The generic name Nordia (N. lepida Rozova, 1968, by original designation) was proposed by Rozova (1968: 108) for a new trilobite genus from the Upper Cambrian of the Tajmyr peninsula (NW Siberia, Krasnojarsk territory, Russian Federation). However, this name was preoccupied by Nordia Jairajpuri and Siddiqi (1964: 2) which is served as a type for a family Nordiidae Jairajpuri & Siddiqi and subfa...

Abstract A short stratigraphic interval near Bulin in western Hunan (China) yields multiple specimens of the ~514-Myr-old oryctocarine trilobite Oryctocarella duyunensis . Size data obtained from these indicate that, meraspid degree 1 onward, degrees represent successive instars. Meraspid growth persisted until a terminal stage was reached, providing first example determinate trilobites and, no...

This study presents a detailed morphological analysis of a new species belonging to the blind trilobite Trimerocephalus McCoy, 1849, T. chopini n. sp., based on exceptionally well preserved articulated specimens from the Late Devonian (Early Famennian) of the Holy Cross Mountains in central Poland. The occurrence of this taxon in Kowala Quarry near Kielce has been reported previously, with spec...

Xandarellida is a well-defined clade of Lower Palaeozoic non-biomineralized artiopodans that is exclusively known from the early Cambrian (Stage 3) Chengjiang biota of South China. Here we describe a new member of this group, Xandarella mauretanica sp. nov., from the middle Cambrian (Stage 5) Tatelt Formation of Morocco, making this the first non-trilobite Cambrian euarthropod known from North ...

OK, they are cute, but why should a developmental biologist care about them? Onset of calcification early in ontogeny coupled with gradual, progressive morphological development permits the recognition of growth sequences for over a hundred trilobite species. Striking variation in the number of trunk segments at maturity across ontogeny and phylogeny, coupled with the curious pattern of segment...

The Steptoean Positive Isotopic Carbon Excursion (SPICE) is a prominent +4–5‰ shift in the Cambrian δ13C record used for global chronostratigraphic correlation. onset of this excursion traditionally placed at base Pterocephaliid trilobite biomere (base Furongian Series). Recent studies have documented local controls on expression SPICE and emphasize need standards these complex biogeochemical s...