Source: Science and Technology Daily
The eastern part of Yunnan was once an ocean, home to a large number of tongue-shaped shell brachiopods. The picture shows a simulated map of tongue-shaped shell community 500 million years ago. Courtesy of respondents
New solution
Science and Technology Daily News (reporter Lu Chengkuan) In the biological world, parasitic phenomena are everywhere. Soon after the Cambrian explosion 540 million years ago, animals needed to fight the parasite. Researchers from Northwestern University and other domestic and foreign units have found that ancient brachiopods were parasitized by a biological organism that may be able to convert brachiopod food to self-food. This is the oldest parasitic relationship ever found in the fossil record. The research results were recently published online in the journal Nature Communications.
Brachiopods are small shelled marine invertebrates that have two hard shells, one end articulated and the other end open for feeding or closed to form protection. Brachiopods feed through a circle of ciliated tentacles (ciliary rings), which are usually arranged in a horseshoe shape, called tentacle crowns, and they attach to the seabed or other substrate through a stalk-like organ called a fleshy stem.
The fossil record of parasites is sparse, but for the most part, parasites only revolve around one or a few samples, and whether one organism will have a negative impact on another has always been speculative.
The researchers analyzed fossil populations of the 512 million-year-old Cambrian brachiopod Oolong shrimp shell found in Yunnan. They found that many of the shells of the oolong new round shells were covered with a tube dwelling organism, while the oolong new round shell covered with the tube dwelling organism was significantly smaller, and the attachment direction of these tubular organisms was always consistent with the direction of the feeding water flow of the brachiopods themselves. "Therefore, we believe that this tube organism affects the size of the host by stealing the host's food, and also greatly reduces its biomass, which is obviously a parasitic ecological phenomenon." Zhang Zhifei, the first author and corresponding author of the paper and a professor in the Geology Department of Northwest University, said.
Zhang Zhifei said that the study traced the shell organisms back to the early Cambrian period, pushed forward at least 30 million years, and found the earliest exclusive boarding relationship on the earth for the first time through fossil biostatistics, demonstrating that the monopolistic theft parasitism is the earliest parasitic relationship that disappeared on the earth. At the same time, it also opened the study of Cambrian parasites, showing that adversarial biological relationships are an important driving force for the evolution of animal ecosystems on Earth.
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