Calymene quadrata King, 1923 and allied species of trilobites from the Ashgill Series of North Wales

Publisher Website
Google Scholar
Abstract
Summary: Calymene quadrata King is re-described. Two new species of similar age and provenance are erected and considered to be closely allied to quadrata; all three forms are thought to be best placed in genus Gravicalymene Shirley. G. pontilis sp.nov., the stratigraphically oldest form suggests derivation of the group from an ancestor such as G. deani Ingham. G. arcuata sp.nov. is the youngest form. Variation in the preglabellar area between the three forms argues for an expansion of the diagnosis of genus Gravicalymene; this would allow it to contain forms previously placed in genus Sthenarocalymene Siveter.

This publication has 4 references indexed in Scilit: