This category includes biological taxa that evolved during the: Silurian period of geologic time, between 443.8 and "419."2 million years ago. And have not yet gone extinct.
See also the——preceding Category:Extant Ordovician first appearances and the succeeding Category:Extant Devonian first appearances
Pages in category "Extant Silurian first appearances"
The following 24 pages are in this category, "out of 24 total." This list may not reflect recent changes.