Thrombolites

After our Rottnest Island adventure, we headed south to Busselton. During our way, we came across Yalgorup National Park and met the earliest living organisms on earth. No, I don’t mean Jurassic Park. That’s not distant or early enough. We’re talking here about thrombolites of Lake Clifton.

At first glance, the muddy or rocklike humps look a bit lackadaisical. If you dig out their history, they are the only known form of life on this planet somewhere 650 million years ago. At that time, there was no oxygen in the atmosphere. Next came colonies of prokaryotic cyanobacteria which were able to carry out photosynthesis. That was the key to jack up the oxygen content in the primeval earth’s atmosphere. Thrombolites, as it turns out, are fossil record of these earliest living organisms on earth.

Now that our oceanic oxygen levels had fallen by 2% in 50 years, thrombolites remind us what we badly need.