Belemnella (Neobelemnella) kazimiroviensis ( Skołozdrówna, 1932 )

Keutgen, Norbert, Remin, Zbigniew & Jagt, John W. M., 2017, The late Maastrichtian Belemnella kazimiroviensis group (Cephalopoda, Coleoidea) in the Middle Vistula valley (Poland) and the Maastricht area (the Netherlands, Belgium) - taxonomy and palaeobiological implications, Palaeontologia Electronica 6 (3), pp. 1-29 : 17-21

publication ID	https://doi.org/ 10.26879/671
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scientific name	Belemnella (Neobelemnella) kazimiroviensis ( Skołozdrówna, 1932 )
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Treatment

Belemnella (Neobelemnella) kazimiroviensis ( Skołozdrówna, 1932)

Figure 17 View FIGURE 17

1932 Belemnitella kazimiroviensis Skołozdrówna , p. 117.

1951 Belemnella casimirovensis (Skolozdrówna) var. skolozdrównae ; Jeletzky (pars), p. 119, pl. 6, figure 4, pl. 7, figure 4 (non pl. 7, figure 1).

1951 Belemnella casimirovensis (Skolozdrówna) var. archangelskyi ; Jeletzky (pars), p. 119, pl. 6, figure 3.

1957 Belemnella casimirovensis archangelskyi Jeletzky, 1951 ; Birkelund, p. 52, pl. 6, figure 5ac.

1962 Belemnitella pensaensis Naidin, 1952 ; Kongiel, p. 32, pl. 1, figures 4-12, pl. 2, figures 1-6, pl. 3, figures 1-3.

1962 Belemnitella archangelskyi ( Jeletzky, 1951) ; Kongiel, p. 33, pl. 2, figures 7-12, pl. 3, figures 4-6, 10-12, pl. 4, figures 1-3.

1962 Belemnitella kazimiroviensis Skołozdrówna, 1932 ; Kongiel (pars), p. 35, pl. 3, figures 7-9, pl. 4, figures 4-12, pl. 5, figures 1-3, 7-12, pl. 6, figures 1-6 (non pl. 5, figures 4-6).

1962 Belemnitella skolozdrównae ( Jeletzky, 1951) ; Kongiel (pars), p. 36, pl. 6, figures 10-12, pl. 7, figures 1-9 (non pl. 6, figures 7-9).

2012b Belemnella (Neobelemnella) gr. kazimiroviensis ( Skołozdrówna, 1932) ; Jagt, p. 100, pl. 2, figures 4-6.

2012c Belemnella (Neobelemnella) ex gr. kazimiroviensis ( Skołozdrówna, 1932) ; Jagt, p. 131, pl. 28, figures B-C, I, L.

Material. Three fragments (Mcd45/1, Mcd45/2,

and Mcd52) from the white opoka exposed at

Mięćmierz) and one specimen (Mcd37) from Kazimierz, from level "w" of Pożaryski (1938). 18 specimens from the level "x" of Pożaryski, from the

Kazimierz Opoka including two from Kazimierz

(Mcd36, Mcd44/5), six from Bochotnica (Mcd35/1,

Mcd43/1, Mcd43/3, Mcd43/4, Mcd43/6, and

Mcd51/4) and eight from Nasiłów (Mcd42/1–42/5,

Mcd50/9–50/12). Level "y" of Pożaryski (1938)

yielded two specimens, one (Mcd41) from Bochotnica and another (Mcd48) from Nasiłów. New collection from the glauconitic sandstone, above the

Kazimierz Opoka at Nasiłów (= level "z" of

Pożaryski (1938) yielded as follows: 20 specimens from the glauconitic sandstone below the "phosphatic layer" ( MWGUW ZI/69/02, 04-08, 31, 35, 66, 68, 71-73, 75-78, 80, 85, 87); 25 specimens and from the "phosphatic layer" ( MWGUW ZI/69/13-14, 16-17, 20-21, 42-56, 58-59, 62, 64). The lower part of greenish sandy gaize at the base of the Siwak yielded eight specimens ( MWGUW ZI/69/26, 37- 38, 40-41, 88-90).

The stratigraphically oldest specimens studied from the Netherlands ( NHMM JJ 8338 – JJ 8339 ) are from subunit IVf-4 of the Meerssen Member at the former Blom quarry, followed by a specimen from either subunit IVf-4 or -5 from the ENCI-HeidelbergCement Group quarry ( NHMM JJ 8758 ) . Specimen NHMM JJ 2440 stems from either subunit IVf-5 or -6 as formerly exposed at the Albert Canal near Vroenhoven. Three specimens are known from subunit IVf-6: from the former Blom quarry (base IVf-6; NHMM 2015 View Materials NK001-11), from the uppermost Meerssen Member as exposed at the ENCI-Heidelberg Cement Group quarry (probably IVf-6; NHMM MK4594 ) and from the former Curfs quarry (top IVf-6 - 0.5 m; NHMM JJ 7175 ) . From immediately above the Berg en Terblijt Horizon (K– Pg boundary) 14 specimens have been studied from the Geulhemmergroeve subterranean galleries near Geulhem ( NHMM MK 2505–2508 , MK 2514–2519 , MK 2522 , NHMM 2015 View Materials NK001-2, NHMM 2015 View Materials NK001-3, and NHMM 2015 View Materials NK001- 4), in addition to one specimen from the former Blom quarry ( NHMM MK 2723 ) . The lowermost 0.05 m above the Vroenhoven Horizon (lowermost Geulhem Member, Houthem Formation) have yielded 12 specimens ( NHMM 2015 View Materials NK001-13, NHMM 2015 View Materials NK001-14, NHMM 2015 View Materials NK001-15, NHMM 2015 View Materials NK001-17, NHMM 2015 View Materials NK001-20, NHMM 2015 View Materials NK001-21, NHMM 2015 View Materials NK001-22, NHMM 2015 View Materials NK001-23, NHMM 2015 View Materials NK001-26, NHMM 2015 View Materials NK001-28, NHMM 2015 View Materials NK001-32, and NHMM 2015 View Materials NK001-37) at the Albert Canal near Vroenhoven and three specimens ( NHMM JJ 14048-1 , JJ 14048-6 , JJ 14048-7 ) in the former Curfs-Ankerpoort quarry .

Description. Guard shape in Bln. kazimiroviensis varies from subcylindrical to slightly lanceolate in ventral view. In lateral view, guards are subconical to subcylindrical. Guard length (Ls) usually is small to large, but extraordinarily large guards may rarely occur, indicating that the populations from the Middle Vistula valley and Maastricht area consists mainly of specimens that have not reached their physiologically possible maximum size. The standardised length (Lsn) varies from c. 42 to 64 mm. Schatzky distances are relatively small (1.0– 4.7 mm) with population mean values around 3.4 mm. The alveolar angle ranges from 16° to 21°. The fissure angle is highly variable and ranges from 24° to 138° (mean value c. 73°). In well-preserved guards the vascular markings and double furrows are well developed. Longitudinal striae crossing the vascular markings result in a kind of pseudogranulation that is most distinct in the anterior part of the guard. The apical end may be acute to roundedacute; only in larger specimens is it more rounded. A distinct mucro is rarely visible. The ontogenetic growth quotient of individual guards (WQs) was calculated on four specimens (MWGUW ZI/69/07, 16, 59, and NHMM 2015 NK001-14); the mean value being 3.73.

The relationship BI vs Dp ( Figure 18 View FIGURE 18 ) of guards of Bln. kazimiroviensis is not linear as in the genus Belemnitella d’Orbigny, 1840 . Instead, small (young) individuals are distinctly more slender than larger (adult) ones. This allometric growth is, in addition to other aspects, considered typical of the genus Belemnella .

From the regression equation ( Figure 18 View FIGURE 18 ), BI x-values for Dp 1 = 5 mm and Dp2 = 16 mm were calculated. The corresponding BI1- and BI2-values were used to calculate Ls1 and Ls2, from which the "alternative WQs" could be deduced. In this way, based on a large population, the calculated "alternative WQs" accounts for 3.33 and is distinctly smaller than the mean value of the ontogenetic growth quotient of individual guards (WQs = 3.73) calculated from merely four specimens. The Lsn values of Bln. kazimiroviensis are best calculated as follows:

Lsn = Dpn x BIn = 9.9 x (5.28 + (BI – (-1.932ln(Dp) + 9.7097)))

(in mm)

Although the majority of specimens of Bln. kazimiroviensis from the Maastricht area plot well within the range of this species from the Middle Vistula valley region, the mean values of AV and AL indicate that the Maastricht specimens are slightly more subcylindrical in ventral and more subconical in lateral view ( Table 4). The significance of this observation is not yet clear. It might indicate a developmental trend, since the population from the Maastricht area represents the stratigraphically youngest population studied, but it may also simply reflect a local phenomenon of the Maastricht population that established itself on the western margin of distribution of Bln. kazimiroviensis .

Discussion. Belemnella kazimiroviensis represents the type species of the kazimiroviensis group. However, many varieties of this species have been distinguished. Jeletzky (1951) was the first who formally introduced Bln. kazimiroviensis , making reference to " Belemnitella kazimiroviensis " of Skołozdrówna (1932). Unfortunately, he misspelt the name as "casimirovensis ". Jeletzky examined the Skołozdrówna Collection at L’viv ( Ukraine), and received a few specimens from this lot. From these he selected one as the holotype of Bln. kazimiroviensis . Presumably Jeletzky had already recognised the presence of two species of Belemnella in the uppermost Maastrichtian of the Middle Vistula valley in Poland, which allowed him to differentiate between two varieties, " Belemnella casimirovensis (Skolozdrówna) var. skolozdrównae " and " Belemnella casimirovensis (Skolozdrówna) var. archangelskyi ". He intended to have the name of the first species to refer to the more slender, lanceolate variety characterised by larger fissure angles, which is generally rare, but seemingly more common in the central Vistula valley than elsewhere. The present results seem to imply that what Jeletzky (1951) had in mind is what is here referred to as Bln. skolozdrownae ( Kongiel, 1962) . However, the present study also revealed that the fissure angle of Jeletzky’s holotype of " Belemnella casimirovensis (Skolozdrówna) var. skolozdrównae " is relatively small, characterising it as a slender representative of the "var. archangelskyi " sensu Jeletzky (1951).

Jeletzky (1951) clearly stated that the holotype of the variety " Belemnella casimirovensis (Skolozdrówna) var. skolozdrównae " was also the holotype of " Belemnella casimirovensis (Skolozdrówna) ". As a consequence, the variety skolozdrównae of Jeletzky (1951) is invalid. Instead, the holotype of Jeletzky should be referred to as Bln. kazimiroviensis kazimiroviensis if a subspecies would need to be distinguished, as proposed earlier by Birkelund (1957).

With respect to the "var. archangelskyi " of Jeletzky (1951), it may be concluded that, following his concept, this variety must be regarded as a synonym of Bln. kazimiroviensis kazimiroviensis , because the holotype of the latter species is not a member of the second, more slender and more lanceolate form (i.e., Bln. skolozdrownae ) that occurs in the Middle Vistula valley. However, since the holotype of " Belemnella casimirovensis (Skolozdrówna) var. archangelskyi " is a specimen from the Turgay Plateau (northwest Kazakhstan), as illustrated by Arkhangelsky (1912) under the designation " Belemnitella americana ", it cannot be ruled out that this represents indeed a valid geographical (sub)species of Bln. gr. kazimiroviensis . This shall be the subject of future studies.

Naidin (1952) listed two varieties of " Belemnitella arkhangelskii nomen novum", namely " Belemnitella arkhangelskii nomen novum var. pontica (Rousseau) " and " Belemnitella arkhangelskii nomen novum var. pensaensis var. nov. " While, for the time being, the holotype of Belemnites ponticus is best regarded as a nomen dubium ( Kongiel, 1962), that of Bln. pensaensis deserves further discussion. According to the original description ( Naidin, 1952), the holotype of Bln. pensaensis from Nikiforowka near Penza (central Russia) was comparatively stout and characterised by a relatively small fissure angle. Jeletzky (1958) accepted the validity of the Bln. pensaensis and argued that representatives of the kazimiroviensis group from central Russia might differ slightly from those recorded from southern Russia and Central Asia (i.e., the origin of the holotype of Bln. arkhangelskii ) as well as from those of Poland (i.e., origin of the holotype of Bln. kazimiroviensis ), implying that Bln. arkhangelskii and/or Bln. pensaensis might represent valid geographical (sub)species of the kazimiroviensis group.

Kongiel (1962) erected an additional species of the kazimiroviensis group, viz. Bln. skolozdrownae . He argued that the holotype of " Belemnella casimirovensis (Skolozdrówna) var. skolozdrównae ", as selected by Jeletzky (1951), with respect to its fissure angle, did not reflect the course of the ventral fissure as described by Skołozdrówna for " Belemnitella kazimiroviensis ". Consequently, he selected another holotype for Bln. skolozdrownae from one of the paratypes of Jeletzky (1951, pl. 7, figure 1) – the specimen from Stevns Klint ( Denmark). Because the designation "var. skolozdrównae " was incorrectly introduced by Jeletzky (1951), the holotype introduced by Kongiel is considered valid. The holotype of Bln. skolozdrownae sensu Kongiel (1962) differs from Bln. kazimiroviensis in its more slender guard, more lanceolate shape, and larger fissure angle. In addition, it reflects well the concept of " Belemnella casimirovensis (Skolozdrówna) var. skolozdrównae " of Jeletzky (1951) and is here accepted as the holotype of the second species that is rare in central and western Europe.

Distribution. With respect to the locus typicus and stratum typicum of Bln. kazimiroviensis Jeletzky (1951, p. 122) mentioned "… Locus typicus: Umgebung der Stadt Kazimierz an der Weichsel in Polen. Stratum typicum: Oberste Horizonte der Maastricht-Stufe (Horizonte "w", "x", "y" (nicht "z"!) von Pożaryski (1938, S. 18-19)…" This actually restricts the origin of the holotype of Bln. kazimiroviensis to the Kazimierz Opoka and excludes the glauconitic sandstone at its top, although it may be questioned whether the holotype did indeed come from the opoka, since Jeletzky did not collect it by himself. In view of the fact that Jeletzky refused the glauconitic sandstone as a stratum typicum, we are left here essentially with the upper part of the upper Maastrichtian Kazimierz Opoka as exposed at Nasiłów, Bochotnica, and at the Town Quarry at Kazimierz Dolny (the latter with numerous belemnites only in the marls at the top of the exposure) as a potential stratum typicum for Bln. kazimiroviensis . All these levels correspond to the late but not latest Maastrichtian H. constrictus crassus Zone.

Belemnella kazimiroviensis occurs in the upper upper Maastrichtian of the Middle Vistula valley in Poland, at several localities in Denmark and in the uppermost Maastrichtian of the Maastricht area ( the Netherlands, Belgium). The late Maastrichtian specimens of Bln. kazimiroviensis illustrated by Naidin (1975) from central and southern Russia and Central Asia are characterised by mean values for characteristic parameters that do not differ from those of the populations from the Middle Vistula valley ( Table 4) and may, thus, also be referred to as Bln. kazimiroviensis , unless future studies will prove the existence of geographical (sub)species in these areas.