trilobite 3 - 3d model earth sciences university newcastle landy42 5cb18ea constructed plaster cast specimen part display collection uon since trilobites segmented most common fossils them often just pygidium &lsquo tail plate&rsquo largest single fragment more unusual intact like preserved note not original arthropods same phylum insects strictly palaeozoic arising cambrian explosion&rsquo becoming extinct during permain-triassic mass extinction do know detailed taxonomy so if anyone out there knows leave comment would happy add description