Life across space... And time.

I find it kind of hard to fathom, but this is session #9. We're almost done! We have this, then one more session left. Before we finish, I wanted to introduce a rich area of research that incoporates fossils: their distribution. And by extension, this means the distributions of extinct species, in deep time. This is palaeobiogeography. It's super cool.

Introductory video


As before, building on your feedback, we'll have four videos, then some content for zoom! These are:

  • Introduction and history – Section 9.1.
  • Principles and provinces – Section 9.2.
  • Barriers, mixing and evolution – Section 9.3.
  • Iapetus – Section 9.4.
  • Patterns of biodiversity – Zoom.

9.1 – Introduction and history



  • Palaeobiogeography is the scientific study of the geographic distribution of fossils.
  • Biogeography (the study of the distribution of living species) has a surprisingly deep history with roots around the time of the Enlightenment.
  • Charles Darwin and Alfred Russel Wallace made key observations about the distribution of living species, and fossils were key to establishing continental drift.
  • Beware whiggism.

9.2 – Principles and provinces


  • Biogeography can describe distributions, and also try and explain these (interpretative biogeography) – the latter form can be historical or ecological.
  • Endemic is a term applied to a species or other taxonomic group that is restricted to a particular geographic region. A province is the association of multiple endemic species.
  • Cosmopolitan species are widespread, i.e. not endemic.
  • Provinces were present in the past, and can be seen in fossil assemblages back to the late Ediacaran.

Hey, it's time for a quiz. You know the score.

9.3 – Barriers, mixing and evolution

What defines provinces? What happens when provinces collide? What effect does this have on biodiversity? All this, and more... In video #3.


  • Biogeographic provinces are partitioned by barriers: these are often porous, and a barrier for one group of organisms may be a corridor for another.
  • When a barrier is removed, a biotic immigration event (BIME) can result.
  • Modelling suggests that repeated BIMEs can lead to increased biodiversity.
  • Vicariance is the process by which a barrier appears across a species range resulting in new species sharing a common ancestor.

9.4 – Iapetus

Let's dig into a real example and look at the picture fossils (and other approaches) provide of the birth, growth and then death, of an ocean over 300 million years ago.


  • The Iapetus ocean:
    • Developed in the Cambrian.
    • A series of conteinental collisions are recorded by the fossil fauna across North America, the UK, and Scandinavia.
    • The ocean shrank into the Devonian, before finally closing with the assembly of a large continent Laurussia.
  • Not all fossils are equally good for palaeobiogeographic analysis: knowledge of the precise age and lifestyles of organisms are really useful for palaeogeographic analyses.

Bonus stuff!

Very well done. You've made it to the end of session #9. Christmas is creeping up. Why not spend a little time learning more about palaeobiogeography.

The best kind of christmas present!

If you're interested in the kind of cutting edge analyses that researchers are using to understand the distribution of fossils, and how this interacts with a group's phylogeny, then search no further. This is a conference talk by my colleage Graeme Lloyd from a few years ago looking at the palaeobiogeography of dinosaurs:

It has dinosaurs! Trees! Computers! Biodiversity! It's super cool, and well worth your time, especially if your interests lie in the computational and palaeontological.


You can find an interesting and approachable overview of Whig History in the article linked below, on the Guardian website.

Why whiggish won't do.