Exceptional preservation and unexpected diversity of radiolarians in the aftermath of the Permian–Triassic mass extinction

The Early Triassic is typically described as an interval of poor fossil preservation and low diversity in the aftermath of the Permian–Triassic mass extinction. For radiolarians, very little information is available due to the lack of known radiolarian‐yielding locations. However, well‐preserved radiolarians, including the oldest (Griesbachian, Early Triassic) occurrence of fossilized central capsule membranes, have been recovered from a shallow marine Permian/Triassic boundary succession at Lusitaniadalen (Svalbard) and described herein. Eleven species from seven genera of Radiolaria have been found, including three new species (? Entactinia sengeri , Archaeocenosphaera plankei and Thaisphaera ullarinmanae ) and two new subspecies (? Entactinia meishanensis smyraksikorae and Grandetortura nipponica stepheni ). Combined with the unexpectedly high diversity of other organisms from the Permian/Triassic boundary in Svalbard, these new data further indicate that Svalbard represents either a previously unknown refuge or a locality of exceptional preservation in the aftermath of the mass extinction event.