Taxa described in 2000

The Mycocaliciales are an order of ascomycetous fungi within the subclass Mycocaliciomycetidae and within the class Eurotiomycetes (subphylum Pezizomycotina).

Jenkinidae is a family of sea sponges in the order Leucosolenida.

Rhizomarasmius is a genus of fungi in the family Physalacriaceae, containing about five species.

Syconessa is a genus of sponges in the family Heteropiidae.

Sphingomonadaceae are a gram-negative bacterial family of the Alphaproteobacteria. An important feature is the presence of sphingolipids (mainly 2′-hydroxymyristoyl dihydrosphingosine 1-glucuronic acid, "SGL-1") in the outer membrane of the cell wall. The cells are ovoid or rod-shaped. Others are also pleomorphic, i.e. the cells change the shape over time. Some species from Sphingomonadaceae family are dominant components of biofilms.

Polyglyphanodontia, also known as the Borioteiioidea, is an extinct clade of Cretaceous lizards. Polyglyphanodontians were the dominant group of lizards in North America and Asia during the Late Cretaceous.

Limnognathia is a genus of microscopic acoelomate freshwater animal that was discovered in Disko Island, Greenland, in 1994. Since then, it has also been found on the Crozet Islands of Antarctica as well as in the British Isles and the Spanish Pyrenees, suggesting a worldwide distribution. There are two known species of Limnognathia: L. maerski, described in 2000, and L. desmeti, described in 2025.

The Delitschiaceae are a family of fungi in the order Pleosporales. Taxa are widespread, especially in temperate regions, and are saprobic, often found growing in herbivore dung.

Baimashania is a genus of flowering plants belonging to the family Brassicaceae.

Leucandrilla is a genus of calcareous sponge belonging to the family Grantiidae.

Protopannaria is a genus of seven species of lichen-forming fungi in the family Pannariaceae. The genus was elevated from a subgenus of Pannaria to full genus status in 2000. Protopannaria lichens typically grow as small, overlapping patches on mossy tree trunks and branches in humid, old-growth forests. The genus is primarily distributed in subantarctic and temperate regions of the Southern Hemisphere.

Topeliopsis is a genus of lichen-forming fungi in the family Graphidaceae.

Stigmatochroma is a genus of lichenized fungi in the family Caliciaceae. The genus has a widespread distribution, and contains 9 species.

Baculifera is a genus of lichens in the family Caliciaceae. It was circumscribed in 2000 by Bernhard Marbach and Klaus Kalb. Species in this genus are characterized by having bacilliform conidia typically measuring 8–11 μm long, and a non- hymenium. The genus is roughly similar in morphology to Buellia.

Ideorhipistena is a genus of tumbling flower beetles in the family Mordellidae. Ideorhipistena occipitalis is the sole species of this genus.

Culbersonia is a fungal genus in the family Caliciaceae. This is a monotypic genus, containing the single foliose lichen Culbersonia nubila (formerly called Culbersonia americana). This species, which grows on trees and rocks, is found in dry subtropical regions of the world, particularly in Africa and Central America.

Pseudoramonia is a genus of lichen-forming fungi in the family Graphidaceae. The genus was circumscribed by lichenologists Gintaras Kantvilas and Antonín Vězda in 2000, with the type species designated as Pseudoramonia stipitata.

Telogalla is a genus of lichenicolous fungi in the family Verrucariaceae. It has two species. The genus was circumscribed by Nikolaus Hoffmann and Josef Hafellner.

Japewiella is a genus of lichen in the family Lecanoraceae. It was circumscribed in 2000 by German botanist and lichenologist Christian Printzen as a segregate of the genus Japewia. The genus name of Japewia was in honour of Peter Wilfrid James (1930 - 2014), who was an English botanist (Mycology and Lichenology). The genus was circumscribed by Christian Printzen in Bryologist vol.102 on page 715 in 1999.

Leucascandra is a monotypic genus of sponges belonging to the family Jenkinidae. The only species in this genus is Leucascandra caveolata.

Endohyalina is a genus of 10 species of corticolous (bark-dwelling) crustose lichens in the family Caliciaceae. These lichens either form thin, tightly attached crusts on tree bark or live as parasites on other lichens, sometimes becoming so reduced that they are nearly invisible to the naked eye. They produce small, black, disc-shaped fruiting bodies that begin buried in the crust and later emerge flush with the surface, containing spores that are divided once by a cross-wall and darken to brown as they mature.

Loftusiida is an order of foraminifers in the class Globothalamea.

Halorhabdus is a genus of halophilic archaeans in the Haloarculaceae. With an extremely high salinity optimum of 27% NaCl, Halorhabdus has one of the highest reported salinity optima of any living organism.

Cratiria is a genus of lichen-forming fungi in the family Caliciaceae. The genus has a widespread distribution, especially in tropical regions, and contains about 20 species. The genus was circumscribed by Austrian lichenologist Bernhard Marbach in 2000, with Cratiria lauri-cassiae assigned as the type species.

Phaeomoniella is a genus of hyphomycete fungi in the family Celotheliaceae. The genus was circumscribed by Pedro Crous and Walter Gams in 2000 to contain the type species, P. chlamydospora, the causal agent of Petro grapevine decline, a disesase in the esca disease complex. Phaeomoniella is similar to Phaeoacremonium, differing in cultural characteristics, and in the morphology of the conidiophores and conidia.

Hypoflavia is a genus of lichenized fungi in the family Caliciaceae. The genus in found in South America, especially in tropical regions, and contains two species.

Polejaevia is a genus of sponges belonging to the family Jenkinidae. The only species in this genus is Polejaevia telum (Lendenfeld, 1891).