The Ellimmichthyiformes, also known as double-armored herrings, are an extinct order of ray-finned fish known from the Late Jurassic to the Oligocene. They were the sister group to the extant true herrings, shad and anchovies in the order Clupeiformes, with both orders belonging to the suborder Clupeomorpha. Some studies suggest that the order may be potentially paraphyletic with respect to crown-group Clupeiformes.
The Ellimmichthyiformes, also known as double-armored herrings, are an extinct order of ray-finned fish known from the Late Jurassic to the Oligocene. They were the sister group to the extant true herrings, shad and anchovies in the order Clupeiformes, with both orders belonging to the suborder Clupeomorpha. Some studies suggest that the order may be potentially paraphyletic with respect to crown-group Clupeiformes.
A highly successful group throughout the Cretaceous, they were found worldwide and are known to have inhabited both marine and freshwater habitats. They appear to have been a largely marine group for most of their history, with the first freshwater lineages appearing during the Late Cretaceous. In 2026, the Ancashichthyidae, the earliest known ellimmichthyiforms (and clupeomorphs as a whole), were described from the Late Jurassic of Peru.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).