Trilobite help?

Question

Does anyone know what trilobites are found in Scotland and England that prove that Scotland andEngland were once separate and joined to separate continents??

Answer 1

The early Cambrian trilobite "Callavia" is only found in England and Wales (& Europe / Gondwana), while the age-equivalent "Olenellus" is only found in Scotland (and America /Laurentia). At this time, both areas were separated by the Iapetus Ocean, which was possibly of similar magnitude to the Atlantic. The Iapetus Ocean had closed by the end of the Ordovician, at which points the two continents became fused along the so-called "Iapetus Suture" (a subduction zone the remains of which underly the Solway Firth).

Hope this helps!

Answer 2

The timing of the joining of Scotland and England sometime in the Ordovician is evidenced by a shift in the trilobite fauna.

Prior to the join, each region had a slightly different trilobite fauna, as they were separated by the Iapetus ocean. As the Iapetus closed and the plates joined together, the fauna became more and more the same.

I believe that the taxa that it is primarily used to illustrate this shift is the trilobite genus Paradoxides. I'm not sure about which species or what the exact differences in morphology are, however.