Paleontology & Fossils

‘Marine dwarf planet’ from the Middle Ordovician was discovered near Castle Bank, Wales.

A team led by the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) discovered an unusually well-preserved “Marine Dwarf World” from 462 million years ago at Castle Bank, Wales. Over 150 species can be found at the site, many of which have bodies that are smaller than life. It is one of the most surprising fossil sites in the world.

The review is distributed in Nature, Environment, and Advancement on May 1.

One of the very few places where complete organisms and soft tissue are preserved, Castle Bank in Powys offers an unparalleled perspective on life’s evolution. Burgess Shale-type faunas, named after the classic Canadian fossil-bearing Burgess Shale deposit, are among these sites’ best.

Most of these locations are in rocks from the Cambrian period, which was between 542 and 485 million years ago and was when animal fossils first appeared. Notwithstanding, practically none happen in post-Cambrian rocks. As a result, paleontologists know a lot about marine life from the Cambrian but less about how it changed in the following periods.

“The majority of fossil sites of this significance are investigated for many years, and it’s probable that this will be no different.”

Dr. Lucy Muir, authors of this study, near Llandrindod, central Wales.

Palace Bank is from the center of the succeeding Ordovician time frame, nearly quite a while ago, and rivals the best of the Cambrian stores in variety of fossils and phenomenal degrees of safeguarding.

The noteworthy new collection was found in 2020 by Dr. Joe Botting and Dr. Lucy Muir, two creators of this review, close to Llandrindod, focal Ridges.

Up until this point, over and beyond 150 species have been recovered, practically every one of them new. Despite being only 1–3 millimeters long, many of the animals retain minute details. They include a wide variety of worms, sponges, starfish, and many more arthropods like horseshoe crabs and crustaceans. In certain creatures, interior organs, for example, stomach-related frameworks and even nerves, are protected, along with the appendages of small arthropods and sensitive channels taking care of arms. The best faunas from the Cambrian have such exquisite detail, but the Ordovician has not.

(A) a potential priapulid (NIGP175887); (B) a problematic tubicolous organism (NIGP175892). Credit: NIGPAS

Many of the shelly fossils found in the Castle Bank fauna were typical of the Middle Ordovician marine organisms that lived there.

The variety of fossils also includes a number of unusual finds, such as unexpectedly early fossils that resemble modern goose barnacles, cephalocarid shrimps, which have no fossil record at all, and possibly even a marine relative of insects, as well as strangely late examples of Cambrian animals that look like opabiniids (weird proto-arthropods with a long proboscis) and wiwaxiids (slug-

The Cambrian saw the beginning of significant creature gatherings. Additionally, the Ordovician was a pivotal time in the evolution of life, marked by extraordinary animal diversity that resulted in numerous hard skeletons and fossils. Additionally, by the end of the Ordovician, more familiar ecosystems, such as coral reefs, had emerged. However, there has been a significant “gap” between these two evolutionary events up until this point.

Questions about the transition of ecosystems from the Cambrian style (which was similar across much of the world) to the much more diversified ecology that we see today will be answered by a new Burgess Shale-type fauna from the middle of this period, which will help close this gap.

Based on this fauna, a few papers have been written about sponges and one about Mieridduryn, a primitive relative of modern arthropods. More papers will be published, and collections are being created. “Most fossil deposits of this importance have been studied for many decades, and this is likely to be no exception,” Dr. Muir asserts.

Joseph Botting and two teammates from NIGPAS (Y. D. Zhang and J. Y. Mama) have been teaming up on the Konservat-Lagerstätte of Ordovician, and portions of this work, including the perception and examination of some examples and reproduction, are finished in NIGPAS under the help of CAS.

The Castle Bank fauna is regarded as a transitional interval between sponges of the Cambrian and those of the Anji fauna, another Burgess-Shale-type fauna from Zhejiang, China, to which the researchers have devoted themselves for years. This has important implications for the evolution of sponges, particularly Hexactinellida.

More information: A Middle Ordovician Burgess Shale-type fauna from Castle Bank, Wales (UK), Nature Ecology & Evolution (2023). DOI: 10.1038/s41559-023-02038-4

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