A fossil unearthed from Triassic-era rocks near Bristol has been confirmed as the oldest modern lizard, dating back an astounding 205 million years. This discovery, originally identified by researchers from the University of Bristol, dramatically shifts the timeline of lizard evolution, pushing the origins of modern lizards back by 35 million years.
Initially, the findings sparked debate, with some scientists questioning whether the fossil was indeed a lizard. However, a recent study published in Royal Society Open Science has put those doubts to rest. New analyses confirm that the fossil is closely related to modern anguimorphs, such as monitors and anguids. This research solidifies its place within the Squamata group, the larger reptilian order that includes both lizards and snakes.
The fossil was named Cryptovaranoides microlanius by the Bristol team—meaning “hidden lizard, small butcher”—due to its sharp teeth, which likely helped it tear into prey. The fossil’s skull and skeletal structure matched those of modern lizards, especially within the Anguimorpha sub-group, which includes species like the Komodo dragon.
The initial study faced significant skepticism, especially after a 2023 paper suggested the fossil was not a lizard at all, but rather an archosauromorph, a group of reptiles more closely related to crocodiles and dinosaurs. Dr. David Whiteside, one of the study’s authors, explains that despite the criticism, the team was confident in their analysis. They meticulously compared the fossil to a wide range of specimens, ensuring their conclusions were sound.
In response to the challenges, the Bristol team conducted a thorough review of their original work, including a deeper analysis of the fossil using CT scans. These scans provided additional insights into the specimen’s anatomy, further confirming its classification as a lizard.
This discovery not only reshapes our understanding of lizard evolution but also provides valuable insights into the broader history of reptiles. As more fossils from the Triassic period are examined, researchers expect to uncover even more details that could challenge current scientific perspectives on reptilian origins.
