An unusually well-preserved "Marine Dwarf World" from 462 million years ago was found at Castle Bank, Wales by a team led by the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS). The site comprises over 150 species, with many of miniaturized body size. It is one of the world's most unexpected fossil sites.
https://phys.org/news/2023-05-middle-ordovician-marine-dwarf-world.html
https://phys.org/news/2023-05-middle-ordovician-marine-dwarf-world.html