A new study conducted more than 25 years ago on fossil material from the mountains of Utah has yielded further evidence of the tremendous complexity of ancient animal ecosystems. According to the research, the first animals on Earth formed complex ecological communities.
Some underwater samples of fossilized creatures exposed many sensitive structures resembling microscopic organisms, namely, fungi. This disclosure has permitted the investigators to reliably pinpoint this fossil as a Radiodonta, an extinct group of stem arthropods and distant cousins of present-day crabs, insects, and spiders. The study has been released in a report in Nature Communications.
“Our new study describes Pahvantia Hastasta, an extinct relative of modern arthropods, which feeds on microscopic organisms near the surface of the ocean,” explained Stephen Pates from the Oxford University’s Department of Zoology.
The first animals on Earth formed complex ecological communities
“We discovered that he used a fine mesh to capture much smaller plankton than any other known swimming animal of comparable size to the Cambrian period. That shows that large animals that swim freely helped drive the diversification of life at the bottom of the sea some five hundred million years ago,” Pates added.
The reasons for the Cambrian Explosion, the sudden appearance of a diverse animal fauna which according to the fossil record took place about 540 to 500 million years ago, is still the focus of intense controversy. While it probably involved a mixture of ecological and environmental considerations, the development of a system for shifting energy from the primary production area which was the surface ocean to the most diverse region, the seabed, had a vital function.
The research has yielded the most updated understanding of the evolutionary interactions between Radiodotas. It also illustrates that filter-feeding developed twice, perhaps three times over in this family of ancient animals, which would otherwise comprise essentially dreaded predators like the Anomalocaris Canadensis of Burgess Shale in Canada. The investigation shows that the first animals on Earth formed complex ecological communities, as well.