Tethyan Triassic Fishes from Europe to China

In northern Italy a rich succession of Middle-Late Triassic fish-rich units represents the western Tethys coastal environments. Many taxa have been recently described, also providing an interesting and quite complete stratigraphic record. The most representative sites of this fossil fauna are at the boundary between Italy and Switzerland where, in the Monte san Giorgio area, the Middle Triassic yields at least seven superimposed different fish assemblages. Further fish assemblages are found in the Early Carnian and in the Norian of the Italian Prealps. The stratigraphic record of these units has been confidently defined, allowing very reliable comparisons inside the Tethys realm: in some other sites, in fact, both in the Westernmost regions (Spain) and in the Far East (China) fossil fishes are coming to light. At Montral-Alcover (Catalunia, Spain) the early Ladinian fish fauna shows a remarkable resemblance at generic level (Peltopleurus, Luganoia, Eosemionotus, Habroichthys, Eoeugnathus, Peltoperleidus, etc.) with some of the lower units of Monte San Giorgio and of the new sites in the Italian Prealps. It is also possible that the affinity could reach the specific level, but the scanty preservation of Spanish specimens prevents a detailed analysis. This faunal province can be extended as far as to the East: a few genera (Guizhouniscus, Brachysomus, Guizhouamia) recently described from the Ladinian and Carnian of the Guizhou Province (Southern China) appear very close to the European taxa (Aneurolepis, Eosemionotus, ‘Caturus’). Though, these Chinese fish faunas have a still insufficient stratigraphic support . It is worth pointed out also that most of these taxa are of very small size- less than 10 cm in standard length- and they all lived in coastal lagoons. The extension of the Tethys faunal province is further supported by the geographical distribution of shallow-water reptiles such as the nothosaurid Lariosaurus, which was also described for the first time in northern Italy and then studied in Spain and China.