Fenestrata is an extinct order 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 ...

n, dating from the Upper

Arenig In geology, the Arenig (or Arenigian) is a time interval during the Ordovician period and also the suite of rocks which were deposited during this interval. History The term was first used by Adam Sedgwick in 1847 with reference to the "Arenig ...

. Most fenestrate bryozoans formed net-like colonies, often in funnel- or fan-shaped forms, with a single layer of zooids facing one direction. The colony shape served as a filter-feeding apparatus that water currents flowed through, with autozooecial apertures only on the side of the colony facing into the current. This colony structure was vulnerable to predators, so some fenestrate bryozoans produced skeletal superstructures, likely to strengthen or protect the colony, and others had protective spines surrounding their autozooecial apertures. Some sources consider ''Fenestrata'' to be a synonym of '' Fenestrida'', while others treat them as separate orders.

References

Prehistoric bryozoans Prehistoric animal orders Stenolaemata Extinct bryozoans {{paleo-protostome-stub