Editing Hexactinellid (section)

{{short description|Class of sponges with siliceous spicules}}
{{Automatic taxobox
| name = Glass sponges
| fossil_range = Late [[Ediacaran]]–present{{fossil range|544|0|<ref name="Brasier1997">{{cite journal | last1 = Brasier | first1 = Martin | last2 = Green | first2 = Owen | last3 = Shields | first3 = Graham | date = April 1997 | title = Ediacarian sponge spicule clusters from southwestern Mongolia and the origins of the Cambrian fauna |url=https://www.researchgate.net/publication/240669632 |format=PDF | journal = Geology | volume = 25 | issue = 4 | pages = 303–306 | doi = 10.1130/0091-7613(1997)025<0303:ESSCFS>2.3.CO;2 | bibcode = 1997Geo....25..303B }}</ref>}}
| image = Haeckel Hexactinellae.jpg
| image_caption = "Hexactinellae" from [[Ernst Haeckel]]'s ''[[Kunstformen der Natur]]'', 1904
| taxon = Hexactinellida
| authority = Schmidt, 1870
| subdivision_ranks = Subgroups
| subdivision = [[#Classification|See text]].
| synonyms = * Hyalospongiae
}}
[[File:Bolosoma stalked glass sponge (39506105791).jpg|thumb|Bolosoma stalked glass sponge]]
'''Hexactinellid sponges''' are [[sponge]]s with a [[skeleton]] made of four- and/or six-pointed [[silica|siliceous]] [[spicule (sponge)|spicule]]s, often referred to as '''glass sponges'''. They are usually [[biological classification|classified]] along with other sponges in the [[phylum]] [[Porifera]], but some researchers consider them sufficiently distinct to deserve their own phylum, '''Symplasma'''. Some experts believe glass sponges are the longest-lived animals on earth;<ref>{{Cite web |title=Hexactinellid sponge (Scolymastra joubini) longevity, ageing, and life history |url=https://genomics.senescence.info/species/entry.php?species=Scolymastra_joubini |access-date=2 March 2023 |website=genomics.senescence.info}}</ref> these scientists tentatively estimate a maximum age of up to 15,000 years.