Zemlyacanthus menneri VERGOOSSEN 1997

• Main Authors: Burrow, Carole Jan, Murphy, Michael, Turner, Susan
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2023
• Subjects: Biodiversity; Taxonomy; Animalia; Chordata; Ischnacantiformes; Poracanthodidae; Zemlyacanthus; Zemlyacanthus menneri; October Revolution Island; Severnaya Zemlya
• Online Access: https://doi.org/10.5281/zenodo.11488283; http://treatment.plazi.org/id/B21CD55BFFD4FFEB5A1C8B97FE8924ED

ZEMLYACANTHUS MENNERI (VALIUKEVIČIUS, 1992) (Fig. 3H–J; Table 1; Suppl. 1, figs. 18, 22) Poracanthodes menneri Valiukevičius, 1992, 195, pl. 1-10, text-figs. 1-12. Zemlyacanthus menneri Vergoossen 1997, 45, 46. Type material — Holotype scale LGMTI 35-360; paratypes LGMTI 35-358, 35-355, 35-354, 35-340, 35-341, 35-342, 35-350; Pod’emnaya River, outcrop 67, bed 12, October Revolution Island, Severnaya Zemlya Archipelago, Russia, Severnaya Zemlya Formation (Lower Devonian, Lochkovian). Referred specimens —Scales at levels 513’ (156.4 m), 549’ (167.3 m), 554.5’ (169.0 m), and 556.5’ (169.6 m) in the BC II section, including three scales at 556.5’ (Suppl. 1, fig. 22), and AMF 97961, 97962 (both level 513’= 156.4 m), figured by Parkes (1995, fig. 33.9–33.12): Roberts Mountains Formation. Description —Scales from level 556.3’ (169.6 m) strongly resemble flank scales from the type, articulated specimens of Zemlyacanthus menneri , showing overlapping apposed crown growth zones extending back from close to the anterior margin of the scale crown (Fig.3H–J). This anterior margin lacks well-formed ridges, with just a few short low rounded ridges occasionally present near the middle of the margin. The apposed growth zones forming the crown are denticulated, particularly in the larger more posterior zones, and sometimes comprise lines of slits/overlaps, rather than having uninterrupted overlaps. There is a sharp rim between the neck and base of the scale, with the latter protruding slightly in front of the crown. The convex base and concave neck are of similar heights. Comparison —Some scales represented in the BC II samples closely resemble those from the type, articulated fishes (Valiukevičius 1992, pl. 10) from the Lochkovian of October Revolution Island. Those BC II scales (Fig. 3F, G), tentatively assigned to Gomphonchoporus hoppei (Gross 1947), are similar to some of the smaller scales on the type Z. menneri fish (Valiukevičius 1992, pl. 10.8), and they are found at the same level as the scales readily assigned to Z. ...