Elliptocephala jaredi, Gapp, I. Wesley & Lieberman, Bruce S., 2014

Gapp, I. Wesley & Lieberman, Bruce S., 2014, New olenelloid trilobites from the Northwest Territories, Canada, Zootaxa 3866 (4), pp. 479-498 : 487-488

Elliptocephala jaredi sp. nov.

Fig. 1.1, 1.2, 1.4, 1.5

Type material. Holotype KUMIP 355534. Paratypes KUMIP 355535-355544 and PWNHC-2013.23.6-16.

Etymology. In honour of Jared Lieberman, son of BSL.

Diagnosis. LA contacts anterior cephalic margin; LA approximately 1.5 times combined length of LO and L1; glabellar furrows not conjoined; S3 strongly convex; ocular lobes terminate posteriorly opposite SO; posterior cephalic margin parallel to a transverse line.

Description. Anterior cephalic margin forms smooth, semi-circular arc; length of anterior cephalic border is short to moderately long (length = 0.5–1 times length [sag.] of LO); LA contacts anterior cephalic margin; anterior margins of the frontal lobes at each side of the midline deflected posteriorly at roughly 40 degree angle relative to a transverse line; length (sag.) of LA long, equal to 1.5 times length of LO and L1 adaxially; LA does not expand prominently dorsally; lateral margins of LA proximal to lateral margins of LO; ocular lobes contact frontal lobe at posterolateral margins of frontal lobe; ocular furrow present; line from posterior tip of the ocular lobe to junction of posterior margin of lobe with glabella forms 10-20 degree angle with sagittal line; posterior tips of the ocular lobes developed opposite SO; anterodistal margins of L3 formed by ocular lobes; SO, S1, and S2 are convex, S3 very convex; none of the axial furrows are conjoined adaxially; L2 and L3 do not merge abaxially; lateral lobes present on LO; extraocular area approximately two-thirds width of glabella, gently convex; polygonal fracturing visible on some cephala; posterior cephalic border parallel with transverse line or directed slightly posteriorly; intergenal spine and intergenal angle not present; genal spines directed posteriorly approximately 10 degrees relative to a sagittal line, extend back approximately three thoracic segments (inferred based on typical relative length [sag.] of LO as compared to typical relative length [sag.] of prothoracic axial rings).

Discussion. This species is assigned to the genus Elliptocephala on the basis of character states such as: the length of LA (sag.) is approximately 1.5 times the length (sag.) of LO and L1; the anterior margins of the frontal lobe at each side of the midline deflects posteriorly at approximately 40 degrees relative to a transverse line; L2 and L3 do not merge abaxially; the abaxial margins of L2 diverge anteriorly; S2 is convex anteriorly; the ocular lobe has a prominent ocular furrow; the line from the posterior tip of the ocular lobe to the junction of the lobe with the glabella forms a 10 to 20 degree angle with the sagittal line; the anterodistal margins of L3 are formed by the ocular lobes; and polygonal fracturing is visible on cephala.

Elliptocephala jaredi shares many similarities with Wanneria walcottana ( Wanner, 1901) . This includes the fact that none of the glabellar furrows are conjoined adaxially, S3 is strongly convex, there is an absence of anastomosing ridges on the extraocular area, the frontal lobe contacts the anterior cephalic border, and the abaxial margins of the glabella at L1 relative to LO are constricted. Differences include the fact that the ocular lobes extend further posteriorly in E. jaredi , as well as the presence of lateral lobes, shorter genal spines, LA not bulging much further laterally than LO, and the length of LA relative to LO and L1 is longer in E. jaredi . Due to the similarities between E. jaredi and W. walcottana , it is likely that E. jaredi is positioned basally within Elliptocephala . However, further phylogenetic investigation is needed to test this, and the fact that LA does not bulge much further laterally than LO is somewhat distinctive for Elliptocephala .

Occurrence. Olenellus zone or Waucoban Series, Dyeran stage, sensu Webster (2011a, b) and Webster et al. (2011), early Cambrian, Sekwi Formation, Mackenzie Mountains, Northwest Territories, Canada, Section 2, 260– 395 m above the base of section, Section 3, 700– 800 m above the base of the section, and Section 4, in float).