You can give a numeric range, or specify the periods involved. The range will be quoted in text before the timeline, unless you specify a third parameter—leaving it blank will result in no text being provided.

To illustrate the range when it spans before the Ediacaran (i.e. deep into the Precambrian), you should use Template:Long fossil range, which works in exactly the same way as documented here.

You can also specify "earliest" and "latest" to add a "ghost" bar beyond the accepted fossil range. You can use these parameters for whatever you like; they may be useful in the case of living fossils such as the coelacanth, where you may wish to specify latest=0 to make the bar faintly extend to the present; they may also be useful where "earliest" fossils are not universally accepted—for instance, the octocorals only have a good fossil record from the Ordovician, but there are claims of Cambrian representatives. In this case, you may wish to specify earliest=late Cambrian.

{{Geological range|Permian}}

{{Geological range|Permian|Jurassic}}

{{Geological range|Permian|Jurassic|earliest=Devonian|latest=Cretaceous}}

{{Geological range|68|65|earliest=Permian|latest=0|PS= (see article for discussion)}}

{{Geological range|68|65.5|late Cretaceous}}

{{Geological range|68|65|}}

If you receive an error when specifying a period name, check you've spelt it right; if so, it probably isn't yet incorporated into the templates {{next period}} and {{period start}}. The pages are template protected due to their high use, but feel free to add an edit request on their talk pages to make future editors' lives easier!

For organisms whose fossil range extends significantly before the Ediacaran, use Template:Long fossil range.

• Template:Geological range/linked