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RESEARCH PRODUCT

Evolutionary trends of Triassic ammonoids.

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description

The Triassic represents a key interval in the evolutionary history of ammonoids. Characterized by the dominance of the Ceratitida with their typical suture line indented on the lobes only, the Triassic quasi-monophyletic clade shows a remarkable biostratigraphic and geographic record. However, very few studies have thoroughly investigated their evolutionary trends, except for taxonomic richness. Although Triassic ammonoids show a very large range of morphologies, suture complexity and adult size, little is currently known about their trends, except for peculiar time intervals or taxonomic groups. Nevertheless, it seems that taxonomic diversity and morphological disparity of Triassic ammonoids are uncoupled, at least during part of the Early Triassic recovery. Finally, Triassic ammonoids still have many properties to contribute to evolutionary biology, but going further now requires the construction of quantitative databases of the various morphological characters and reconstruction of Triassic ammonoid phylogeny.