Condylopyge


Condylopyge is a genus of agnostid trilobite that lived during the late Lower and early Middle Cambrian, in what are today Canada, the Czech Republic, England and Wales, France, Germany, Italy, Morocco, the Russian Federation, Spain, Turkey and Sweden. It can easily be distinguished from all other Agnostida because the frontal glabellar lobe is notably wider than the rear lobe. It belongs to the same family as Pleuroctenium but the frontal glabellar lobe does not fold around the rear lobe, as it does in that genus.
Condylopyge is long ranging, possibly spanning the early Cambrian Terreneuvian Series in Nuneaton, central England into at least Drumian strata at various locations elsewhere.

Description

Condylopyge is isopygous with cephalon and pygidium of approximately equal size. The characteristic lateral expansion of the frontal glabellar lobe, occipital structures, and pygidial axis with three pairs of lateral lobes and a terminal piece differentiate Condylopygidae from all other agnostids. The presence of a spine on the occipital band has been recognised as a distinctive feature of condylopygoids. Condylopyge is easily distinguished from its sister taxon, Pleuroctenium, because the frontal glabellar lobe does not extend partially around the posterior glabellar lobe. Furthermore the frontal glabellar lobe is never bisected medially as in Pleuroctenium. The pygidium may carry a pair of backwardly directed spines, but this also occurs regularly in Pleuroctenium.

Distribution

  • C. eli, was originally collected from the Jbel Wawrmast Formation, Bou Tiouit section, at 51.1 m, in Morocco, Morocconus notabilis Zone. Holotype pygidium refigured by Geyer & Vincent.
  • C. antiqua was recovered from the latest Lower to the early Middle Cambrian of Italy.
  • C. amitina From the Purley Shale Formation, Camp Hill, St. Paul's Church, Stockingford, Nuneaton, Warwickshire, England Biosubzone age); Newgale Formation, Pen-y-Cyfrwy Member. Known examples of this species cannot be distinguished from C. carinata and cambrensis may in fact be a senior synonym of carinata.
  • C. sp. occurs in the early Middle Cambrian of the United States.
  • C. sp. also occurs in the early Middle Cambrian of Spain.
  • C. carinata vicina Egorova in Savitsky et al. is from the Cambrian Judomian–Olenetsky type section in the Kuonamsky Complex deposits, Siberian Platform, Russia.
  • C. sp.? Material tentatively assigned to Condylopyge has been reported from the Leny Limestone of Perthshire, Scotland by Fletcher & Rushton who suggested that the species appears to occur also in the Kounamkites Zone of the River Nekekit area, Siberia, and figured by Egorova & Savitsky as “Condylopyge carinata vicina”.