''Ivanovia'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of marine

green algae The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ...

belonging to the order Bryopsidales and family

Codiaceae Codiaceae is a family (biology), family of green algae in the order Bryopsidales. Genera * † ''Abacella'' Maslov * † ''Appeninocodium'' O.Dragastan * † ''Arabicodium'' G.F.Elliott * ''Bevocastria'' E.J.Garwood * ''Botryella'' V.P.Shu ...

. Species belonging to the genus lived from the Pennsylvanian to the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

and have been found in the Moscow basin, North America, Italy, Tunisia, and China. Members of the genus have thalli (leaflike photosynthetic structures) that are cyathiform (cuplike in shape.) There are indications that asexual reproduction took place through budding of the thalli. Sexual reproduction also took place, through reproductive structures in stalked outgrowths of the thalli (

oogonia An oogonium (: oogonia) is a small diploid cell which, upon maturation, forms a primordial follicle in a female fetus or the female (haploid or diploid) gametangium of certain thallophytes. In the mammalian fetus Oogonia are formed in lar ...

and

gametangia A gametangium (: gametangia) is a sex organ or cell in which gametes are produced that is found in many multicellular protist A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists ...

, the female and male reproductive structures of green algae.) Bioherms (fossil algal mounds) constructed by ''Ivanovia'' are prominent in the Paradox Formation of the

Colorado Plateau The Colorado Plateau is a physiographic and desert region of the Intermontane Plateaus, roughly centered on the Four Corners region of the Southwestern United States. This plateau covers an area of 336,700 km2 (130,000 mi2) within w ...

, where they are important

petroleum reservoir A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the prese ...

s. It is possible that ''Ivanovia'' is a taphotaxon of '' Anchicondium '' or '' Eugonophyllum''; that is, a characteristic diagenetic alteration of an original fossil organism that lacks taxonomic significance.

References

Paleozoic life Codiaceae Ulvophyceae genera {{Ulvophyceae-stub