Ancient Bacteria First to Colonize Land over 407 Million Years Ago

Researchers have made a significant discovery about the colonization of land by ancient species of bacteria. A team of paleobiologists at the National History Museum in the UK have found that an ancient species of bacteria called Langiella scourfieldii was among the first to live on land over 407 million years ago.

L. scourfieldii belongs to the cyanobacteria family, specifically the Hapalosiphonaceae family. These microorganisms grew alongside early land plants in the Early Devonian period.

Although cyanobacteria have been studied by scientists for a long time, there is much that is still unknown about how these photosynthesizing organisms managed to transition from water to land. The recent research conducted by Dr. Christine Strullu-Derrien and her team has filled in some of these knowledge gaps. They discovered that L. scourfieldii is the oldest species of cyanobacteria known to have lived on land, providing valuable insight into the early colonization of land.

Cyanobacteria are among the oldest fossils ever discovered, with some dating back around 2 billion years. These bacteria, also known as blue-green algae, thrive in various water environments such as oceans, rivers, and damp rocks.

Cyanobacteria play a crucial role in shaping the planet and its history. Through photosynthesis, they helped create the oxygen we need to survive. This process initiated the Great Oxygenation Event, which occurred around 2.4 to 2.1 billion years ago. The event led to the replacement of methane with oxygen as the main component of the atmosphere, resulting in a mass extinction for anaerobic organisms.

L. scourfieldii were first discovered in 1959 at the Rhynie Chert fossil site in Scotland. However, recent samples from the same area were more suitable for analysis, allowing scientists to observe evidence of “true branching,” which is characteristic of Hapalosiphonacean cyanobacteria. This finding confirms that L. scourfieldii existed in damp land ecosystems and successfully made the transition from water to land during the Early Devonian period.

The Rhynie Chert fossil site provides a unique glimpse into the past, as it preserves traces of different organisms that coexisted 400 million years ago. During this time, the landscape of Scotland would have been much different than it is today, with a warmer tropical climate. Microbial mats formed by fungi, bacteria, and algae played a crucial role in supporting the growth of early land plants with their shallow roots.

The study conducted by Dr. Christine Strullu-Derrien and her team has been published in iScience.

– iScience