A newly identified prehistoric species, Terastiodontosaurus marcelosanchezi, has stunned paleontologists by becoming the largest known worm lizard ever discovered. According to the study published in Zoological Journal, this ancient reptile, measuring more than 3 feet long, this ancient reptile pushes the boundaries of what scientists previously thought possible for this group of burrowing creatures.
The Ancient Reptile That Broke Every Rule
Discovered in Djebel Chambi National Park, Tunisia, the fossils of T. marcelosanchezi date back to approximately 50 million years ago, during the Eocene epoch. Unlike modern-day worm lizards, which are typically small, limbless, and adapted for life beneath the surface, this behemoth likely roamed above ground.
“This is large for amphisbaenian standards,” said Georgios Georgalis, lead author of the study, referencing the typically modest size of this group. The discovery challenges previous assumptions about the biology and ecology of amphisbaenians, the squamate reptiles to which worm lizards belong.
Real-life Sandworm? The Anatomy Of An Ancient Giant
The reptile’s massive frame and formidable jaw have drawn comparisons to the iconic sandworms from the Dune franchise.
“Visually, you can imagine the animal as a ‘sandworm’ from the ‘Dune’ science fiction novels and their movie adaptation,” Georgalis explained.
The comparison is not just dramatic—it underscores the animal’s likely appearance and feeding strategy. Armed with thick tooth enamel and exceptionally strong jaw muscles, T. marcelosanchezi was probably a specialized predator of snails, using brute force to crush hard shells.
“Based on the tooth structure and the unusually thick enamel, we can deduce that the animals had enormous muscle strength in their jaws.”
Largest Worm Lizard Ever Found
With an estimated skull length exceeding 2 inches, this species surpasses all previously known worm lizards—both extinct and living. Extrapolating from related species, scientists propose that T. marcelosanchezi is the largest member of the Trogonophid family, a small North African lineage of worm lizards. These reptiles are distinct in their skull and tooth architecture, tail morphology, and burrowing habits.
The fossils—consisting mainly of jaws and vertebrae—were found across a range of sizes, indicating multiple individuals were preserved.
Clues From a Warmer Earth
The study hints at a connection between the animal’s unprecedented size and the global climate of the Eocene epoch, which was notably warmer than today.
“We think that the unusual body size is related to the higher temperatures in this period of the Earth’s history,” said co-author Krister Smith from the Senckenberg Research Institute in Frankfurt.
This trend, if confirmed, would align with broader patterns seen in other Eocene reptiles, suggesting that elevated temperatures favored larger body sizes.
Evolutionary Oddity With A Powerful Bite
Modern trogonophids are typically obscure and rarely grow beyond a few inches in length, but this ancient relative broke the mold entirely. The research team identified “extreme” and “unique” dental features.
These anatomical adaptations likely gave the lizard a highly effective and destructive bite, turning it into a formidable predator within its ecosystem. Its unusually large body size and surface-dwelling behavior point to a significant evolutionary departure from the burrowing habits seen in its modern relatives.
The discovery of Terastiodontosaurus marcelosanchezi broadens the known range of worm lizard diversity and provides new insight into how reptiles adapted to the environmental conditions of prehistoric Earth.
