NOTE ON THE FAUNA OF THE KRASNOYARSK SANDSTONES OF THE KUZNETSK BASIN

L. L. Khalfin

Apart from the scanty remains of Upper Permian reptiles characterized by A. N. Ryabinin¹⁾, I know of no other finds of fauna in the Krasnoyarsk sandstones. Therefore the fauna discovered in 1946 by the tireless investigator of Kuzbass, V. I. Yavorsky, in these deposits on the Tom River near the village of Smolino (approximately 25 km in a straight line southwest of Kemerovo) is of great interest, and I give below a characterization of the specimens delivered to me, although this fauna is meager, poorly (and in part quite unsatisfactorily) preserved, and in most cases does not permit any fairly precise determinations.

Specimen 1 f. (right bank of the Tom River, 2 km below the mouth of the Spuskovaya River). Two small hand specimens; one of them is a piece of gray, uneven- and coarse-grained sandstone with charred fragments of plants and very small ostracods with a highly lustrous, morphologically very simple shell; here also are two problematic formations: a) one of them is a small fragment of a cylindrical body with a diameter slightly greater than 1 mm; the cylinder is composed of a brownish-brown mass, apparently of carbonate-clayey composition; along the axis of the cylinder there was a very thin cavity, now filled with a white substance (calcite?); apparently this is an inorganic formation of the “crane-neck” type; b) the second, in its general habitus, may be taken for the nucleus of a small (3 mm in length) right valve of a pelecypod shell of the modiomorphid type, but, possibly, it too is of inorganic nature.

The second hand specimen consists of fine-grained, bedded, brown-gray sandstone with the same fragments of plants and very small lustrous ostracod shells; in addition to them, there is here one poorly preserved, but still distinguishable, pelecypod specimen of the Kolchugino type, which cannot be determined more precisely than Microdontella (?) sp.

Specimen 12 f. (right bank of the Tom River, 5 km below the mouth of the Spuskovaya River). Red-brown marl with charred plant remains, small ostracods, and poorly preserved, crushed pelecypods of the Kolchugino type; two specimens are preserved better than the others, but even they can be determined only very approximately—as? “Microdontella subovata (Jones).”

Specimen 13 f. (right bank of the Tom River, opposite B. Kedrovy Island). Dense gray carbonate rock with small problematic organic remains; here also is an incomplete imprint of an insect wing.

Specimen 14 f. (right bank of the Tom River opposite the middle of B. Kedrovy Island). Dark-gray, with a brown coating, fine-grained bedded sandstone; one of the planes of its bedding is entirely strewn with crushed small shells of rounded outline; only isolated specimens have been preserved—

¹⁾ On the discovery of remains of Theriodontia in the coal-bearing series of deposits of the Kuznetsk Basin. Izvestiya VGRO, vol. L, 1932, issue 82.

only better than the others. These shells may belong to small pelecypods of the type Microdonta pumilia Khalf. (from the Ilyinskaya suite), but to an even greater degree they resemble shells of estheriids. In the same bed there occur, very rarely, crushed shells of somewhat larger size, probably belonging to the species Microdontella subovata (Jones), common in the Kolchugino fauna. Finally, in this same bed there is present a small fish bone of spear-like outline, broken off at the blunt end.

Under the same number there is a small piece of a more fine-grained red-brown, clayey-marly rock with extremely indistinct impressions of pelecypods: only under strong illumination and when the specimen is slowly turned in different directions can one catch the moment when the faintly gleaming surface of the impressions stands out slightly against the general background; then it can be established that these specimens had submitiloid outlines, dimensions—up to 8 mm along the principal diagonal—and possessed fine concentric growth marks; these specimens may be called Anthraconauta sp.

Specimen 21 f. (right bank of the Tom River, 0.6 km below the village of Smolino). Pieces of gray and brown sandstone with rare ostracods and pelecypods; among the latter there are fairly large (up to 12 mm in length) specimens of Microdonta microdonta (Khalf.); one small specimen of this species is the best preserved in the entire collection.

Specimen 22 f. (right bank of the Tom River, 0.7 km below the village of Smolino). Sandstone, similar to the preceding one, with a mass of small lustrous ostracods, the same as in specimen 1 f., and with fragments of valves of rather large pelecypods, apparently microdontellas.

The characterization given above of the fauna found by V. I. Yavorsky, despite its meagerness and imperfection, permits certain conclusions to be drawn. First of all I wish to emphasize that the fauna was found in a whole series of points or, in any case, in a whole series of beds of some large section. Apparently, this permits us to say that the conception of the Krasnoyarsk sandstones as deposits almost devoid of fauna is erroneous, and that further searches for organic remains in these sandstones may be crowned with complete success. In this connection it is necessary to stress the diversity of this fauna: in its composition, despite the small quantity of material delivered, representatives of lamellibranch mollusks, two orders of crustaceans (ostracods and phyllopods), insects, and fish have been discovered. This diversity further broadens the prospects of possible finds; if we recall that it is precisely in the Krasnoyarsk sandstones that the as yet only find in Kuzbass of reptile bones has been made, then we shall be entitled to think that perhaps within the one-and-a-half-kilometer thickness of these sandstones there is still an undiscovered fauna concealed, richer and more diverse than in any other deposits of the basin. The poor preservation of the fauna found near the village of Smolino, of course, can in no way mean that all the rest of the fauna of the Krasnoyarsk sandstones has necessarily been preserved just as poorly; moreover, within the Smolino fauna the pelecypods and estheriids are especially poorly preserved; the ostracod shells are preserved no worse than in other Kolchugino deposits, and the impression of the insect wing is distinct, though, unfortunately, incomplete.

Turning to the pelecypods of this fauna, we can establish with complete obviousness their Kolchugino type. The predominant forms, which, despite all the imperfection of their preservation, may be assigned to the species Microdontella subovata (Jones) and Microdonta microdonta (Khalf.)—the most widespread and common species of the Kolchugino fauna; anthraconautas are also present, but the material collected is insufficient for their determination. As I have established elsewhere, the Kolchugino fauna first

appears in the very uppermost parts of the Kuznetsk suite, in the Tersian horizon of the latter, while still having an archaic character in this horizon. The microdontids of the Smolino fauna (Fig. 21 ф.) are of rather large size and in all respects are similar to representatives of this genus from the Ilyinskaya and Yerunakovskaya suites. More precise comparisons of the Smolino fauna with the fauna of the Ilyinskaya and Yerunakovskaya suites are at present impossible.