Scientists have discovered fossil evidence that higher invertebrates, particularly irregular sea urchins and sea urchins, have stably colonized the deep ocean for at least 104 million years since the Cretaceous period. Analyzing more than 40,000 vertebral fragments taken from sediment samples, the research team found evolutionary changes over time, especially after large-scale extinction events, and found that future global warming may affect deep-sea ecosystems. suggested a potential impact on
A research team led by the University of Göttingen has reported on the early occurrence of irregular sea urchins in the deep sea.
Deep in the depths of the ocean, Earth’s earliest and most primitive life forms are thought to have emerged long ago. Today, the deep sea is known for its strange fauna.How do researchers seed The diversity of the ocean floor has evolved over time.
There is a hypothesis that suggests that deep-sea ecosystems have been repeatedly reincarnated through numerous mass extinctions and ocean disturbances. Therefore, modern marine life at these depths may be relatively recent on Earth’s timeline. However, growing evidence suggests that this portion of the underwater realm may be older than once assumed.
A research team led by the University of Göttingen has provided the first fossil evidence of stable colonization of the deep ocean by higher organisms. invertebrate At least 104 million years. Fossilized irregular sea urchin spines indicate that sea urchins have existed for many years since the Epoch Epoch. Cretaceous period As well as evolution under the influence of changing environmental conditions, the results were published in the journal Pro Swan.
![Different sea urchin spines from different periods of Earth's history showing diversity in shape](https://scitechdaily.com/images/A-Range-of-Sea-Urchin-Spines-From-Different-Periods-of-the-Earths-History-Illustrating-the-Diversity-of-Shapes-647x1024.jpg 647w,https://scitechdaily.com/images/A-Range-of-Sea-Urchin-Spines-From-Different-Periods-of-the-Earths-History-Illustrating-the-Diversity-of-Shapes-253x400.jpg 253w,https://scitechdaily.com/images/A-Range-of-Sea-Urchin-Spines-From-Different-Periods-of-the-Earths-History-Illustrating-the-Diversity-of-Shapes-768x1215.jpg 768w,https://scitechdaily.com/images/A-Range-of-Sea-Urchin-Spines-From-Different-Periods-of-the-Earths-History-Illustrating-the-Diversity-of-Shapes.jpg 942w)
Various sea urchin spines from different eras of Earth’s history. Variety of shapes is shown. Credit: PLOS ONE, 2023 Wiese et al.
The researchers examined more than 1,400 sediment samples taken from boreholes representing former depths of 200 to 4,700 meters in the Pacific, Atlantic, and Southern Oceans. They found more than 40,000 spine fragments and classified them into groups called irregular spinous processes based on their structure and shape.
For comparison, the scientists recorded morphological characteristics such as spine shape and length, and measured the thickness of about 170 vertebrae from each of the two time periods. They measured the amount of spiny material in the sediment as an indicator of the total mass, or biomass, of sea urchins in their habitat.
These fossilized spines record that irregular nepenthes have lived continuously in the deep sea since at least the early Cretaceous period, about 104 million years ago. And they offer even more exciting insights into the past. A catastrophic meteorite impact at the end of the Cretaceous period, about 66 million years ago, caused a worldwide mass extinction, with dinosaurs being the most notable victims, but also caused considerable global disruption. caused it. Deep sea.
This is indicated by morphological changes in the spine. After the event, the vertebrae became thinner and less diverse in shape than before. Researchers interpret this as the “Lilliput effect.” This means that smaller species have a survival advantage after mass extinctions, leading to smaller species body sizes. The cause may have been a lack of food at the bottom of the deep sea.
“We interpret the changes in the spines as an indication of the continuous evolution and emergence of new species in the deep sea,” explains the study’s lead author, Dr. Frank Wiese from the Department of Geobiology at the University of Göttingen. . He highlights another finding. “About 70 million years ago, the biomass of sea urchins increased. At the same time, the water also became colder. This relationship between deep-sea biomass and water temperature shows how anthropogenic global warming has affected the deep sea. We can speculate on whether that will change.”
Reference: “A 1.04 million-year record of deep-sea atherostomata (Holasterioda, Spathangoida, irregular echinoids) – persistence, food availability, and the Big Bang story” by Frank Wiese, Nils Schlüter, Jessica Zirkel, Jens O. Friedrich by Herle, Oliver, August 9, 2023. Pro Swan.
DOI: 10.1371/journal.pone.0288046
In addition to the University of Göttingen, the research project also involved the University of Heidelberg, the University of Frankfurt and the Berlin Museum of Nature.