NEW MATERIALS ON THE STUDY OF UPPER PALEOZOIC WOODS OF THE KUZBASS

M. D. Parfenova

(Presented by Prof. L. L. Khalfin)

The material for the present work was a collection of fossil-wood specimens gathered by the author in 1952–1953 in the Leninsk-Kuznetsk district of the Kuzbass, in deposits of the Kolchugino Series. Some of these specimens were studied in thin sections. From the other part, cellulose films were prepared by the method of J. Willis and Leise [6].

Each specimen was studied in three sections: transverse, radial, and tangential. Altogether we studied about one hundred preparations. The material on the fossil woods studied will be presented in a series of articles; the present article is the first.

The beginning of the study of Upper Paleozoic woods dates to 1845, when Goeppert [2] first described the plant Araucarites Tchihatcheffianus. These were specimens of fossil trunks lacking bark, collected on the right bank of the Inya River in the Kuznetsk Basin.

The genus Araucarites Presl was created by its author for imprints of branches externally resembling living araucarias, and not for woods resembling the wood of these plants. Since the foliage of these fossil forms was unknown and could have been quite different from the foliage of araucarias, Goeppert’s use of the name Araucarites for this wood was incorrect. Taking this circumstance into account, Endlicher [7], in his synopsis for similar fossil woods, created the genus Dadoxylon. To this genus he also assigned the species Araucarites Tchihatcheffianus Goeppert. Similar historical data on the study of fossil woods were given by M. D. Zalessky in 1911. In that work he gives a detailed description of the species Dadoxylon Tchihatcheffi Goeppert, based on the study of eleven specimens from the Kolchugino Series of various districts of the Kuzbass.

The specimens studied by M. D. Zalessky are pieces of wood without any traces of bark. The pith was not preserved in all specimens. In describing the secondary xylem, M. D. Zalessky notes the excellent visibility of the annual rings. This discovery was of interest: Dadoxylon Tchihatcheffi is undoubtedly a Permian plant, and at that time it was in no way supposed that such sharp seasonal temperature fluctuations existed in the Permian as to make the formation of annual rings possible.

From the phylogenetic point of view, according to M. D. Zalessky, Dadoxylon Tchihatcheffi represents the last step of the mesarch bundle of the primary

wood during its transformation into endarch wood in Paleozoic stems. M. D. Zalessky was inclined to regard this species as an extreme member of the group of stems of the Dadoxylon type.

The genus Dadoxylon was established on the basis of such features of the secondary wood as are characteristic of various plants (Erystophyton, Pitys, Cordaites, etc.). M. D. Zalessky observed in wood from the Permian of the Kuzbass a number of other characters, which enabled him, for the species Dadoxylon tchihatcheffi, to establish the genus Mesopitys. To this genus he proposed assigning plants with secondary wood of the “Dadoxylon” type, with a fasciculate arrangement of the weakly developed primary xylem of endarch or mesarch structure, and with an obviously single bundle traversing the secondary wood. For woods of the “Dadoxylon” type in which the bundle traversing the secondary wood is double (Dadoxylon spenceri), M. D. Zalessky proposed the generic name Parapitys. The genus Dadoxylon itself remains for wood whose affiliation with the genera Cordaites, Mesopitys, and Parapitys has not been proven.

There is also the species Dadoxylon Trifilievii Zal., described by M. D. Zalessky [9] from the Upper Devonian deposits of the Donbass. Later the same author came to the conclusion that it must be separated into a special genus—Calilixylon.

In 1918 M. D. Zalessky, together with microphotographs of the anatomical structure of the leaf Noeggerathiopsis aequalis Goeppert, presented several images of the anatomical structure of Mesopitys Tchihatcheffi from the Kuzbass.

In 1927 M. D. Zalessky gave illustrations of twenty-five species belonging to ten genera of fossil woods from various localities of the European part of the Soviet Union, chiefly the Cis-Urals and Pechora.

In 1935 M. D. Zalessky described a new species of wood, Metacaenoxylon carpentieri Zal., from the Kuzbass. The author pointed out the great similarity of the described species to Caenoxylon scotti Zal. from the Lower Permian of the Cis-Urals. Having studied the structure of the wood of the Kuznetsk specimen, M. D. Zalessky came to the conclusion that Metacaenoxylon carpentieri is a later Upper Permian descending phylogenetic branch of the wood Caenoxylon Scotti.

In the same source, but in another paper, M. D. Zalessky [11] describes the wood of a new fern from the family Osmundaceae, Jegosigopteris javorskii Zal., from the Kolchugino Series of the Kuzbass. Comparing this species with other representatives of various genera of fern woods from the Cis-Urals and Pechora, the author concludes that the new plant is of Upper Permian age.

If to the material set forth above one adds M. D. Zalessky’s essay on the question of coal formation [3], where several photographs with images of fossil woods and a description of the wood Dadoxylon amadokense Zal. [12] from the Donets Basin are given, then one may say that this is a more or less complete list of those studies that were carried out on the Upper Paleozoic woods of the Soviet Union.

Recently a note by V. V. Besedin [1] appeared concerning the discovery of a fragment of a tracheid wall in Middle Proterozoic deposits of Krivoi Rog. The tracheid remnant, described under the name Ingulecixylon silicitorasuin Besedin, has bordered pores of the abietoid type and belongs, in the opinion of the author who described this specimen, to the secondary xylem of a gymnospermous plant, probably a conifer, closest to the family Pinaceae.

Despite the fact that the history of these studies extends over more than a hundred years, our information on the Upper Paleozoic woods of the USSR is extremely scanty; this is especially true of the Kuznetsk Basin, where only ...

Plate II

Fig. 1. Transverse section ×120. Spring tracheids, indistinct boundary of the annual ring, and autumn tracheids.
Figs. 2–5. Radial section ×120.
Fig. 2. Curved tracheids and their ends.
Fig. 3. Medullary ray and simple oval pores on the cross-fields.
Fig. 4. Tracheids with transverse septa and bordered pores. Simple pores on the cross-fields.
Fig. 5. Bordered round pores in the tracheids.

three species (Mesopitys tchihatcheffi Goepp., Metacaenoxylon carpentieri Zal., Jegosigopteris javorskii Zal.) of woods from Permian deposits.

The principal works in this field belong to M. D. Zalessky; unfortunately, his most substantial studies lack text and are presented only as an atlas. This circumstance considerably hinders the use of his works. As for Zalessky’s works that do contain text, it should be noted that, besides detailed descriptions of new species, they provide detailed comparisons with already known species, present considerations on the phylogenetic relationships of these plants, and often include conclusions on their stratigraphic significance.

The above review of works on Paleozoic woods shows the importance of their study both from the standpoint of further clarification of the composition of our flora and from the standpoint of reconstructing the phylogenetic relationships of individual groups of plants and using them in stratigraphy.

Genus Kuzbassoxylon gen. nov.

Macroscopically the annual rings are expressed; their width is 8–10 mm, and the ring boundary is fairly distinct. Under the microscope, however, the boundary of the annual ring is distinguished with difficulty; it is indistinct and wavy. In radial section, the pits in the tracheids are bordered, large, round or slightly elongated in width; they are arranged in 1–2 rows in the tracheids, either slightly touching one another or separated. In the cross-fields the pits are simple, rounded-quadrangular, oval, or lenticular, arranged singly in the field.

The medullary rays in tangential section are abundant, consist of 4–60 cells, are uniseriate, biseriate, or triseriate, often wavy and, joining with one another, frequently form loops and branches.

Remarks. The genus is distinguished by the distinctive character of the pits and the structure of the medullary rays.

Distribution. Kuzbass, Leninsk-Kuznetskii district. Nikitinskoe deposit; Kolchugino Series.

Kuzbassoxylon leninskiensis sp. nov.

Tables I, II

Holotype. Collection of the Tomsk Polytechnic Institute, specimen no. 21. Kuzbass, Leninsk-Kuznetskii district. Nikitinskoe deposit, borehole 2441, depth 292, 0.5 m. Kolchugino Series.

Transverse section. Macroscopically the annual rings are expressed; their width is 8–10 mm, and the ring boundary is fairly distinct. Under the microscope the cells within a single annual ring differ little in size. Their shape is rounded-polygonal, quadrangular, square, with straight or slightly sinuous, thick walls. Cell dimensions are 32.5–81.2 × 42–81.2 µ; the cell wall is up to 13 µ thick and more. The spring cells are more often square, sometimes somewhat elongated in the radial direction. Only at the very end of the annual ring do the cells decrease somewhat in size (17.4–23.4 × 23.4–29.2 µ), become compacted, and assume the form of more sharply defined quadrangles, slightly compressed in the radial direction. However, the boundary of the annual ring is distinguished with difficulty under the microscope; it is indistinct and sinuous.

The medullary rays are frequent and short; a few extend for half the width of the ring. At the boundary of the annual layer there are 7–10 rays across the diameter of the microscope field. The rays are straight or slightly sinuous, run rectilinearly, and at the ring boundary bend only barely perceptibly.

Plate I

Fig. 2, 3. Tangential section × 120. Visible medullary rays of the annual ring.

Fig. 2, 3. Tangential section × 120. Visible medullary rays and formations resembling resin canals.

Radial section. Tracheids 17.4–58 μ wide, with thick sinuous walls; they themselves are often bent in a wavelike manner. The ends of the tracheids are bluntly rounded or slightly pointed and, as a rule, somewhat curved. Transverse partitions are sometimes observed on the tracheids. The medullary rays are high, consisting of elongated cells, which are more often quadrangular; sometimes the partitions between the ray cells are oblique. Where the rays intersect the tracheids, even square or quadrangular fields are obtained, and in each such field there is one large simple pore. The height of the ray cells is 17.4–23.4 μ, their length 63.8–92.8 μ. In the cross-fields the pores are simple, one in each field; their shape is rounded-quadrangular, but more often oval or lenticular, and they are arranged along the diagonal of the field; in the latter case the pores of a single ray are oriented predominantly in the same way. The dimensions of the simple pores are 23.4–34.8 μ along the line of greatest length.

In the tracheids the pores are bordered, round, and large. Very rarely the pores may be barely noticeably elongated across the width of the tracheid. The pores are arranged in the tracheids in one row, more rarely in two rows, slightly touching one another, and sometimes even at some distance from one another. The pores have a diameter of 11.6–23.4 μ. The pore apertures, up to 11.6 μ along the line of greatest length, are usually round, more rarely oval, and are oriented transversely or obliquely relative to the tracheid.

Tangential section. Tracheids 17.4–58 μ wide, with even or slightly sinuous walls, have, as a rule, shortly pointed ends. In the main mass the tracheids are long, but among the narrowest tracheids shortened ones are also observed. Along their length the tracheids are more often irregularly wavy-curved. The medullary rays are abundant. In the field of view of the microscope 18–25 rays are counted. The impression of an abundance of rays is created not only by their number, but also by their character: the main mass of rays is very long, consisting of 20–30 cells, but rays of 4–60 cells occur. The ray cells are round and, more rarely, slightly elongated in width. The dimensions of the ray cells are 11.6–34.8 μ in diameter or along the line of greatest length. The short rays are rectilinear, the long ones slightly wavy, and not infrequently individual parts of different rays join with one another and form branched or loop-shaped rays. The main mass of rays is uniseriate, but biseriate and triseriate rays occur; moreover, the multiseriate character of a ray characterizes not its entire length, but some section in the middle, while the ends are uniseriate. Such rays have, to some degree, a spindle-shaped or lens-shaped form.

In the section there occur lens-shaped formations consisting of a group of rounded, polygonal, or irregularly shaped cells, 23.4–58 μ in size along the greatest diameter, which are arranged around a small, irregularly rounded or slit-like cavity. It is thought that these formations should be regarded, if not as resin canals, then as their primordia. Round pores sometimes show through very indistinctly in the wall of the tracheid.

Remarks. In the character of the pores and their arrangement, as well as in the structure of the medullary rays, this species differs from all species of Upper Paleozoic woods known to us.

Occurrence. Kuzbass, Nikitino deposit, borehole 2441, depth 292, 0.5 m. Kolchugino Series.

LITERATURE

1. Bessedin V. V. A fragment of a tracheid wall from the Precambrian rocks of Krivoy Rog. Collection of scientific works of the Krivoy Rog Mining Institute, issue VIII, 1960.

2. Zalessky M. D. Études anatomiques: Dadoxylon Tchihatcheffi, Goeppert sp. Transactions of the Geological Committee, new series, issue 68, 1911.

1. Zalessky, M. D. Essay on the question of the formation of coal. Publ. Geological Committee, Petrograd, 1914.

2. Zalessky, M. D. Paleozoic flora of the Angara series. Atlas, Transactions of the Geological Committee, new ser., issue 174, 1918.

3. Zalessky, M. D. Permian flora of the Ural margins of Angarida. Atlas, Transactions of the Geological Committee, new ser., issue 176, 1927.

4. Sveshnikova, I. N. Ref. Joyce, Willis, Leitch. Rapid technique for obtaining cellulose films in paleobotany. 1956, 20, No. 80, 635–637 (Engl.). Referativnyi zhurnal, No. 10, 1958.

5. Endlicher. Synopsis Coniferarum. 298, 1847.

6. Tchihatcheff. Voyages scientifique dans l’Altai Oriental et les parties adjacentes de la frontière de Chine. Paris, 1845.

7. Zalessky, M. D. Communication préliminaire sur un nouveau Dadoxylon à faisceaux de bois primaire autour de la moelle, provenant du dévonien supérieur du bassin du Donetz.

8. Zalessky, M. D. Sur un bois Metacaenoxylon carpentieri Zal. du terrain permien supérieur du bassin de Kousnetzk.

9. Zalessky, M. D. Structure anatomique du stipe d’un nouvelle osmondee du terrain permien du bassin Kousnetzk.

10. Zalessky, M. D. Sur quelques végétaux fossiles nouveaux des terrains carbonifères et permiens du bassin de Donetz.