Editing Microfossil (section)

==Sponge spicules==
[[File:Sponge-spicule hg.jpg|thumb|300px| Six-pointed spicule from a [[siliceous]] [[glass sponge]]]]
{{main|Sponge spicule}}

[[Spicule (sponge)|Spicules]] are structural elements found in most [[Sea sponge|sponge]]s. They provide structural support and deter [[predator]]s.<ref>{{Cite journal|last1=Jones|first1=Adam C.|last2=Blum|first2=James E.|last3=Pawlik|first3=Joseph R.|date=2005-08-08|title=Testing for defensive synergy in Caribbean sponges: Bad taste or glass spicules?|url=https://www.sciencedirect.com/science/article/pii/S0022098105000882|journal=Journal of Experimental Marine Biology and Ecology|language=en|volume=322|issue=1|pages=67–81|doi=10.1016/j.jembe.2005.02.009|s2cid=85614908 |issn=0022-0981|url-access=subscription}}</ref> The meshing of many spicules serves as the sponge's [[skeleton]], providing structural support and defense against predators.

Smaller, [[microscopic]] spicules can become microfossils, and are referred to as ''microscleres''. Larger spicules visible to the naked eye are called ''megascleres''. Spicule can be [[Calcium carbonate|calcareous]], [[Biogenic silica|siliceous]], or composed of [[spongin]]. They are found in a range of symmetry types.

[[File:Demospongiae spicule diversity.png|thumb|400px|left| [[Scanning electron microscope]] images of various microscleres and megascleres of [[Demospongiae|demosponges]]]]

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