Editing Bryozoa (section)

=== Fossil record ===
[[File:OilShaleFossilsEstonia.jpg |thumb |Bryozoan fossils in an Upper [[Ordovician]] oil shale ([[kukersite]]), northern [[Estonia]].]]
{{stereo image
 |image = Arhimedes3d.jpg
 |caption = Fossilized skeleton of [[Archimedes (bryozoan)|Archimedes Bryozoan]]
 |width = 450
 |height = 200
}}
Fossils of about 15,000 bryozoan species have been found. Bryozoans are among the three dominant groups of Paleozoic fossils.<ref name="Bryozoan Evolution">{{cite news |last1=McKinney |last2=Frank K |last3=Jeremy |title=Bryozoan Evolution |publisher=Boston: Unwin & Hyman, 1989}}</ref> Bryozoans with calcitic skeletons were a major source of the carbonate minerals that make up limestones, and their fossils are incredibly common in marine sediments worldwide from the Ordovician onward. However, unlike corals and other colonial animals found in the fossil record, Bryozoan colonies did not reach large sizes.<ref name="Phylum Bryozoa">{{cite book |last1=Ernst |first1=Andrej |title=Phylum Bryozoa |date=2020 |pages=11–56 |chapter=2- Fossil record and evolution of Bryozoa}}</ref> Fossil bryozoan colonies are typically found highly fragmented and scattered; the preservation of complete zoaria is uncommon in the fossil record, and relatively little study has been devoted to reassembling fragmented zoaria.<ref>{{cite journal |last1=Jackson |first1=Patrick N. Wyse |last2=Key |first2=Marcus M. Key Jr. |title=Epizoan and endoskeletozoan distribution across reassembled ramose stenolaemate bryozoan zoaria from the Upper Ordovician (Katian) of the Cincinnati Arch region, USA |journal=Australasian Palaeontological Memoirs |date=2019 |volume=52 |pages=169–178}}</ref> The largest known fossil colonies are branching trepostome bryozoans from Ordovician rocks in the United States, reaching 66 centimeters in height.<ref name="Phylum Bryozoa"/>

The oldest species with a [[biomineralization|mineralized]] skeleton occurs in the Lower [[Ordovician]].<ref name="Taylor2013" /> It is likely that the first bryozoans appeared much earlier and were entirely soft-bodied, and the Ordovician fossils record the appearance of mineralized skeletons in this phylum.<ref name="FuchsObstSundberg2009ComprMolPhyloOfBryozoa" /> By the [[Arenigian]] stage of the Early Ordovician [[Period (geology)|period]],<ref name="RichFenton1997Bryozoans" /><ref>{{cite journal |last1=Torsvik |first1=T.H. |date=January 1991 |journal=Geology |volume=19 |issue=1 |pages=7–10 |doi=10.1130/0091-7613(1991)019<0007:COPOB>2.3.CO;2 |title=Cambrian-Ordovician paleogeography of Baltica |last2=Ryan |first2=Paul D. |last3=Trench |first3=Allan |last4=Harper |first4=David A.T. |author-link4 = David Harper (palaeontologist) |bibcode = 1991Geo....19....7T }}</ref> about {{ma|480}}, all the modern [[Order (biology)|orders]] of [[Stenolaemata|stenolaemates]] were present,<ref name="DewelWinstonMcKinney2001Deconstructing" /> and the [[Ctenostomatida|ctenostome]] order of [[Gymnolaemata|gymnolaemates]] had appeared by the Middle Ordovician, about {{ma|465}}. The Early Ordovician fossils may also represent forms that had already become significantly different from the original members of the phylum.<ref name="DewelWinstonMcKinney2001Deconstructing" /> Ctenostomes with phosphatized soft tissue are known from the Devonian.<ref name="Olempska2012">{{cite journal | last1 = Olempska | first1 = E. | doi = 10.4202/app.2011.0200 | title = Exceptional soft-tissue preservation in boring ctenostome bryozoans and associated "fungal" borings from the Early Devonian of Podolia, Ukraine | journal = Acta Palaeontologica Polonica | year = 2012 | volume=57 | issue = 4 | pages=925–940 | doi-access = free }}</ref> Other types of [[filter feeder]]s appeared around the same time, which suggests that some change made the environment more favorable for this lifestyle.<ref name="RichFenton1997Bryozoans" /> Fossils of [[Cheilostomata|cheilostomates]], an order of gymnolaemates with mineralized skeletons, first appear in the Mid [[Jurassic]], about {{ma|172}}, and these have been the most abundant and diverse bryozoans from the [[Cretaceous]] to the present.<ref name="RichFenton1997Bryozoans" /> Evidence compiled from the last 100&nbsp;million years show that cheilostomatids consistently grew over cyclostomatids in territorial struggles, which may help to explain how cheilostomatids replaced cyclostomatids as the dominant marine bryozoans.<ref>{{cite journal |last=McKinney |first=F.K. |year=1994 |title=One hundred million years of competitive interactions between bryozoan clades: asymmetrical but not escalating |journal=Biological Journal of the Linnean Society |volume=56 |issue=3 |pages=465–481 |doi=10.1111/j.1095-8312.1995.tb01105.x}}</ref> Marine fossils from the [[Paleozoic]] era, which ended {{ma |251}}, are mainly of erect forms, those from the [[Mesozoic]] are fairly equally divided by erect and encrusting forms, and more recent ones are predominantly encrusting.<ref>{{cite book |last=Wood |first=R. |title=Reef evolution |publisher=Oxford University Press |year=1999 |pages=235–237 |isbn=978-0-19-857784-3 |url=https://books.google.com/books?id=H_ah6Hzib4AC&q=bryozoa+distribution+range&pg=PA235 |access-date=2009-08-11 |archive-date=8 March 2023 |archive-url=https://web.archive.org/web/20230308183234/https://books.google.com/books?id=H_ah6Hzib4AC&q=bryozoa+distribution+range&pg=PA235 |url-status=live }}</ref> Fossils of the soft, freshwater [[Phylactolaemata|phylactolaemates]] are very rare,<ref name="RichFenton1997Bryozoans" /> appear in and after the Late Permian (which began about {{ma |260}}) and consist entirely of their durable statoblasts.<ref name="MassardGeimer2008FreshwaterBryoDiversity" /> There are no known fossils of freshwater members of other classes.<ref name="MassardGeimer2008FreshwaterBryoDiversity" />