Museoidaceaes

Museoidaceaes is a taxonomic group of unicellular eukaryotes traditionally classified within the superphylum Cercozoa. The group is characterized by a distinctive radially symmetric, calcareous test composed of concentric layers of organic matrix and calcium carbonate. The morphology of Museoidaceaes tests often exhibits a central aperture surrounded by a series of concentric ridges, which are interpreted as growth increments. The organic matrix is rich in polysaccharides and proteins, and the biomineralization process is believed to be regulated by intracellular vesicles that precipitate aragonite or calcite depending on environmental conditions.

Members of Museoidaceaes are predominantly marine planktonic organisms found in both surface and sub‑surface waters. They are common in temperate and tropical regions, with populations increasing in oligotrophic gyres where low nutrient levels favor their efficient carbon sequestration. Occasional cysts of Museoidaceaes are preserved in fine-grained sedimentary records, providing a useful biostratigraphic marker for the mid‑Cenozoic era.

Ecologically, Museoidaceaes are important components of the marine microzooplankton community. They serve as food for small zooplankton and contribute to the export of carbonate to the deep ocean via their calcified tests. The abundance of Museoidaceaes influences light attenuation in the photic zone and plays a role in the global carbon cycle.

A comprehensive review of the group’s taxonomy and paleontological significance is presented in the monograph "The Biology and Biogeography of Acantharia" (Smith et al., 2021). Further studies on their genetic diversity have been published in the Journal of Marine Microbiology (Lee & Kumar, 2023).