Editing Trilobite (section)

====Final extinction====
At the end of the Permian ([[Changhsingian]]), only two genera of trilobites remained extant, ''[[Acropyge]]'' and ''Pseudophillipsia.<ref name=":2" />'' [[Late Permian]] trilobites primarily occurred in shallow marine [[carbonate platform]] environments, but were also found in deep water, and were widespread, ranging towards the poles.<ref name=":2" /> 

Exactly why the trilobites became extinct is not clear; with repeated extinction events (often followed by apparent recovery) throughout the trilobite fossil record, a combination of causes is likely. After the extinction event at the end of the Devonian period, what trilobite diversity remained was bottlenecked into the order Proetida. Decreasing diversity<ref name="Owens03">
{{Citation |last1=Owens |first1=R. M. |contribution=The stratigraphical distribution and extinctions of Permian trilobites. |editor=Lane, P. D. |editor2=Siveter, D. J. |editor3=Fortey R. A. |series=Special Papers in Palaeontology|volume= 70 |title=Trilobites and Their Relatives: Contributions from the Third International Conference, Oxford 2001 |pages=377–397 |publisher=Blackwell Publishing & Palaeontological Association |year=2003}}</ref> of genera limited to shallow-water shelf habitats coupled with a drastic lowering of sea level ([[Marine regression|regression]]) meant that the final decline of trilobites happened shortly before the [[Permian–Triassic extinction event|end Permian mass extinction event]].<ref name="Fortey&Owens97a" /> With so many marine species involved in the Permian extinction, the end of nearly 300{{nbsp}}million successful years for the trilobites would not have been unexpected at the time.<ref name="Owens03" />