Zemlyacanthus menneri, (VALIUKEVICIUS, 1992), VERGOOSSEN, 1997

Burrow, Carole Jan, Murphy, Michael & Turner, Susan, 2023, Late Silurian to earliest Devonian vertebrate biostratigraphy of the Birch Creek II section, Roberts Mountains, Nevada, U. S. A., PaleoBios 40 (4), pp. 1-32 : 9-10

publication ID

https://doi.org/ 10.5070/P940454153

publication LSID

lsid:zoobank.org:pub:58312615-0833-432E-BF5D-3DFFBF361AAA

DOI

https://doi.org/10.5281/zenodo.11488283

persistent identifier

https://treatment.plazi.org/id/B21CD55B-FFD4-FFEB-5A1C-8B97FE8924ED

treatment provided by

Felipe

scientific name

Zemlyacanthus menneri
status

 

ZEMLYACANTHUS MENNERI ( VALIUKEVIČIUS, 1992)

( Fig. 3H–J View Figure 3 ; Table 1 View 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 View Figure 3 ). 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 View Figure 3 ), 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. menneri. Overlap of scale morphotypes between different taxa is a common problem in taxonomy based on isolated scales, particularly when samples are rich in taxa but poor in numbers. Also, recognition that both scales with and without a pore canal system can belong to a poracanthodid species (e.g., Vergoossen 1999a, Burrow 2013) further complicates taxonomic assignments.

Kingdom

Animalia

Phylum

Chordata

Order

Ischnacantiformes

Family

Poracanthodidae

Genus

Zemlyacanthus

Loc

Zemlyacanthus menneri

Burrow, Carole Jan, Murphy, Michael & Turner, Susan 2023
2023
Loc

Poracanthodes menneri Valiukevičius, 1992

Valiukevicius 1992
1992
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