Kettnerites (K.) huberti, Szaniawski & Drygant, 2014

Szaniawski, Hubert & Drygant, Daniel, 2014, Early Devonian scolecodonts from Podolia, Ukraine, Acta Palaeontologica Polonica 59 (4), pp. 967-983 : 974-978

Genus “ Kettnerites ” Žebera, 1935

Type species: Kettnerites kosoviensis Žebera, 1935 , Bohemia; Silurian .

Remarks.—Status of the genus is uncertain. The holotype of its type species Kettnerites kosoviensis Žebera, 1935 has been inaccessible” for Šnajdr (1951: 243, English translation), who gave “a new diagnosis of the genus” (1951: 259) and was not found” by Tonarova (2008: 188), who published revision of the genus. The only illustration of the holotype published by Žebera (1935: fig. 7) shows a singular, most probably deformed right MI or MII, which based on the illustration is not determinable. Another species assigned by the author to the same genus— K. depressus Žebera, 1935 (pl. 2: 8) probably represents a left MII and is somewhat similar to those elements in paulinitids but different from all hitherto known. Moreover the typical MI and MII of Kettnerites, sensu Šnajdr (1951) , were assigned by Žebera (1935: fig. 2, pl. I:

–5) not to Kettnerites , but to Arabellites Hinde, 1879 , what means that his concept of the genus Kettnerites was different from that of Šnajdr (1951). Also the differences between the genera Kettnerites and Paulinites Lange, 1947 are not well defined. Kielan-Jaworowska (1966: 125) was in the opinion that they are insignificant and regarded Kettnerites as “... a junior subjective synonym of Paulinites Lange ”. Another opinion was expressed by Bergman (1989: 49), who widely used the name Kettnerites in his monograph of the Silurian paulinitids from Gotland and stated that “... none of the European species belong to Paulinites ”. However, he did not substantiate this conclusion. In our opinion formal status of the genus Kettnerites Žebera, 1935 is uncertain and should be clarified but it is out of the scope of the present paper. Therefore we use the name with quotation marks.

In older literature elements similar to MI of paulinitids were usually assigned to Nereidavus Grinnel, 1877 , but the genus is not valid because the holotype of its type species N. varians Grinnel, 1877 was incompletely preserved and became damaged ( Jansonius and Craig 1971). The above cited authors proposed to establish new genus Nereigenys Jansonius and Craig, 1971 “to accommodate all forms traditionally assigned to Nereidavus ” ( Jansonius and Craig 1971: 274). However, the type species proposed by them—the Nereigenys disjunctus ( Eller, 1963) belongs in our opinion to Paulinites or Kettnerites . For discussion of the problem see also Eriksson (1999).

In the Lower Devonian deposits of Podolia the jaws of “ Kettnerites ” are most abundant and diversified. Over 250 comparatively well preserved elements were found, but because of their wide intraspecific variability and infrequency of individual elements in samples, not all of them can be determined to the species level. The more that in many samples elements of different species occur. All the three recognized here species were hitherto known from the Silurian of the Baltic region only.

“ Kettnerites ” huberti Bergman, 1987

Fig. 6A–G.

1970 Paulinites polonensis Kielan-Jaworowska, 1966 ; Szaniawski 1970: 465–466, pl. 1: 5A–D.

1987 Kettnerites (K.) huberti nov. sp.; Bergman 1987: 59–62, figs. 13R–U, 18, 34–36.

1989 Kettnerites (K.) huberti Bergman, 1987 ; Bergman 1989: 65–70, figs. 18D, 34–36.

Material.—20 right MI, one of them with preserved basal plate, 22 left MI, 24 right MII, 25 left MII ( ZPAL.Sc.8/4.13, 5.8, 7.3, 7.7, 7.10, 9.2, 12.1), samples S.Ust.1, S.Sy.3, S.Vy.3, S.Za.4, S.I.Z.13, 16, 17. Elements of the species occur in the almost whole Lower Devonian sequence of Podolia, except the lower part of the Borshchiv Horizon ( Fig. 2 ).

Remarks.—The Early Devonian specimens do not differ significantly from the hitherto known Silurian forms. Most specimens of both MIs have an inner margin characteristic for the species, which is usually concave in the anterior part and slightly convex in the posterior part. Their denticles are usually much bigger in the posterior part. The fang is comparatively large and has well developed cutting edge. Basal plate is about 8 times shorter than the jaw, is nearly square shaped and only its inner basal portion is extended poste-

Fig. 6. SEM micrographs of paulinitid scolecodonts from Lower Devonian of Podolia: Ivanye Horizon, section 58 (E, L–N, R, T), section 73 (O, P), section → 76 (A, C, D, F, H–J, S); Chortkiv Horizon, section 56 (B, K), section 70 (G); upper part of Borshchiv Horizon, section 92 (U, V). A–G. “ Kettnerites ” huberti Bergman, 1987 . A, B. Left M 1 in dorsal view. A. ZPAL Sc.8/7.3, sample S. IZ.16. B. ZPAL Sc.8/4.13, sample S.Bo.3. C. ZPAL Sc.8/12/1, sample S. IZ.13, left M 1 in ventral view. D. ZPAL Sc.8/7.10, sample S. IZ.16, right MII in dorsal view. E. ZPAL Sc.8/7.7, sample S. IZ.16, left MII in dorsal view. F, G. Right MI in dorsal view. F. ZPAL Sc.8/9.2, sample S. IZ.17. G. ZPAL Sc.8/5.8, sample S.Vy.3. H–L. “ Kettnerites ” martinssonii Bergman, 1987 . H. ZPAL Sc.8/8.23, sample S. IZ.16, left MI in dorsal view. I. ZPAL Sc.8/1.1, sample S.Za.4, right MI in ventral view. J. ZPAL Sc8/1.5, sample S.Za.1, right MI in dorsal view.

K. ZPAL Sc.8/4.16, sample S.Sy.3, right MII in dorsal view. L. ZPAL Sc.8/10.9, sample S.Za.12, left MII in dorsal view. M, N. “ Ketttnerites ” sp. A, right

MI in dorsal view. M. ZPAL Sc.8/10.10, sample S.Za.11. N. ZPAL Sc8/10.15, sample S.Za.11. O–U. “ Kettnerites ” polonensis Kielan-Jaworowska, 1966 .

O. ZPAL Sc.8/6.4, sample S.Do.5, left MI in dorsal view. P. ZPAL Sc.8/6.19, sample S.Do.1, right MI in ventral view. Q. ZPAL Sc.8/1.10, sample S.Za.1, left MII in dorsal view. R. ZPAL Sc.8/7.20, sample S. IZ.18, right MII in dorsal view. S. ZPAL Sc.8/1.4; sample S.Za.1, left MI in dorsal view. T. ZPAL Sc.8/3.7, sample S.Usty.2, right MI in dorsal view. U. ZPAL Sc.8/3.8, sample S.Usty.2, incomplete right MI in right lateral view.

riorly. Basal plate of the species was hitherto known only from one joined jaw apparatus ( Szaniawski 1970). Right MII has two precuspidal denticles, narrow ramus directed postero-laterally, posterior part of the jaw long and bluntly ended. Left MII have one precuspidal denticle. Denticles of the anterior part of inner margin much smaller than those of the posterior part.

Jaws of “ K. ” huberti , similarly as elements of other paulinitids, are morphologically variable and only the well preserved specimens can be identified to the species level. The uppermost hitherto known stratigraphic range of the species was Upper Ludlow.

“ Kettnerites ” martinssonii Bergman, 1987

Fig. 6H–L.

1960 Paulinites sp. ; Martinsson 1960: 5–6, fig. 1: 6. 1987 Kettnerites (K.) martinssonii n. sp.; Bergman 1987: 62–66, figs.

12A–G, 18, 37–40.

Material.—3 right MI, 2 left MI, 3 right MII, and 4 left MII ( ZPAL Sc.8/1.1, 1.5, 4.16, 8.23, 10.9), samples S.Sy.3, S.I.Z.16, S.Za.1, 4, 12 from the Chortkiv and Ivanye horizons; Middle Lochkovian, Lower Pragian, Podolia.

Remarks. —Shape of both MI and MII correspond to the description of Bergman (1987, 1989). Denticles of both MI slightly spaced in the anterior part. Shank of right MI sharply pointed. Right MII with one large precuspidal denticle and wide ramus. Left MII with wide shank and a series of characteristic, comparatively short and nearly equal in size, anterior denticles.

“ Kettnerites ” polonensis ( Kielan-Jaworowska, 1966)

Fig. 6O–U.

1966 Paulinites polonensis n. sp.; Kielan-Jaworowska 1966: 126–129, figs. 5L, 11, pl. 29, pl. 30: 7, 8.

1980 Paulinites polonensis Kielan-Jaworowska, 1966 ; Wolf 1980: 86–87, pl. 12: 102–104.

1989 Kettnerites (K.) polonensis ( Kielan-Jaworowska, 1966) ; Bergman 1989: 66–69, pls. 42–44.

Material.—4 right MI, 6 left MI, 7 right MII, 5 left MII ( ZPAL Sc.8/1.4, 1.10, 3.7, 3.8, 6.4, 6.19, 7.20), samples S.Usty.2, S.Do.1, S.I.Z.18, S.Za.1, 5. Elements of this species occur in almost whole Lower Devonian sequence in Podolia except of the lower part of the Borshchiv Horizon.

Remarks.—The Lochkovian specimens from Early Devoni- an do not differ much from those described from the Silurian erratic boulders from Poland ( Kielan-Jaworowska 1966) and Silurian of Gotland Island ( Bergman 1989). Both MI are very long and have inner and outer margins nearly parallel but the inner one is slightly concave in the anterior part while the outer one in the posterior part. Denticulation of the margins differentiated but in most specimens the denticles are longer in the anterior part. The short spine protruding from the posterior part of outer margins of both MI, characteristic for type material of the species, is not well developed in any of the MIs from Podolia. Right MII has two precuspidal denticles and narrow ramus. Denticles of their inner margin are biggest in the middle part. Left MII have one precuspidal denticle. Denticles of the inner margin are biggest below its middle.

“ Kettnerites ” sp. A

Fig. 6M, N.

Material.—2 right MI ( ZPAL Sc.8/10.10, 10.15), sample S.Za.11, section 58, from upper part of Ivanye Horizon, Pragian, Podolia.

Remarks.—Jaws wide and comparatively short. Inner margin nearly straight with denticles short and rounded. Fang thick, directed medially. Inner wing narrow, tapering posteriorly. Shank short. They differ from all other right MI of the collection by bigger width, nearly straight inner margin and rounded denticles.

“ Kettnerites ” spp.

Fig. 7H, M–O .

Material.— 42 specimens of left MIII (= unpaired element) ( ZPAL Sc.8/6.6, 6.7, 11.5, 11.13), samples S.Do. 6, S.I.Z.12 18 from different levels of the whole Lower Devonian sequence of Podolia .

Remarks. —Determination of the detached left MIII to the species level, based on their morphology only, is presently not possible because our knowledge of the elements is still comparatively poor. The unpaired MIII of the genus are known from two joined jaw apparatuses of the “ Kettnerites ” polonensis , described by Kielan-Jaworowska as Paulinites polonensis (1966: pl. 29: 2, 3) and “ K. ” huberti described by Szaniawski (1970: pl. 1: 5) also as Paulinites polonensis . Besides they are known as detached elements of K. bankvaetensis Bergman, 1987 , K. sisyphi klasaardensis Bergman, 1987 , and K. siaelsoeensis Bergman, 1987 . However the specimens from Lochkovian of Podolia differ from those of the earlier described species in outline and denticulation. Possessed elements cannot be determined also based on numerical data because of small number of well preserved specimens in individual samples.

All left MIII in our collection have 8 or 9 denticles and in all but one the third denticle is the biggest. The longitudinal branch in lateral view is triangular and tapers posteriorly.The ramus is narrow, sharply pointed, directed nearly perpendicularly to the longitudinal branch. In some specimens the outer margin of the ramus in lateral view is concave. The jaws are somewhat similar to corresponding elements of Paulinites paranaensis Lange, 1947 named “unpaired piece” in English translation of the paper ( Lange 1949: pl. 11: 1–12).

“ Kettnerites ”? spp.

Fig. 7A–D .

Material. — Mandibles, 6 specimens ( ZPAL Sc.8/8.7, 8.19, 10.6, 11.14), samples S.I.Z.2, 13, 16, S.Za. 2, 12, all from the Ivanye Horizon, Pragian, Podolia .

Remarks. —Co-occurence of the mandibles with numerous jaws of “ Kettnerites ” strongly suggests that they belonged to apparatuses of the same genus. Their paulinitid origin is suggested also by their morphological similarity to the mandibles of Paulinites paranaensis Lange. In some of them similar denticulation of the anterior margin is preserved also see Lange 1949: pl. 7: 1, 4, 10).

“ Kettnerites ”? spp.

Fig. 7I–L .

Material. — 18 specimens of left and right MIV (named also paragnaths) ( ZPAL Sc.8/6.15, 7.13, 8.8, 8.22), samples S.Do. 2, S.Z.6, 13, 18, from different stratigraphic levels of Upper Lochkovian and Lower Pragian, Podolia .

Remarks. —The anterior elements of fossil jaw apparatuses are rarely described. They are seldom well preserved because of small size and fragility. Of the paulinitids the elements are known only in P. paranaensis ( Lange, 1947) , “ K. ” polonensis ( Kielan-Jaworowska, 1966) and “ K. ” sisyphi klasaardensis ( Bergman, 1987) . The elements found in Podolia are rather poorly preserved. In lateral view they are plate-like, partly rounded, with inner margin denticulated. Most of them have 6 to 8 denticles which gradually decrease in size posteriorly. They differ from the corresponding elements of polychaetespids (see Fig. 5I–L ) mainly by the larger number of denticles and narrower opening of the pulp cavity. Their specific determination is in present state of knowledge not possible.

Figures

Fig. 2. Stratigraphic ranges of the described scolecodonts. Section numbers as in Fig. 1.

Fig. 7. SEM micrographs of selected elements of paulinitid scolecodonts and undetermined anterior elements from Lower Devonian of Podolia: Ivanye Horizon, section 58 (D, O), section 73 (M, N, K), section 76 (A–C, E, G–J, L); Chortkiv Horizon, section 70 (F). A–D. “Kettnerites”? spp. A, B. Left mandibles in dorsal view. A. ZPAL Sc.8/8.19, sample S.IZ.13. B. ZPAL Sc.8/11.14, sample S.Za.2. C, D. Right mandibles in dorsal view. C. ZPAL Sc.8/7.1, sample S.IZ.16. D. ZPAL Sc.8/10.6, sample S.Za.12. E. Family uncertain, gen. et sp. indet.A, ZPAL Sc.8/7.9, sample S.IZ.16, in lateral view. F. Family uncertain, gen. et sp. indet. B, ZPAL Sc.8/4.22, sample S.Zo.4, in lateral view. G. Family uncertain, gen. et sp. indet. C, ZPAL Sc.8/7.18, sample S.IZ.18, in lateral view. H, M–O. “Kettnerites” spp. left MIII. H. ZPAL Sc.8/11.5, sample S.I.Z.18, in dorsal (H 1) and left lateral (H 2) views. M. ZPAL Sc.8/6.6, sample S.Do.6, in right lateral (M 1) and dorsal (M 2) views. N. ZPAL Sc.8/6.7, sample S.Do.6, in left lateral (N 1) and dorsal (N 2) views. O. ZPAL Sc.8/11.13, sample S.Za.12, in left lateral (O 1) and dorsal (O 2) views. I–L. “Kettnerites”? spp. left and right MIV. I. ZPAL Sc.8/7.13, sample S.IZ.18, right element in ventral lateral view. J. ZPAL Sc.8/8.22, sample S.I.Z.13, right element in ventral lateral view. K. ZPAL Sc.8/6.15, sample S.Do.2, left element in dorsal lateral view. L. ZPAL Sc, 8/8.8, sample S.IZ.6, left element in ventral lateral view.

Fig. 5. SEM micrographs of polychaetaspid scolecodonts from Lower Lochkovian of Podolia, lower part of Borshchiv Horizon, section 48, sample S.Kh.1. A–G. Polychaetaspis kozlowskii sp. nov. A. ZPAL Sc.8/2.6, holotype, right MI in dorsal view. B. ZPAL Sc.8/2.15, right MI in dorsal view. C. ZPAL Sc.8/2.14, incomplete right MI in dorsal (C 1) and ventral (C 2) views. D. ZPAL Sc.8/2.5, basal plate in dorsal (D 1) and right lateral (D 2) views. E. ZPAL Sc8/2.17, left MI in dorsal (E 1) and left lateral (E 2) views. F. ZPAL Sc.8/2.13, left MI in dorsal (F 1) and oblique ventral (F 2) views. G. ZPAL Sc.8/2.4, left MI in dorsal (G 1) and oblique left lateral (G 2) views. H. Polychaetaspis? sp., ZPAL Sc.8/2.20, left MIII? in dorsal (H 1) and right lateral (H 2) views. I–L. Polychaetaspis? spp. anterior plates (MIV). I. ZPAL Sc8/2.1, right MIV in dorsal (I 1) and dorsal lateral (I 2) views. J, K. Right MIV in ventral lateral view. J. ZPAL Sc8/2.12. K. ZPAL Sc.8/2.11. L. ZPAL Sc8/2.24, left MIV in ventral lateral view.