Life on land

We're pretty sure that life began in the oceans, and that the major milestones we looked at in the first lecture of this course occurred in water. Thus life on land represents a series of invasions of this new habitat from marine and/or freshwater organisms. This series of videos provides an overview of how and when this has occurred.


Our line up for this session is:

  • Terrestrial ecosystems – Section 1.
  • Adaptations to life on land – Section 2.
  • Precambrian life on land – Section 3.
  • Plants move onto land – Section 4.
  • Arthropods move onto land – Section 5.
  • Vertebrates move onto land – Section 6.
  • Life on land since the Mesozoic – Section 7.

I would be lying to you if I didn't admit that part of the reason terrestrialisation features on these websites is because I think it's super cool, and wanted to tell you all about it. And it's bad to lie. So I didn't. But it is also a vital topic in its own right. The majority of known species are of land animals. The majority of our crops are grown on land. We evolved on land. For all these reasons, and more, this is – like all the other topics I've covered – important stuff. Let's go!

1 – Terrestrial ecosystems

Cool. Let's jump right in. How exactly do we define life on land? Why does it matter, and what groups live on land?


  • For our purposes, we may want to consider freshwater ecosystems as terrestrial as well as dry land.
  • Multicellular eukaryotes moved onto land during the phanerozoic. Today we'll be looking at some major groups, in the order they made it onto land, namely:
    • Plants!
    • Arthropods!
    • Vertebrates!
  • There is a great diversity of life on land – potentially because there are so many niches in land environments.

So, we're thinking about land animals. Obviously, there is no better way to get thinking about them than doing a quiz!

2 – Adaptations to life on land

Air is different to water, in many ways. Just as we cannot breathe underwater, aquatic animals struggle to breathe air. Dealing with this change in respiration is just one of a suite of adaptations to life on land. We look at these adaptations in the next video.


Amongst the suite of adaptations to life on land across eukaryote groups, we see changes allowing organisms to:

  • Minimise water loss
  • Deal with increased gravity / lack of buoyancy
  • Present damage from UV light
  • Reproduce in the absence of water
  • Breathe air

3 – Precambrian life on land

Many books will tell you that all life on land originates in the last 500 million years. But that isn't strictly true.


  • There hasn't always been land exposed to the air. We believe this probably appeared by 3.2 Ga, and was definitely present by 2.5 Ga
  • We have evidence for life on periodically exposed bacterial mats from 1.0 Ga (Torridonian rocks, NW Scotland)
  • And in lacustrine/fluvial ecosystems at around the same time (Nonesuch Shale, Mi/Wi USA)

4 – Plants move onto land

The first macroscopic organisms on land (that we know of) were plants (FWIW, I suspect fungi were around on land at this time too). Lets learn about the early fossil record of plants!


  • The earliest evidence for complex plant life on land is found in the form of spores in the Ordovician
  • Land plants started as small, non-vascular things like mosses
  • Vascular plants followed soon afterwards, during the Early Silurian
  • The oldest widely accepted land-plant body fossil is the ~425 Ma genus Cooksonia

5 – Arthropods move onto land

Arthropods may have been on land with – or even before (ask me in person...) – the first plants. But we pick them up in the fossil record shortly after Cooksonia.


  • Myriapods (the group including millipedes and centipedes) and arachnids were on land by the Silurian
  • Many of the problems we have working out the tree of life of the arthropods are down to convergent evolution based on living on land
  • Our insights into early life on land are very much defined by a few important Lagerstätte
  • Forest ecosystems appear by 380 Ma; rooting systems then radically change continental sedimentary systems

6 – And vertebrates move onto land

Late to the life on land game, coming in almost last of major groups, are the vertebrates!


  • Vertebrates moved on to land in the Devonian between 385 and 375 Ma, evolving within the lungfish
  • The split between true amphibians (Lissamphibia: frogs, caecilians and salamanders) and amniotes (mammals and sauropsids, the latter being reptiles + birds) may have occurred in the Late Devonian
  • Certainly, the first amniotes – small- to medium-sized insectivores – were around in the Carboniferous coal forests
  • The insects (the first animals to fly) had also taken to the skies by this point

7 – From the Mesozoic to today

So all the lineages to venture out of the oceans that we have the time to cover in this lecture are now on land. But that doesn't mean that our story ends here. Let's look at how life on land has evolved since the Palaeozoic.


  • Post PT extinction, we see increasingly modern fauna and flora on land appear
  • In the Mesozoic, diapsids were more diverse, and then since the K-Pg, synapsids have become dominant
  • Major changes in land ecosystems occurred with the coevolution of flowering plants and insects, and with the advent of grasses
  • With the aid of genomic (i.e. DNA-based studies) we're also starting to get new insights into the origin of our own species

Bonus stuff!

You made it! Welcome to this site's bonus materials.

Want to learn more about plant origins?

Then we have you covered! The webpage linked below provides a wealth of really interesting detail, with lots of insights from fossils, on plant origins:

Digital Atlas of Ancient Life - Origin of Land Plants.

Want to learn more about human evolution?

We are very lucky at the University of Manchester that for three years we had a world expert in human evolution working with us – Dr Marta Pina Miguel. Dr Pina Miguel was a Marie Skłodowska-Curie Fellow in the University, an Associate Researcher at the ICP Miquel Crusafont (Spain), and a world expert in the evolution of the primate postcranium and the origin of the positional behaviors observed in living apes and humans.

She has kindly put together a short overview on the evolution of bipedalism! You can find this bonus (and exclusive!) content below: