Zemlyacanthus

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 (1975), pp. 1-32 : 9

ZEMLYACANTHUS VERGOOSSEN, 1997

Type species — Poracanthodes menneri Valiukevičius, 1992 .

Remarks —The pore canal system in Z.menneri scales is of the punctatiform type sensu Vergoossen (1997), with both arcade and radial pore canals ( Valiukevičius 1992), but the scales differ from those of Poracanthodes and Radioporacanthodes in having only appositional growth zones forming the posterior crown, and canals opening out on the surface in long slits parallel to the denticulated posterolateral edges. In scales of Poracanthodes the canals open out through rows of small pores with the same alignment, and in Radioporacanthodes through slits or large pores in radiating rows above the radial canals. Gomphonchoporus scales with pore canal systems are porosiform. For these reasons, and because it is the only poracanthodid species known from articulated fish, Ver- goossen (1997) erected the new genus Zemlyacanthus . Here we recognise the validity of this genus, based on the features listed here.