Editing Radula (section)

==Early mollusks==
The first ''bona fide'' radula dates to the [[Early Cambrian]],<ref name=Butterfield2008>{{Cite journal | last = Butterfield | first =  N.J. | year = 2008 | title = An early Cambrian radula | journal = Journal of Paleontology | issue = 3 | pages = 543–554 | doi = 10.1666/07-066.1 | volume = 82| bibcode = 2008JPal...82..543B | s2cid = 86083492 }}</ref> although trace fossils from the earlier [[Ediacaran]] have been suggested to have been made by the radula of the organism ''[[Kimberella]]''.

A so-called radula from the early Cambrian was discovered in 1974, this one preserved with fragments of the mineral [[ilmenite]] suspended in a [[quartz]] matrix, and showing similarities to the radula of the modern cephalopod ''[[Sepia (genus)|Sepia]]''.<ref name=Firby1974>{{Cite journal| issue = 6| volume = 48| pages = 1109–1338 | last1 = Firby| issn = 0022-3360| journal = Journal of Paleontology| title = Molluscan Radula from Earliest Cambrian| date = 1 November 1974| first1 = J. B.| last2 = Durham| first2 = J. W.}}</ref> However, this was since re-interpreted as ''[[Salterella]]''.<ref>{{Cite journal| first1 = E. L.| first2 = G. N.| title = Early Cambrian Salterella and Volborthella (Phylum Agmata) re-evaluated| last1 = Yochelson| journal = Lethaia| volume = 36| issue = 1| pages = 8–20| year = 2003| doi = 10.1080/00241160310001254| last2 =  Kisselev| bibcode = 2003Letha..36....8Y}}</ref> [/''[[Volborthella]]''?]{{Verify source|date=March 2009}}

Based on the bipartite nature of the radular dentition pattern in solenogasters, larval gastropods and larval polyplacophora, it has been postulated that the ancestral mollusk bore a bipartite radula (although the radular membrane may not have been bipartite).<ref name="Scheltema2003a"/>