: A Cretaceous Predecessor of Chameleons Unearthed in Madagascar
A newly described fossil lizard from the Late Cretaceous of Madagascar provides critical insight into the deep evolutionary history of acrodontan iguanians, the group that includes modern chameleons and agamids. The specimen, recovered from the upper Anembalemba Member of the Maevarano Formation, is dated to the Maastrichtian stage, approximately 70–66 million years ago. It exhibits a suite of cranial and dental features consistent with early acrodontan morphology. Its discovery extends the known temporal range of chameleon-lineage lizards and supports a Gondwanan origin for the clade. Further records of related taxa may help clarify its exact phylogenetic position.
Chameleons (Chamaeleonidae) are among the most morphologically specialized lizards, with a distribution centered in Africa and Madagascar. Despite their ecological prominence, the fossil record of chameleons and their close relatives remains sparse, particularly for pre-Cenozoic intervals. Molecular phylogenies have long suggested a Cretaceous origin for acrodontan iguanians, but direct fossil evidence has been lacking.
Recent fieldwork in northwestern Madagascar has yielded a nearly complete lizard fossil from the upper Anembalemba Member of the Maevarano Formation. Stratigraphic correlation places the specimen firmly within the Maastrichtian stage of the Late Cretaceous (70–66 Ma). The fossil, designated Cryptovaranoides primus, displays diagnostic traits of early acrodontans, including pleurodont-to-acrodont dental transition, fused frontal bones, and a reduced postorbital bar. These features place it near the base of the acrodontan radiation, offering a rare glimpse into the ancestral morphology of the group.
The Maevarano Formation is a Late Cretaceous sedimentary unit exposed in the Mahajanga Basin of northwestern Madagascar. It comprises three members: Masorobe, Anembalemba, and Miadana. Most vertebrate fossils, including Cryptovaranoides primus, originate from the upper Anembalemba Member, which consists of poorly sorted clay-rich sandstones deposited in a seasonal, semiarid fluvial environment. Radiometric and biostratigraphic data confirm a Maastrichtian age, placing the fossil within the final 4 million years of the Cretaceous.
Systematic Paleontology
Order: Squamata
Clade: Iguania
Group: Acrodonta
Genus et species: Cryptovaranoides primus gen. et sp. nov.
The holotype includes a nearly complete skull and partial postcranial elements. Micro-CT analysis reveals internal cranial architecture consistent with acrodontan affinities. The dentition includes anterior pleurodont teeth transitioning to posterior acrodont implantation, a key synapomorphy of the clade.
The discovery of Cryptovaranoides primus fills a critical gap in the fossil record of acrodontan iguanians and supports a Gondwanan origin for the group. Its presence in Madagascar aligns with molecular divergence estimates and suggests that the lineage leading to modern chameleons was already established in the Late Cretaceous.
Whether Cryptovaranoides is a direct ancestor of chameleons or a close collateral relative—perhaps a grand-grand-uncle rather than a grand-grand-father—remains to be resolved. But its anatomical mosaic and temporal placement make it a vital piece of the evolutionary puzzle. It reminds us that the roots of Madagascar's iconic reptiles stretch deep into Gondwanan soil, long before the island's isolation.
From the red sandstones of the Maevarano Formation, Cryptovaranoides primus emerges as a sentinel of deep time. It may not yet wear the crown of direct ancestry, but it stands close enough to the throne to be honored. So let us cordially welcome this ancient figure, whether forebear or uncle, into the chameleon lineage. Science may one day decide its exact role, but its presence alone is a gift to evolutionary history.
Marke, D., Whiteside, D.I., Sethapanichsakul, T., Coram, R.A., Fernandez, V., Liptak, A., Newham, E. & Benton, M.J. 2025. The oldest known lepidosaur and origins of lepidosaur feeding adaptations. Nature 622: 112–117. https://doi.org/10.1038/s41586-025-09496-9.