ALT Professor John Marshal with glasses and a hat smiles at the camera while sitting beside a rocky outcrop. He is wearing a beige vest and blue sleeves. In front of him are geological tools including a hammer, measuring tape, and a notepad with notes.

ALT Two people in bright orange survival suits and life jackets are on a small inflatable boat. They are navigating icy waters, with icebergs visible in the background and a cloudy sky overhead. One person is handling the motor, while the other sits facing forward.

ALT Professor John Marshall, in outdoor attire, operates a power drill on a rocky, barren mountainside. He wears a dark hat, glasses, and has a gray beard. The terrain is steep with loose dirt and stones.

ALT Red and black tents are pitched on a snowy, rocky slope under an overcast sky. The ground is thinly covered with snow, revealing many stones. The background shows a large, snow-dusted hill.

ALT Top: Grid including illustrations (top row) and photographs (bottom row) of Palaeozoic echinoid fossils demonstrating examples of 5 taphonomic grades used in the paper. Left to right: TG1, MCZ:IP:103620, disarticulated spine and interambulacral plate of the archaeocidarid Archaeocidaris sp.; TG2, LACM 2020.1, pile of disarticulated interambulacral plates and spines from Archaeocidaris sp.; TG3, MCZ:IP:101936, fragment of a test of the palaechinid Maccoya intermedia showing ambulacral and interambulacral plates; TG4, YPM 26552, denuded test of the lepidesthid echinoid Lepidesthes colletti; TG5, NHMUK Pal E 76888, holotype of Archaeocidaris whatleyensis, an articulated test preserved with covering spines; scale bars (with photographs) are 1 cm. Bottom: Coloured plot showing the temporal distribution of taphonomic grades from the Ordovician (on the left) to the Permian. Vertical axis represents frequency of occurrence. Different colours indicate the 5 different taphonomic grades.