Two new species ofSaurichthys(Actinopterygii: Saurichthyidae) from the Middle Triassic of Monte San Giorgio, Switzerland, with implications for character evolution in the genus

Two new species of the iconic Triassic fish genus Saurichthys have been identified from the Middle Triassic Besano Formation at Monte San Giorgio, Switzerland: S. breviabdominalis, distinguished by its elongated operculum and reduced abdominal region, and S. rieppeli, notable for its block-like haemal arches and unique fin structures. Phylogenetic analysis reveals that S. rieppeli occupies a basal position among Alpine Triassic saurichthyids, supporting hypotheses of convergent evolution in scale reduction within the genus. Meanwhile, S. breviabdominalis forms a monophyletic group with local congeners, suggesting sympatric divergence—a finding that sheds light on ecomorphological divergence and resource partitioning in Triassic marine ecosystems. The study leverages detailed morphological analysis to elucidate character evolution and ecological adaptations in saurichthyid fishes.

Maxwell, E. E., Romano, C., Wu, F., & Furrer, H. (2015). Two new species ofSaurichthys(Actinopterygii: Saurichthyidae) from the Middle Triassic of Monte San Giorgio, Switzerland, with implications for character evolution in the genus. Zoological Journal of the Linnean Society, 173(4), 887–912. https://doi.org/10.1111/zoj.12224