Laretiidae

Laretiidae is a family of extinct marine invertebrates belonging to the class Conulariida. These organisms existed from the Ordovician period to the Triassic period. Conulariids, including Laretiidae, are characterized by their distinctive conical or pyramidal shells, often referred to as tests or coralliths. These structures were typically made of a chitinophosphatic material, a unique composition among invertebrates, and were composed of four convex outer sides.

Fossils of Laretiidae are found in marine sedimentary rocks worldwide, providing insights into ancient marine ecosystems. The exact lifestyle and feeding habits of Laretiidae remain a subject of scientific investigation. However, their sessile or semi-sessile nature is generally inferred from the morphology of their fossilized remains. Some researchers suggest they may have attached themselves to hard substrates or burrowed partially into soft sediment. Their taxonomic placement within the broader group of cnidarians has been debated, with some proposing relationships to modern jellyfish or corals, while others suggest a more distant or even independent evolutionary lineage. The extinction of Laretiidae, along with many other marine life forms, is often linked to major extinction events that occurred throughout the Paleozoic and Mesozoic eras.