Photo by zhang kaiyv
During the Carboniferous Period, terrific plants that flourished millions of years ago, allowing life on land to explode in population.
Geologist and author Thomas F. Mcloughlin are one of the people studying plant fossils of the central Appalachian coalfields. They aim to understand better the role of these ancient plants and how they helped shape our world. It’s truly an important task that uncovers the secrets of our past a bit more.
Throughout their research, they have discovered many ancient plant species. Ancient plants were responsible for bringing an essential ecological change. We’ll be looking at some of those plants to get a better look at what the first forests possibly looked like!
The Early Settlers That Covered Earth
Green algae in shallow coastal waters evolved some 500 million years ago to benefit from the neighboring dry soil. The early settlers had two main challenges to overcome: the requirement to sustain their bodies and the risk of drying out.
There were different strategies that these plants applied. Some terrestrial plants (hornworts, mosses, and liverworts) evolved to survive periods of drought; they remained reliant on water. Others addressed these difficulties by creating roots that anchor them. They also developed a waxy covering to stop water loss and vascular tissues that carry water and offer structural support.
As the years passed, many adaptations regarding the form and framework of plants for terrestrial life occurred. These features were created and refined over tens of millions of years, as fossils like Aglaophyton and Cooksonia demonstrated.
Starting Small with the Sprouting Giants
Although Psilophyton could grow to tens of centimeters, most early Devonian plants (420-390 million years ago) were only a few centimeters tall. Tree-like (“arborescent”) plants began to appear in the fossil record around the mid-Devonian (about 390 million years ago), and they gradually became the most dominant plant through the Carboniferous (360–300 million years ago).
Plant fossils of the central Appalachian coalfields also revealed that these impressive plants that flourished millions of years ago and raised oxygen levels. Although coal is also found in beds from other geological eras, the Carboniferous (carbo= “coal” + ferre= “to carry”) was the name given to these early forests, which is now a rich source of the coal that powers our environmentally negligent civilization.
Carboniferous forests comprised ferns, lycopsids (club mosses), and sphenopsids (horse tails). Early seed plants and Progymnosperms first arose in tropical latitudes during the mid-to-late Carboniferous. At this moment, ferns replaced lycopsids and sphenopsids as the most common forest plants.
The Earliest Trees That Towered Above Others
Wattieza and Archaeopteris are the first trees identified in the fossil record, different from the similarly pronounced Archaeopteryx. A progymnosperm, or a group of trees similar to modern gymnosperms but proliferated through spores instead of seeds, Archaeopteris was around 10 meters tall.
Gymnosperms that are alive today are thought to have their origins in Archaeopteris. It featured a woody stem covered in huge fronds and annual growth rings that showed how thick the stem got throughout its life. Similar to gymnosperms, it donned an extensive root system.
But unlike gymnosperms, Archaeopteris also proliferated using spores borne on unique leaves, which is identical to what modern ferns do.
When Colossal Plants Reached for the Heavens
The arborescent lycopsids (also known as “giant club mosses”), which include Lepidodendron and Sigillaria, began to emerge in the dense forests of the late Devonian and early Carboniferous. A root of the lepidodendron, which could reach a height of 35 meters, was composed of many branching axes with stigmaria, or spirally organized rhizoids.
The bark was green because it was actively photosynthesizing and had a characteristic structure of diamond-shaped scarring from the leaf bases. Despite their size, these ancient forests seemed utterly different to modern eyes. The Devonian and Carboniferous were warm, moist, and carbon dioxide-rich eras.
However, the climate eventually became drier and cooler. Glaciers began to form and spread over southern Gondwana, and the first forests eventually perished. Indeed, good things do not last. But the Carboniferous Period and the plants that flourished millions of years ago in it will never be forgotten.
If you wish to learn more, particularly about the plant fossils of the central Appalachian coalfields, purchase A Guide to Pennsylvanian (Carboniferous) Age Plant Fossils of Southwest Virginia by Thomas F. Mcloughlin today!