Bradoriida (Arthropoda) from the early Cambrian of North Greenland

• Published in: Transactions of the Royal Society of Edinburgh: Earth Sciences
• Main Authors: Siveter, David J., Williams, Mark, Peel, John S., Siveter, Derek J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1995
• Subjects: Greenland; North Greenland; Siberia
• Online Access: http://dx.doi.org/10.1017/s0263593300006374; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263593300006374

ABSTRACT Marine shelf siliciclastics of the early Cambrian Buen Formation of North Greenland have yielded the earliest abundant, well localised Bradoriida (Arthropoda) from the Laurentian part of North America: the shelf-dwelling Petrianna gen. nov. Petrianna apparently has a fairly rigid, phosphatic shell. Its assignment to the Cambriidae, a family markedly dissimilar morphologically from the phosphatocopines (the only Bradoriida hitherto regarded as having a primary phosphatic shell), implies rejection of the criterion of carapace composition in the ordinal/subordinal classification of Bradoriida. Petrianna confirms the Bradoriida as a consistent component of the earliest arthropod faunas. Cambriids are currently known only from the early Cambrian of Greenland, Siberia and China and offer potential for correlation. Cambriid occurrences span parts of the Redlichiid, Olenellid and Bigotinid trilobite faunal realms but are known only from tropical/subtropical regions, thus indicating possible palaeolatitudinal controls on their distribution.