Atlanticalymene bardensis Adrain & Karim 2020, n. sp.

Atlanticalymene bardensis n. sp. Plates 1–7 1965 Ischyrophyma? sp. ind.; Whittington, p. 340, pl. 19, figs 16, 19, 20. 1965 Komaspidid? pygidium; Whittington, p. 374, pl. 39, figs 8, 9. 1965 aff. Calymenidius sp. ind.; Whittington, p. 419, pl. 59, figs 10, 12–15. 1967 Protocalymene sp.; Ross, p. D27. 1970 Protocalymene sp.; Ross, p. 92. 1977 Protocalymene sp.; Siveter, p. 388. 1990 Protocalymene sp.; Fortey, p. 568. 1997 Sthenarocalymene sp.; Adrain and Fortey, p. 105. 1999 “aff. Calymenidius sp. ind.” of Whittington; Fortey and Droser, p. 199. 2002 Protocalymene sp.; Turvey, p. 56. 2011 Calymenia sp.; Shaw and Bolton, p. 417. 2014 Sthenarocalymene sp.; Zhou et al., p. 115. 2016 Sthenarocalymene sp.; Zhou et al., p. 322. Material. Holotype, cranidium, GSC 135298 (Pl. 2, figs 10, 13–15), and assigned specimens GSC 135289–135297, 135299–135358, from horizons TCM 13, TCM 14, and TCM 18, Table Cove Formation (Darriwilian), coast opposite Marechal Island, near Main Brook, Hare Bay, Great Northern Peninsula, western Newfoundland. Assigned specimens GSC 18345, 18346, 18369, 18569, Table Cove Formation (Darriwilian), Table Cove, west coast of Great Northern Peninsula, western Newfoundland, Canada. Etymology. From Bard Island Tickle, a local name for the type locality. Diagnosis. Interocular fixigena very broad; librigena subtriangular in outline, posterior facial suture hardly bowed compared with other calymenine taxa; eye small; rostal plate with gently ventrally curved ventral sector, longer exsagittally than sagittally in plan view, smooth and posteriorly concave doublural sector; hypostome with large anterior wings, lacking rhynchos, and with posteromedian spine in addition to the conventional paired posterolateral spines, posterior border long (sag.; exsag.); thoracic segments with anterior and posterior pleural bands subequal in length (exsag.), tuberculate sculpture on both but more prominent on posterior band; pygidium with four distinct axial rings, fourth not fully defined by ring furrow posteriorly in some specimens; pleural furrow of only the first segment well impressed distal to fulcrum; posterior of axis slightly inflated with a pair of subdued lateral swellings in large specimens; pleural region with faint interpleural furrows and dense fine tuberculate sculpture. Description. Cranidial measurements are based on the large, intact specimens of Pl. 1, fig. 10, Pl. 2, figs 1, 2, 10, 12, 16, 18, and Pl. 3, figs 1–3, 12. Where part of the cranidial morphology was preserved on only one side, the distance to the sagittal line from this side was doubled. Cranidium strongly vaulted, covered with densely spaced tubercles that are sometimes flattened; maximum cranidial sagittal length 50.6% (47.5–55.3) maximum width across posterior border; width across anterior border furrow 42.1% (39.1–45.4) maximum width across posterior border; distance across γ 66.5% (61.8–70.9) maximum cranidial width; anterior border with length (sag.) 75.9% (62.7–95.5) LO sagittal length, slightly shorter (exsag.) abaxially, forming strongly bowed arch in anterior profile; anterior border flexed upward and back toward anterior tip of glabella, so that it partially obscures border furrow in anterior view, but it does not abut anterior margin of glabella in transverse profile; anterior border with sculpture of small and medium sized, densely spaced somewhat flattened tubercles, tubercles become smaller toward rostral suture; anterior border furrow confluent with preglabellar furrow, long (sag.), with length (sag.) nearly equal to that of anterior border in dorsal view on some specimens, dorsally concave, much deeper and shorter (exsag.) opposite frontal area; anterior sections of facial sutures gently laterally convex opposite anterior border, laterally concave opposite anterior border furrow, and strongly, but unevenly, laterally bowed opposite frontal areas with bow strongest opposite anterolateral corners of glabella; frontal areas strongly inflated, sloped strongly downward and mostly facing anteromedially with exsagittal portion facing slightly obliquely, anteriormost portion nearly vertical to slightly recurved under cranidium; palpebral lobe small, lobe strongly laterally bowed, comma shaped, with portion posterior to δ slightly longer than portion anterior to δ; distance across γ 131.5% (124.3–142.7) cranidial sagittal length; distinct furrow clearly differentiating palpebral lobe from fixigena, furrow is shallow anteriorly, but deep along posterolateral corner of lobe; eye ridge faint, but discernible on dorsal surface of most specimens, clearly visible ventrally (Pl. 2, fig. 8), running obliquely from anterior portion of palpebral lobe to point just behind fossula; interocular fixigena very broad, with moderately strong dorsal inflation, sloping toward glabella; posterior fixigena with inflation similar to frontal area, strongly sloping downward from horizontal plane; fixigena covered with sculpture of medium and small sized scattered tubercles, tubercles become smaller and less dense toward genal angle; posterior section of facial suture nearly straight, slightly posterolaterally directed to nearly transverse; posterior border furrow relatively long (exsag.) and deep, nearly transverse, deeper and forming a sharp contact posteriorly with posterior border, shallower and forming a more gradational contact anteriorly with posterior fixigena, distal and proximal tips shallower; posterior border dorsally inflated, shortest (exsag.) proximally, lengthened distally from fulcrum, then slightly shortened distally from point opposite distal margin of posterior facial suture; border with fine background tubercles and a few larger tubercles arranged linearly along portion of border between fulcrum and axis; posterior margin of posterior border transversely straight to fulcrum, directed more posterolaterally from fulcrum to point opposite distal margin of posterior facial suture, directed anterolaterally from this point distally; ventral margin of posterior border between fulcrum and axis with narrow transverse articulating groove, additional thin subtriangular strip of doublure present beneath posterior border from fulcrum distally; genal angle developed into very short posterolaterally directed projection; glabella subtrapezoidal in dorsal view, with maximum width across L1 98.8% (87.9–104.1) sagittal length excluding LO, sagittal length (excluding LO) 64.8% (61.9–71.7) that of cranidium, strongly convex and dorsally inflated, with apex sitting above fixigena and situated opposite posterior fixigena in lateral view, anterior portion of glabella faces anteriorly and is nearly recurved under margin; axial furrows clearly impressed along majority of course, shallow and nearly effaced opposite LO, deeper and laterally bowed around L1, furrow broad in front of L1 forming a subtriangular depression along the lateral glabellar margin, tapers anteriorly, but broadens again at intersection with anterior border and preglabellar furrows, width across posterior contact of furrows with posterior margin 58.8% (53.6–63.7) cranidial sagittal length, laterally confluent with posterior bor- der furrow; S1 deep, completely isolating L1 on some specimens (e.g., Pl. 2, fig. 2), but not quite on others (e.g., Pl. 2, fig. 10); S2 poorly developed, barely visible on some specimens; L1 bulbous, subtriangular, with strong dorsal inflation; L2 and L3 not prominent and without independent inflation; sculpture of mostly small densely spaced tubercles covers glabella, with a scattering of larger tubercles superimposed; LO long, sagittal length 36.9% (35.0–40.7) that of cranidium, longer sagittally than exsagittally, anterior and posterior margins nearly transverse medially, with distal tips directed anterolaterally, sculpture of small scattered tubercles, slightly less densely spaced than on glabella, prominent median node, situated slightly anterior to midline; SO deep and short (sag.) medially, with distal tips deeper and deflected around base of L1, nearly transverse medially, anterior and posterior edges with sharp contact with rear of main glabella and LO respectively, joining axial furrow in smooth curve without obvious disruption in course; doublure of broad, semicircular articulating surface underlying LO, anterior margin terminating just before ventral expression of SO, mostly smooth with very faint transverse lines; fossulae expressed dorsally on most specimens. Librigenal measurements were made on the larger specimens of Pl. 4, figs 28–30, 34, 36, Pl. 5, figs 41, 44. Librigena subtriangular, with main body (excluding anterior projection) with maximum width 74.0% (66.7–76.9) exsagittal length; anterior section of facial suture with length 62.0% (55.1–68.3) exsagittal length of main body and posterior section of facial suture with length 53.5% (48.6–59.2) exsagittal length of main body; anterior section gently convex to nearly straight opposite field, with curve slightly more strong opposite abaxial half of field, curve strongly bent across lateral border; posterior section with gentle concave bow, curve continues smoothly across lateral border in some specimens, but in others curve is more strongly bent at lateral border; visual surface small, short, bulbous; eye separated from field by shallow furrow, deeper posteriorly, furrow covered by sculpture of small tubercles; field with background sculpture of very fine granules overlain by more prominent sculpture of densely spaced small and medium sized tubercles; lateral border furrow broad and relatively deep, distal tips slightly shallower on most specimens, background sculpture of fine granules covers furrow, but larger tubercles are mostly absent; lateral border with margin strongly but not evenly arcuate, curve strongest just anterior to midlength; border broad, strongly inflated with margin flattened forming a nearly vertical wall in ventrolateral profile (Pl. 5, figs 42, 43), with sculpture of very densely

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