Feeding specialization in Late Triassic fishes

The ichthyofauna of the Zorzino Limestone represents an important proof of the richness and variety reached by bony fishes during the Norian and, at the same time, it testifyies the beginning of the faunal transition which will be realized during the Jurassic. The thousands of specimens and the extraordinary quality of preservation found in the fossiliferous levels of this unit allowed, in the last years, not only to follow such a crucial moment in the evolution of vertebrates, but also to reconstruct the mode of life and the trophic adaptations reached by the different groups, living in the depositional basins. As evidence of this peculiar evolutionary period, the large predators at the highest trophic levels are still represented by ’primitive’ basal actinopterygians; on the contrary, the most derived neopterygians specialized in durophagy, a trophic niche previously almost unexploited by actinopterygians. Within the main trophic categories, anyway, we can find different morphological specializations, which probably allowed the fishes to exploit most of the available trophic resources.