Dictyunellidae

Dictyunellidae is a family of extinct marine invertebrates belonging to the order Dictyonellida. These organisms are known from the fossil record, primarily from the Paleozoic Era. Their defining characteristic is a porous, net-like skeletal structure, often described as reticulate or dictyonine. This skeletal framework was typically composed of silica, although some variations may have existed.

The precise biological affinities of Dictyunellidae have been a subject of debate among paleontologists. Historically, they have been grouped with sponges, particularly siliceous sponges, due to the porous nature of their skeletons. However, some researchers have suggested alternative interpretations, considering them as potentially related to other extinct marine groups or even as an entirely separate phylum. Their lifestyle is presumed to have been sessile, attaching to the seafloor or other substrates.

Fossil specimens of Dictyunellidae are found in various marine sedimentary rocks. Their distribution appears to be global, with notable occurrences in regions that preserve Paleozoic marine life. The exact ecological role of Dictyunellidae within their ancient ecosystems is not well understood, but like many sessile filter-feeders, they likely played a part in nutrient cycling and providing habitat for smaller organisms. Further research is needed to fully elucidate their evolutionary history and taxonomic placement.