image: Fossilized skeleton of Triassurus sixtelae with interpretive drawing. view more
Credit: Image credit: Rainer R. Schoch.
Researchers report a fossil specimen that may represent an ancestor of salamanders. Little fossil evidence exists to connect the features of tetrapods in the Paleozoic era with lissamphibians, a group that contains all living amphibians, in the Mesozoic era. This fossil gap renders the origins of modern amphibians unclear. Rainer R. Schoch and colleagues report a specimen of Triassurus sixtelae, a tetrapod from the middle to late Triassic discovered in Kyrgyzstan. The fossil is better preserved, larger, and more mature than a previously identified larval specimen and contains features suggesting that it may be an ancestor of salamanders. Geological context suggests that T. sixtelae may have lived in a shallow lake environment. Salamander-like characteristics of the skull, vertebrae, and trunk show evolution of the salamander body plan. The fossil specimen also contains features similar to an order of tetrapods called temnospondyls, but with differences that place it in an evolutionary relationship above the temnospondyls and within the batrachians, a group that includes modern frogs and salamanders. According to the authors, the specimen extends the fossil record of salamanders by around 60-74 million years and suggests that Eurasia may be the point of origin for salamanders, which may have dispersed via land bridges in the Triassic Period.
Article #20-01424: "A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders," by Rainer R. Schoch, Ralf Werneburg, and Sebastian Voigt.
MEDIA CONTACT: Rainer R. Schoch, Staatliches Museum für Naturkunde Stuttgart, GERMANY; e-mail: rainer.schoch@smns-bw.de
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Journal
Proceedings of the National Academy of Sciences