The Discovery of Prehistoric Sea Creatures and the Age of Dinosaurs
The origins of a mysterious group of prehistoric sea creatures have recently been revealed to be much younger than previously thought. Researchers from Durham University, U.K., and Yunnan University and Guizhou University in China discovered that the fossilized remains of these creatures—formerly believed to be Bryozoans—are actually green algae.
The discovery of the oldest Ichthyosaur—an extinct group of marine reptiles whose fossils have been recovered worldwide—on the remote Arctic island of Spitsbergen has also caused scientists to revise their understanding of the Age of Dinosaurs. The 11 vertebrae and 15 bone fragments found on the island has led to the conclusion that Ichthyosaurs evolved earlier than previously thought, and may even have originated prior to the world’s worst mass extinction.
In 2021, experts found a convincing bryozoan fossil from the Cambrian period, of a species called Protomelission gatehousei. This discovery, published in Nature, suggested that bryozoans were not an oddity that cropped up later in time, as had previously been thought, but arose during the Cambrian explosion, like most other animal groups.
However, analyses of fossils even better preserved than those described previously have revealed that the species may not have been a bryozoan after all. Dr Martin Smith, a co-author of the paper from Durham University, says, “This fossil is clearly not a normal bryozoan, and we’ve opened other possibilities for what it might be.”
The findings mean Bryozoans—tentacle-bearing animals that lived in skyscraper-like underwater colonies—are millions of years younger than previously thought, only appearing in the Ordovician period (480 million years ago).
Close to the hunting cabins on the southern shore of Ice Fjord in western Spitsbergen, Flower’s valley cuts through snow-capped mountains, exposing rock layers that were once mud at the bottom of the sea around 250 million years ago. The swift river, nourished by melted snow, has worn away the mudstone, uncovering rounded limestone boulders known as concretions. Today, paleontologists search for concretions to investigate the remnants of ancient marine life.
0. “Oldest fossils of mysterious animal group are really seaweeds, study suggests” The Independent, 8 Mar. 2023, https://www.independent.co.uk/news/science/research-durham-university-china-b2296662.html
1. “Mysterious Fossils Thought To Be The Oldest Bryozoans Turn Out To Be Seaweeds” Revyuh, 8 Mar. 2023, https://www.revyuh.com/news/science-and-research/sustainability/mysterious-fossils-thought-to-be-the-oldest-bryozoans-turn-out-to-be-seaweeds/
2. “Early Ictyosaur Remains Has Been Discovered on the Remote Arctic Island of Spitsbergen” Nature World News, 14 Mar. 2023, https://www.natureworldnews.com/articles/55831/20230314/early-ictyosaur-remains-discovered-remote-arctic-island-spitsbergen.htm
3. “Fossils thought to be ancient marine creatures may be seaweed, study suggests” The Guardian, 9 Mar. 2023, https://www.theguardian.com/science/2023/mar/08/fossils-ancient-marine-creatures-may-be-later-seaweed-study
4. “Weird Lifeform From 500 Million Years Ago Wasn't an Animal at All” ScienceAlert, 9 Mar. 2023, https://www.sciencealert.com/weird-lifeform-from-500-million-years-ago-wasnt-an-animal-at-all
5. “Prehistoric ‘moss animals’ are millions of years younger than believed” The Jerusalem Post, 10 Mar. 2023, https://www.jpost.com/science/article-733975
6. “Oldest sea reptile from Age of Dinosaurs found on Arctic island” Phys.org, 13 Mar. 2023, https://phys.org/news/2023-03-oldest-sea-reptile-age-dinosaurs.html