Fritzolenellus

Gapp, I. Wesley & Lieberman, Bruce S., 2014, New olenelloid trilobites from the Northwest Territories, Canada, Zootaxa 3866 (4), pp. 479-498 : 494

Fritzolenellus sp. aff. hanseni ( Poulsen, 1932)

Fig. 3.1

Paedeumias hanseni Poulsen 1932 .

Olenellus hanseni Stein 2008 , fig. 8 B, 8 C.

Material examined. KUMIP 355562–355563.

Discussion. This species shares the following characters with O. hanseni , which is known from the Ella Island Formation of North-East Greenland: the anterior cephalic margin is narrow (sag.) and developed as a raised ridge; an anterior glabellar furrow present; the anterolateral margins of the glabella deflect posteriorly at approximately at 40 degrees; LA length (sag.) equal to combined length (sag.) of LO, L 1, and L 2; the ocular lobe terminates posteriorly at SO; a prominent ocular furrow extends the length of the ocular lobe; the extraocular area is approximately the width (tr.) of the glabella at L 2; S 3 is strongly convex and conjoined adaxially; L 2 and L 3 merge abaxially; S 2 is convex anteriorly and conjoined adaxially; L 1 is straight and not conjoined adaxially; the lateral margins of LO and L 1 are straight and parallel to a sagittal line; SO is slightly convex posteriorly, and not conjoined adaxially; posterior margin of LO convex posteriorly; the posterior border between LO and the intergenal angle is parallel to a transverse line; the intergenal angle is approximately 30-40 degrees; and the genal spines are relatively long (exsag.). Cowie & McNamara ( 1978) suggested O. hanseni was very similar to Fritzolenellus lapworthi ( Peach and Horne, 1892) , with the primary differences involving the length of the ocular lobes. Stein ( 2008) reiterated this suggestion, and also recognized the absence of a prominent parafrontal band and the presence of a plectrum when compared with F. lapworthi . These features are also observed in the specimens presented here. Due to the quality of preservation and the limited material, we are only tentatively assigning these specimens to F. hanseni .

Occurrence. Olenellus zone or Waucoban Series, Dyeran stage, sensu Webster ( 2011 a, b) and Webster et al. ( 2011), early Cambrian, Sekwi Formation, Mackenzie Mountains, Northwest Territories, Canada, Section 4, 430 – 435 m above the base of section.