Cryptolithus

{{Short description|Extinct genus of trilobites}}

{{Distinguish|Cryptolithodes}}

{{Automatic taxobox

| fossil_range = {{fossil range|Ordovician}}

| image = Cryptolithus NMNH.jpg

| image_caption = Cryptolithus fossil, National Museum of Natural History

| image2 = Raymond 1920 f20.png

| image2_caption = Reconstruction of the ventral side of Cryptolithus tessellatus

| taxon = Cryptolithus

| authority = Green, 1832{{cite journal|url=https://archive.org/stream/monographoftrilo00greerich#page/72/mode/2up|title=A Monograph of the Trilobites of North America: With Coloured Models of the Species|first=Jacob|last=Green|date=1832|volume=1|publisher=Joseph Brano|pages=72–78|doi=10.5962/bhl.title.66801|doi-access=free}}

}}

Cryptolithus is a genus of extinct epifaunal, suspension-feeding, trinucleid trilobites that lived during the Ordovician period.{{Cite encyclopedia|title=Cryptolithus|date=6 August 2019|access-date=7 December 2020|encyclopedia=Encyclopædia Britannica|url=https://www.britannica.com/animal/Cryptolithus}} They were mostly blind.{{Cite web |url=https://www.ordovicianatlas.org/atlas/arthropoda/trilobita/asaphida/trinucleidae/cryptolithus/ |title=Cryptolithus |last=Stigall |first=A.L. |website=Atlas of Ordovician Life|date=12 November 2013 }} They are found in the United States, Canada, Venezuela, the United Kingdom, France, the Czech Republic, Morocco and Turkey.{{Cite web |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=19920 |title=†Cryptolithus Green 1832 (trilobite) |website=fossilworks |access-date=17 December 2021}}