Pinnuloharpes torquis, Johnson, 2024

Johnson, Robert G., 2024, Devonian Harpetidae from the central and eastern Anti-Atlas, Morocco, Zootaxa 5450 (1), pp. 1-185 : 94-95

Pinnuloharpes torquis n. sp.

Plate 37A–O

Diagnosis. Genicranium broad (width (tr.) 1.2 times length (sag.)), and genal roll gently sloping anteriorly. Glabella mildly tectiform, and S1 small depression in axial furrow. Alar furrows effaced. Girder very broad (sag., exsag.) and with central row of large perforations. Prolongation long (exsag,), 1.2 times cephalic length (sag.); external and internal rims flexing abaxially close to distal end of prolongation.

Etymology. Named for the necklace-like perforated girder. Torquis, Latin for collar or neckless.

Material and occurrence. Holotype: NHMUK It 29354 (1), Pl. 37E–J , from an upper Eifelian horizon, in an outcrop 3.8 km west of Ksar Hannabou and 8.3 km S.S. W. of El Jorf ( Fig. 2B, Map 6, site 9) a dorsal exoskeleton of a cephalon which largely overlies another cephalon , Paratype NHMUK It 29354 (2), Pl. 37E . Paratype: NHMUK It 29353, Pl. 37A–D , from type locality and horizon ( Fig. 2B, Map 6, site 7), dorsal exoskeleton of cephalon only . Paratype: NHMUK It 29355 (1), Pl. 37K–O , from type locality and horizon ( Fig. 2B, Map 6, site 10), dorsal exoskeleton of partial cephalon . Paratype NHMUK It 29355 (2) not figured .

Other material: Pinnuloharpes aff. torquis : NHMUK It 29329, Pl. 38A–E , from an upper Eifelian horizon, Tamgoute Bulgan ( Fig. 2B, Map 6, site 20), dorsal exoskeleton of cephalon only.

Description. Cephalon ovoid, widest at mid-point between alae and eye lobes. Glabella narrow, width (tr.) under 60% of length (sag.) of glabella anterior to S0, with rounded crest, tectiform flanks and no sculpture. L1 not inflated, and S1 shallow depression in axial furrow only. Axial furrows straight, converging anteriorly at an angle to axis of just under 15 o. Preglabellar furrow shallow and bowed upwards in anterior view. Occipital furrow shallow, medially straight. Occipital ring not medially broadened, same width (sag,) as posterior border (exsag.), without sculpture and, viewed laterally, same height as glabella anterior to S0. Occipital node of moderate size, barely inflated and located on anterior slope of occipital ring. Posterior border moderately wide (tr.), at around 45% of occipital ring width (tr.). No preglabellar field and alar furrow effaced.

Genal area broad, width (tr.) around 65% of length (exsag.). Eye lobes large (exsag.) (50% of width of glabella at S1); barely inflated; reniform; without sculpture on dorsal surfaces and with two subtriangular ( Pl. 37N, O ) lenses per eye lobe. No eye ridge or genal ridge. Inner margin of fringe not marked by bigger perforations. Anterior boss inflated and joined to glabella. Genal roll sloping very gently anteriorly (≈ 430), moderately steeply laterally (≈ 600), and genal roll perforations smaller than on brim and becoming smaller away from girder. Girder very wide (sag., exsag.), nearly 4% of width (tr.) of genicranium, with central row of big perforations. Brim narrow (sag.), around 28% of cephalic length (sag.), sloping moderately at just under 200 and with straight profile. Brim width ratio around 0.90. Standardised brim perforations large, with diameter of over 200 µm and no caeca on brim. External rim stout and without sculpture on dorsal surface. Marginal band near vertical, lacking ridges and tubercles. Prolongations very long (exsag.), around 1.2 times cephalic length (sag.) and in lateral view, height at midpoint less than half height of prolongation at junction with posterior border. In dorsal view, internal and external rims curving adaxially., Profiles of internal rims concave in lateral view, and meet exterior rim before joining at end of prolongations. Dorsal surfaces of internal rim smooth and genal spines long, following curve of exterior rim. Extension of girder meeting internal rim one third of way down prolongation. Whole brim steepens moderately on prolongations.

Thorax, pygidium and hypostome unknown.

Remarks. Pinnuloharpes torquis is similar to P. apteros but differs by having: axial furrows that are less convergent anteriorly and are straight not gently convex; a preglabellar furrow that in anterior view is bowed upwards not straight; eye lobes located further from the inner margin of the fringe; wider (tr.) posterior border and an inner margin of the fringe which is concave across the anterior of the genicranium either side of the glabella, rather than being straight as the case of P. apteros ; an anterior boss that is more inflated and reaches down to girder; a wider (sag. and exsag.) girder that has a weak girder kink and central row of large perforations not found on the girder of P. apteros ; a brim width ratio of over 0.86 compared to 0.77 for that of P. apteros ; a marginal band without ridges; brim extensions on the prolongations that steepen less strongly. Prolongations that are longer (exsag.) than the length (sag.) of the cephalon length and over 15% longer than those of P. apteros ; and internal rims which in lateral view, have a concave rather than straight profile and which meet before the end of the prolongations, rather than at the end as those of P. apteros do.

Pinnuloharpes torquis differs from P. aff. torquis ( Pl. 38A–E ) in having: a cephalon that in dorsal view is ovoid and widest at the mid-point between the alae and eye lobes, while that of P. aff. torquis is mildly pyriform and widest at the alae; a glabella with no muscle insertion furrows at S2, S3 or S4, whereas P. aff. torquis has furrows at S2 and S3; a more inflated boss, but no bigger perforations marking the inner margin of the fringe as it crosses the boss; a wide girder with a central row of large perforations, which are absent in P. aff. torquis ; a weak girder kink, rather than none; a less steeply-sloping brim, which has a straighter, less convex profile and standardised brim perforations some 36% smaller at ≈220 µm; much stouter external rims; internal rims that curve adaxially in dorsal view, rather than being subparallel, and in lateral profile, are concave not straight; the extension of girder on the prolongations meets the internal rim a quarter of the way down, rather than dissipating before reaching the internal rim as it does in P. aff. torquis ; and in lateral view, the internal and external rims of P. torquis meet closer to the end of the prolongations than those of P. aff. torquis .

Genus Stoloharpes n. gen.

Type species. Stoloharpes rissaniensis n. sp.

From a horizon near the top of the Eifelian, Rissani, Anti-Atlas, Morocco

Diagnosis. Cephalon is pyriform, and genicranium narrow to very narrow (width (tr.) over 85% of length (sag.)). Glabella carinate and joined medially to barely-inflated anterior boss. Preglabellar furrow very shallow and bowed upwards in anterior view. Occipital furrow medially bowed posteriorly. Genal roll gently sloping anteriorly (at under 420 with horizontal). Brim convex, sloping steeply at between 310 and 400 and quicky steepening to near vertical on prolongations. External rims tilted outwards and marginal band sloping down under cephalon. Internal rim has straight profile in lateral view. Thorax with over 24 segments. Outer portion of pleurae in line with inner portion and curving anteriorly distally.

Etymology. From the Greek word στολή (stolē). The shape of the convex brim around the genicranium resembles a stole.

Discussion. Stoloharpes sister genus is Pinnuloharpes and the two genera are compared in the systematics for Pinnuloharpes above.

Amongst the species described below, Stoloharpes retiarius may possibly belong to another unnamed genus. Eifelian Material figured by Lebrun, P. (2018, Page 229 Fig.A) from Jorf, Errachidia, Morocco and Basse and Müller (2004, tafel 26, Fig. 340) from Wissenbach-Schiefer, Schiefergebirge, Harz, Germany have similar morphologically features but more material is required to determine whether they form a separate clade with S. retiarius and justify the erection of a new genus.

Stoloharpes obuti and S. convexus have been reassigned from Kielania . S. obuti is of Lochkovian age whereas all other species of Stoloharpes are from the middle to upper Eifelian and it may be on more material becoming available that S. obuti will be found to belong to another genus.

Cladogram Figs 9 , 10e show all the species included in the genus.

Figures

FIGURE 9. Cladogram consensus of 636 trees with a 31 node collapse and each tree L = 1968, Ci = 12 and Ri =48

FIGURE 10a. Lioharpes and Maghroharpes from tree 1 of 60 found using seed 7

PLATE 37. A–O Pinnuloharpes torquis n. sp., from “Harpes Couche”, El Otfal Formation, upper Eifelian, Ksar Hannabou. A–D dorsal exoskeleton of cephalon only, paratype, NHMUK It 29353 (Fig. 2B, Map 6, site 7). A, dorsal, B, lateral and C, anterior view. D, dorsal view of brim perforation. E–J 2 dorsal exoskeletons of cephala only (one cephalon largely covering the other), holotype, NHMUK It 29354 (1) and paratype NHMUK It 29354 (2) (Fig. 2B, Map 6, site 9). NHMUK It 29354 (1) E, dorsal view, F, lateral and G, anterior view. H, anterior dorsal view of perforations on genal roll and brim. I and J, dorsal view of impression of ventral surface of cuticle in genal area and brim perforations, respectively. NHMUK It 29354 (2) E, dorsal view. K–O dorsal exoskeleton of partial cephalon, paratype, NHMUK It 29355 (1) (Fig. 2B, Map 6, site 10). K, dorsal and L, lateral view. M, dorsal view of brim perforations, N and O, lateral view of eye lobes (uncoated). Scale bars shown represent 1 cm unless otherwise indicated.

PLATE 38.A–E Pinnuloharpes aff. torquis, dorsal exoskeleton of cephalon only, El Otfal Formation, upper Eifelian, Tamgoute Bulgan (Fig. 2B, Map 6, site 20), NHMUK It 29329. A, dorsal, B, lateral and C, anterior view. D, lateral view of eye lobe (uncoated) and E, dorsal view of brim perforations. F–I Pinnuloharpes aff. apteros, dorsal exoskeleton of cephalon only, El Otfal Formation, upper Eifelian, “Harpes Couche”, Ksar Hannabou (Fig. 2B, Map 6, site 6), NHMUK It 29379. F, dorsal, G, lateral and H, anterior view. I, lateral view of eye lobe. J–O Pinnuloharpes apteros n. sp.,dorsal exoskeleton, El Otfal Formation, upper Eifelian, Tamgoute Bulgan (Fig. 2B, Map 6, site 18), holotype, NHMUK It 29358. J, dorsal, K, anterior and L, lateral view. M, lateral view of pleurae, N, dorsal view of brim perforations and O, posterior view of pygidium. Scale bars shown represent 1 cm unless otherwise indicated.