''Fenestella'' is a genus of

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a l ...

ns or moss animals, forming fan–shaped colonies with a netted appearance. It is known from the Middle Ordovician to the early Upper

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

( Carnian), reaching its largest diversity during the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

. Many hundreds of species have been described from marine sediments all over the world.

Etymology

''Fenestella'' is Latin, meaning little window, from fenestra "window", for the window-like openings in the mesh of the skeleton of its colonies.

Description

The skeleton of ''Fenestella'' colonies consists of stiff branches that are interconnected by narrower crossbars (or dissepiments). Between two and eight individuals of the colony inhabit each of the opposing front sides of the approximately rectangular openings between the branches (or fenestule) in one row, and the void they left when they died can be recognized as two rows of small rimmed pores (or apertures) on the front of each branch. In well-preserved specimens these are closed by centrally perforated lids. In ''Fenestella'', the front of the branches may carry small nodes in a row in the middle. Branches split (or bifurcate) from time to time giving the colonies a fan-shaped appearance. The internal structure of the branches is of decisive importance in the assignment of specimens to genera and species, which greatly hampers identification of intact fossils. Compared to other fenestellids with two rows of apertures, ''Fenestella'' is relatively fine, with large apertures and wide dissepiments. The distance between apertures in ''Fenestella'' remains the same as colonies grow and individuals (or zooids) will have had equal size

lophophore The lophophore () is a characteristic feeding organ possessed by four major groups of animals: the Brachiopoda, Bryozoa, Hyolitha, and Phoronida, which collectively constitute the protostome group Lophophorata.homonym In linguistics, homonyms are words which are homographs (words that share the same spelling, regardless of pronunciation), or homophones (equivocal words, that share the same pronunciation, regardless of spelling), or both. Using this definition, ...

of a bivalve, now considered

synonymous A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

with '' Anomia''. In 1962 however, ''Fenestella'' was reinstated for the bryozoan genus. The misspelling ''Fenestrella'' became officially rejected. The name in the early third millennium in general was given as ''Fenestella'' Lonsdale, 1839.

Reassigned species

Because ''Fenestella'' was erected early on in paleontology, many species have since been reassigned to other Fenestellid genera. * ''F. ampla'' = '' Protoretepora ampla'' * ''F. cinctuta'' = '' Anastomopora cinctuta'' * ''F. conica'' = '' Ptiloporina conica'' * ''F. conjunctiva'' = '' Isotrypa conjunctiva'' * ''F. crassa'' = '' Fenestrellina crassa'' * ''F. jabensis'' = '' Fenestepora jabensis'' * ''F. lata'' = '' Unitrypa lata'' * ''F. laticrescens'' = '' Ptiloporella laticrescens'' * ''F. perforata'' = '' Loculipora perforata'' * ''F. quincuncialis'' = '' Lyoporella quincuncialis'' * ''F. subquadrans'' = '' Lyopora subquadrans'' * ''F. wortheni'' = '' Archimedes wortheni''

References

{{Taxonbar, from=Q20975616 Prehistoric bryozoan genera Middle Ordovician first appearances Carnian extinctions Paleozoic life of Ontario Paleozoic life of Alberta Paleozoic life of British Columbia Paleozoic life of Nunavut