It is hard to believe that any species existed on Earth, even before dinosaurs. But, there were many types of flora and fauna inhabiting the Earth even before dinosaurs came into the scene. Those organisms are considered to be the ancestors of dinosaurs and many other animals. But in general, what was before dinosaurs that lived on Earth? And why did the Paleozoic Era end in one of the largest mass extinctions faced on Earth?
1. Permian Age
To answer what was before Dinosaurs, you should know about the age which comes before their existence. The age before the dinosaurs started 298.9 million years ago and lasted till 252.2 million years from today.
- The starting period was known as the Carboniferous period, and the outset was known as the Triassic Period.
- This period is known as the Permian Age, and it ended 6 million years before the dinosaurs came into existence. This era is considered the last period of the Paleozoic Era.
- During this period, all the continents were joined with each other as a large mass of land. There were no water bodies in between them to separate them. Scientists later named this supercontinent Pangaea. This was surrounded by an immense world ocean called Panthalassa. It was during the late Paleozoic Era and early Mesozoic Era.
Then, it started to break and took the shape of different continents. (See Are Dinosaurs Alive? )
2. Species lived during Permian Age
Although the age of reptiles or the age of dinosaurs started much later than this age, this era is still known to have some early dinosaurs and reptile ancestors.
- The species dominating this era were small Trilobite, which was mollusks like organisms living in water bodies.
- Woodlouse and armadillo can be taken as examples of the average-sized animals that lived during this era.
- The lobe-finned, spiny fishes, arthropods, and amphibians were also very common during this age.
- Insects also resided on Earth even for millions of years. Ancestors of cicadas, dragonflies, and beetles lived during this era. (Also read 25 Types of Dinosaurs)
3. Environment and Habitat
Since the age started after the Paleozoic era, there were still ice and huge icebergs around during the cold winters. It was very dry over much of Pangaea during the summer. Slowly and eventually, with the ice melting, the temperature started to increase above the freezing point.
- All the species of animals did not start flourishing at the start of the Permian age. Some became extinct because of the sudden temperature shift, while others took millions of years to develop and adapt to the new environment.
- What was before dinosaurs were actually many animals that thrived and ruled the continent were, including Edaphosaurus, Dimetrodon, and other pelycosaurs like Eryops, Diplocaulus, archosaurs, amphibians, fish, and lots of invertebrates like insects, worms, etc.
- As the era ended, there were no more ice caps remaining, and the temperature was almost the same throughout the Earth. This proved to be a beneficial factor for the herbivores living in that time as they could have access to a large area for food. Pelycosaurs were succeeded by Therapsids which looked like mammals. (See Oldest Living Species Alive Today)
4. Causes of Great Dying
Permian–Triassic extinction event, also known as the Great Dying, formed the boundary between the Permian and Triassic geologic periods.
- It is believed that this event released 1 million times more of the energy which caused the volcanic activity in the volcanoes in Siberia. The massive volcanic eruptions led to huge lava overflow and smoke accumulation, which could have led to the depletion of oxygen levels on land and water bodies.
- Scientists at the universities of Washington and Rochester, United States, have discovered traces of helium and argon gas molecules. They were trapped in the rocks, which are as old as the Permian Age. Since today the exact cause is still unknown but the increase in overall temperature was definitely one of the most important reasons leading to The Great Dying. And what was before dinosaurs, including flora and fauna, almost everything was wiped out due to this event.
5. Extent of Extinction
In one of the most massive extinctions faced by Earth, more than 95 percent of marine species and more than 70 percent of land species of animals were wiped out. The flora, as well as fauna, was affected adversely. From the fossils derived from the Italian Alps, it became clear that before the extinction, coniferous trees were covering the region. And after this extinction, when the new era started, there were very few traces of trees. (See Why Did the Archaeopteryx Become Extinct?)
6. Survivors of Mass Extinction
After understanding What are mass extinctions, and what causes them? let’s read about the survivors.
- Fungi are most commonly found from the shreds of evidence and fossils. It is believed that they developed after the trees were destroyed during the extinction.
- Therapsids survived this extinction and ruled the Earth after that era. They were mammal-like reptiles. And the other species that survived were archosaurs, which looked more like reptiles compared to therapsids.
- However, as time advanced, the therapsids became extinct, and the archosaurs took over, giving rise to the age of dinosaurs. The plants and animal species that were before dinosaurs remained only about 10%–20 % and led to the beginning of the dinosaurs’ era.
7. Discovered Fossils and Fossil Reptiles
During and after the Triassic Period, many fossils were found. What was before dinosaurs are shown through fossils evidence about the presence of whiskers, which indicates that there must be fur-bearing animals also in this age. Read our article on the Interesting History of Dino Bones to know more!