Rangeomorphs are believed to be some of the earliest animals on earth. Unicellular life is believed to have existed for more than 3 billion years, but rangeomorphs are among the earliest complex animals. They lived in oceans approximately 575 million years ago. Their size ranged from 10 cm up to 2 meters tall, making them the largest organisms at the time.
Cambridge University researchers worked on devising a new model representing the earliest animals called Rangeomorphs. The animals lived during the Ediacaran period which lasted from 635 million to 541 million years ago).
We are getting a more and more precise image of how life forms evolved throughout history. Recently we covered another story about how dinosaurs gradually shrank to evolve into birds.
Rangeomorphs appear to have looked like plants. They were composed out of soft branches getting smaller diminishing toward the top in a fractal geometrical shape. Despite that, rangeomorphs were animals.
“We know that rangeomorphs lived too deep in the ocean for them to get their energy through photosynthesis as plants do,” said Dr Jennifer Hoyal Cuthill of Cambridge’s Department of Earth Sciences, who led the research. “It’s more likely that they absorbed nutrients directly from the sea water through the surface of their body. It would be difficult in the modern world for such large animals to survive only on dissolved nutrients.”
The earliest animals called Rangeomorphs were not equipped to face competition
The stationary animals were among the largest creatures in the sea, being surrounded by much simpler life forms. Fortunately, there are many well preserved rangeomorph fossils around the world. The animals were feeding on the dissolved carbon and the particular geometrical shape allowed them to absorb nutrients efficiently.
Scientists believe that rangeomorphs are so unique that they deserve to be classified as a separate clade, a separate evolutionary branch.
The special animals survived for millions of years. Their environment changed along with the Cambrian explosion, which started about 541 million years ago. The change entailed a massive transformation of life forms. Some of the first animal groups emerge back then. It meant that there was increased competition for nutrients. The earliest animals called Rangeomorphs were defenseless and could not survive the competition presented by new mobile creatures. Thus, they are unique in history.
The article “Fractal branching organizations of Ediacaran rangeomorph fronds reveal a lost Proterozoic body plan” appeared in PNAS journal.