Agnostoid trilobites from the Henson Gletscher and Kap Stanton formations (Middle Cambrian), North Greenland

R.A Robison

doi:10.34194/bullggu.v169.6726

Abstract

This paper is based on diverse agnostoid trilobites in 10 collections from North Greenland.

Highlights

Agnostoid trilobites are abundant and diverse in 10 collections from the Henson Gletscher and Kap Stanton formations of North Greenland
At least 17 agnostoid genera are represented in the Henson Gletscher and Kap Stanton formations, of which Megagnostus and Schismagnostus are new
The geological setting, lithostratigraphy, and depositional environments of the Henson Gletscher and Kap Stanton formations are discussed in an accompanying paper by Ineson et al (1994)

Summary

Holm Dal Formation type section

Five agnostoid interval-zones have been defined in Middle Cambrian strata (Robison, 1984, pp. 5-9). One collection (GGU 298970) from the middle Henson Gletscher Formation of Nyeboe Land contains 12 species-group taxa (Fig. 2), including P. gibbus. The atavus Zone is well represented by abundant specimens in five collections, all from Nyeboe Land Of these collections, three (GGU 298969, 298974, 298975) are from the upper Henson Gletscher Formation (Fig. 2) and two (GGU 319789, 319790) are from basal beds of the Kap Stanton Formation (Fig. 3). The total zonal assemblage contains at 1east 24 species-group taxa, including P. atavus Fossils of this zone are widely distributed (Rowell et al, 1982), this is the first report of diagnostic species in Greenland Classification of agnostoid trilobites identified from the Henson Gletscher and Kap Stanton formations

Order Agnostida

GGU colleetion

Systematic descriptions

Class Trilobita

The transverse ridge on the posterior border furrow of