Early Cretaceous diversification of Neogastropoda

A new fossil (Early Cretaceous) marine snail, Fimbrivasum bulgaricum provides rare evidence of the early evolution of Neogastropoda – one of today’s most diverse groups of predatory gastropods. This fossil pushes the origin of the family Vasidae back to the Barremian, about 125 million years ago, and shows that major neogastropod lineages had already diverged well before their mid-Cretaceous radiation. The discovery also highlights serious discrepancies between fossil and molecular evidence, emphasizing the need for further study of early neogastropod evolution.

Figure: Left: Reconciliation of the Neogastropoda fossil record with its phylogenetic tree, rooted in the earliest record of Buccinoidea. Right: Apical view of the newly discovered species showing the arrangement of varices and the method used to measure their spacing. Numbers indicate the sequence of varix formation during shell growth.