Turinia pagei (Powrie, 1870)

Mark-Kurik, Elga, Blieck, Alain, Burrow, Carole J. & Turner, Susan, 2013, Early Devonian fishes from coastal De Long Strait, central Chukotka, Arctic Russia, Geodiversitas 35 (3), pp. 545-578 : 558-560

publication ID	https://doi.org/ 10.5252/g2013n3a3
persistent identifier	https://treatment.plazi.org/id/493F87AA-FF93-6227-689A-FBC4FD84F951
treatment provided by	Marcus
scientific name	Turinia pagei (Powrie, 1870)
status

Treatment

Turinia pagei (Powrie, 1870) ?

( Fig. 7A, B View FIG )

MATERIAL. — Specimens GIT 580-16 and 580-19: scales (the second one lost).

LOCALITY AND STRATIGRAPHIC HORIZON. — Locality (sample) 73, Tonnel’nyj Brook, south of De Long Strait , Chukotka ; Lower Member (1) of Enmakaj Formation, Lochkovian .

DESCRIPTION

Specimen GIT 580-19 View Materials ( Fig. 7A View FIG ) is a mature scale seen here in antero-lateral view, with a high simple elliptical crown, pointed posterior, and a flat topped rounded anterior. ħere are possible minor ridges on the posterior otherwise smooth neck. ħe condition of the scale surface, however, is poorly preserved (see Taphonomy discussion below). ħe deep base has an anterior extension of the base, which might have projected into a longer root. Scale GIT 580- 16 View Materials , seen in lateral view ( Fig. 7B View FIG ), is more typical of a head to cephalopectoral scale with a series of rounded undulations around the gently rounded crown. ħe upper surface is smooth. ħe base is not larger than the crown but extends slightly anteriorward ; it too exhibits slight scalloping in its basal growth around a medium-sized central pulp cavity.

ħese scales are typical of many turiniid head or cephalopectoral scales and are tentatively placed in T. pagei . Alternatively they might belong to Turinia composita Karatajūtė-Talimaa, 2002 or Turinia polita Karatajūtė-Talimaa, 1978 (see below).

Turinia sp. cf. T. composita

Karatajūtė-Talimaa, 2002 ( Fig. 7C, D View FIG )

MATERIAL. — Specimens GIT n° 580-10 and 580-11: scales.

LOCALITY AND STRATIGRAPHIC HORIZON. — Locality (sample) 73, Tonnel’nyj Brook, south of De Long Strait , Chukotka ; Lower Member (1) of Enmakaj Formation, Lochkovian .

DESCRIPTION ħe scale GIT 580-10 View Materials ( Fig. 7C View FIG ) is wide and rhombic with the crown not quite as wide as the base. ħe anterior rim of the crown is gently scalloped into three sections. ħe large flat median part of the crown has two lateral lappet areas which expand posteriorly so that the crown ends in at least five points. A smaller extension to the lower left might be an artifact or a further lower lappet on that side. ħe posterior parts are not well preserved but probably extended well beyond the mid-posterior point of the crown. ħere is a wide shallow grooved neck separating the crown from the relatively shallow base. As the basal view is not available the pulp opening type is unknown. ħe base is slightly thickened anteriorly into a short downwards-projecting narrow spur, which is broken off at the tip. Specimen GIT 580-11 View Materials ( Fig. 7D View FIG ) is generally similar although wider across the scale than in 580-10. ħe projections extend from the median part of the crown as well as being placed on a short narrow lateral lappet or ridge on both sides. ħe extended parts are better preserved and number 9 or 10 with the posterior mid-point. ħe neck is wider and the base slightly shallower ; it extends anteriorly into a short projection. As with the other scale, the basal view is not available and so the pulp opening type is unknown. Within the neck as seen in the lower right of Fig. 7D View FIG there are exposed parts of three fine concentric ridges, which might be evidence of growth lines within the basal tissue (cf. Märss et al. 2007).

ħese two scales with their wide laterally expanded crown with several separate posterior points are comparable with the body scales of Turinia composita (Karatajūtė-Talimaa 2002: fig. 1G, H) and to some extent with some of Turinia barentsia Blom & Goujet, 2002 ( Blom & Goujet 2002: pl. 2). As with the other scales, the surface is severely scoured or etched and opening of dentine and bony aspidine structure can be seen.

Turinia sp. cf. T. polita

Karatajūtė-Talimaa, 1978 ( Fig. 7E View FIG )

MATERIAL. — Specimen GIT 580-17: scale.

LOCALITY AND STRATIGRAPHIC HORIZON. — Locality (sample) 73, Tonnel’nyj Brook, south of De Long Strait , Chukotka ; Lower Member (1) of Enmakaj Formation, Lochkovian .

DESCRIPTION

From the lateral view of this scale, the flat crown can be seen well with the anterodorsal crown rim gently scalloped. ħe crown is smaller than the base with a vertical neck and thin groove around the rim. ħe base is deep and rounded with a small central to offset pulp opening, typical of an older scale where the pulp is overgrown.

ħis is a possible head or cephalopectoral scale and seems most comparable with those of Turinia polita . ħis latter taxon is found in Lochkovian assemblages alongside Turinia pagei in some parts of the Old Red Sandstone Continent (e.g., in Britain: Karatajūtė- Talimaa 1978;Talimaa 2000; ST pers. obs.) whereas in other places seems to appear a little later in the Lochkovian (e.g., Blom & Goujet 2002).