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Revision of Hamites wernickei Wollemann, 1902 (Cephalopoda, Ancyloceratina) from the classic Lüneburg section (Upper Cretaceous, northern Germany)

Revision of Hamites wernickei Wollemann, 1902 (Cephalopoda, Ancyloceratina) from the classic... Niebuhr, B. and Jagt, J.W.M. 2016. Revision of Hamites wernickei Wollemann, 1902 (Cephalopoda, Ancyloceratina) from the classic Lüneburg section (Upper Cretaceous, northern Germany). Acta Geologica Polonica, 66 (4), 627­644. Warszawa. A re-examination of heteromorph ammonites of late Campanian age from the Zeltberg section at Lüneburg has demonstrated that the type series of Hamites wernickei in fact comprises two different species that are here assigned to the nostoceratid Nostoceras Hyatt, 1894 and the polyptychoceratid Oxybeloceras Hyatt, 1900. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) comb. nov., to which three of the four specimens that were described and illustrated by Wollemann (1902) belong, has irregularities of ribbing and tuberculation and changes its direction of growth at the transition from the helicoidal whorls to the hook, which is a typical feature of members of the subfamily Nostoceratinae. Torsion of body chambers is not developed in hairpin-shaped ammonite species, which means that the species name wernickei is no longer available for such polyptychoceratine diplomoceratids. Consequently, the fourth specimen figured and assigned to Hamites wernickei by Wollemann (1902) is here transferred to Oxybeloceras and considered conspecific to material from the Hannover area (Lehrte West Syncline) as O. aff. crassum (Whitfield, 1877). In addition to the "Heteroceras-Schicht des Mucronaten-Senons" of Lüneburg (bipunctatum/roemeri Zone, upper upper Campanian), the geographic range of N. (D.) wernickei probably includes Upper Austria, Tunisia and the Donbass region, while O. aff. crassum is known from the Hannover area (northern Germany), southern France, northern Spain and Upper Austria. Key words: Campanian; Ammonites; Nostoceras; Oxybeloceras; Taxonomy; Europe. INTRODUCTION Wollemann (1902) described and illustrated a suite of ammonite species that he had collected at the Zeltberg Quarry of Lüneburg (Niedersachsen, c. 30 km southsouth-east of Hamburg, northern Germany) at the end of the nineteenth century. Notable are bituberculate heteromorphs which he assigned to a new species, Hamites wernickei (see Wollemann 1902, p. 95). Wollemann noted that, "The sculpture is so simple and characteristic that, on the basis of this, the species is easily recognised and differentiated from Hamites species already known" ["Die Sculptur ist so einfach und charakteristisch, dass die Art leicht an dieser erkannt und von den bereits bekannten Hamites-Arten unterschieden werden kann"]. The type series of Wollemann's new species falls into two size categories: I. three large-sized specimens represent well-separated, U-shaped curved portions of bituberculate hetero- morphs (i.e., Wollemann 1902, pl. 4, fig. 4; pl. 5, figs 1, 2), and II. a single small, hairpin-like specimen develops approximated parallel shafts, originally interpreted as the inner portions of a polyptychoceratid ["innere Windung" sensu Wollemann 1902, p. 95, pl. 4, fig. 5]. Subsequent records of heteromorph ammonites under the name of wernickei were either not figured (e.g., Diener 1925; Poaryski 1948; Wiedmann 1964; Klinger 1982; Kaplan et al. 2005), showed unequivocally different species of the subfamily Polyptychoceratinae [e.g., Mikhailov 1951; Wiedmann 1962; Klinger 1976; Tzankov 1982; Kennedy and Summesberger 1984 (in part); Lommerzheim 1995; Kaplan et al. 1996; Küchler 2000] or were species of indeterminate familial assignment [Pervinquière 1907; Naidin in Krymgolts 1974; Kennedy and Summesberger 1984 (in part)]. In most cases, what authors understood to represent the species named wernickei were the three large U-shaped curved individuals from the type series (Wollemann 1902, pl. 4, fig. 4; pl. 5, figs 1, 2) (see e.g., Pervinquière 1907; Mikhailov 1951; Wiedmann 1962; Naidin in Krymgolts 1974; Klinger 1976; Tzankov 1982). Küchler (2000) even included the small hairpin-like specimen (Wollemann 1902, pl. 4, fig. 5) in it. Kennedy and Summesberger (1984, p. 167) adopted the species name wernickei for both size categories, I (i.e., larger specimens of Kennedy and Summesberger 1984, pl. 10, figs 1, 9) and II (i.e., small specimens of Kennedy and Summesberger 1984, pl. 9, figs 6, 7), listing it as Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902). However, they did not include the small specimen figured by Wollemann (1902, pl. 4, fig. 5) in their size category II, yet discussed the possibility that it, "may be better referred to `Hamites' interruptus Schlüter, 1872". In our opinion, the four specimens illustrated under the name wernickei by Wollemann (1902) in fact belong to two different families, genera and species, as follows. Species I. Of the three large heteromorphs illustrated in his pl. 4, fig. 4 and pl. 5, figs 1 and 2, Wollemann (1902) noted that, "A few compressed and twisted whorls of the tuberculate Heteroceras polyplocum are at times quite similar to our hamitid" ["Einzelne zusammengedrückte und verdrehte Windungen der mit Knoten versehenen Form des Heteroceras polyplocum sind unserem Hamiten bisweilen sehr ähnlich"]. All three distinctly Ushaped specimens of Wollemann (1902) develop a change in direction of growth ["deutliche Torsion der Wohnkammer", sensu Wiedmann 1962, p. 209] and irregularities of ribbing and tuberculation which are missing in polyptychoceratines, yet are characteristic of the Nostoceratinae. Although Wollemann (1902, p. 96) noted that the large-sized heteromorphs, named wernickei, ap- peared to be relatively common together with his Heteroceras polyplocum ["zh. = ziemlich häufig, MH. = Heteroceras-Schicht des Mucronaten-Senons"], additional, similarly shaped "Hamites" specimens have never been recovered subsequently, not in large suites of Polyptychoceratinae from the Lehrte West Syncline near Hannover (Niebuhr et al. 1997; Niebuhr 2004; Jagt 2013), nor in the "Haldemer Schichten" at the Stemweder Berg (Kennedy and Kaplan 1997), the Münsterland Cretaceous Basin (Lommerzheim 1995; Kaplan et al. 2005), Tercis les Bains, southwest France (Odin et al. 2001) and the Vistula River Valley, Poland (Blaszkiewicz 1980). Kaplan et al. (2005, pp. 30, 43) recorded Pseudoxybeloceras (Parasolenoceras) wernickei from older strata in the southeastern part of the Münsterland Cretaceous Basin (i.e., Beckum Member, Coesfeld Formation; lowermost upper Campanian), but failed to illustrate the single specimen available to them. Poaryski (1948) had earlier noted "Hamites wernickei Woll." from the Polish Didymoceras donezianum Zone (equivalent to the north German bipuctatum/roemeri Zone; upper upper Campanian), but did not provide an illustration either. However, these records were not confimed by Blaszkiewicz (1980). Wiedmann (1962, p. 209) designated as lectotype of wernickei the original of Wollemann (1902, pl. 5, fig. 1). Later, Kennedy and Summesberger (1984, p. 166), apparently unaware of Wiedmann's prior designation, selected the original of Wollemann's pl. 4, fig. 1 as lectotype (actually a gastropod; it should have stated pl. 4, fig. 4); this is an error. It seems clear that all three authors understood the species name wernickei to be applicable to large-sized, U-shaped heteromorphs (Wollemann 1902, pl. 4, fig. 4; pl. 5, figs 1, 2). Unfortunately, the Wollemann Collection which was housed at the museum and the "Altes Kaufhaus" of Lüneburg was destroyed in a fire in December 1959 (i.e., predating Wiedmann's lectotype designation). In other words, Wiedmann's lectotype is lost. However, in the collection of the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, two U-shaped body chambers and c. 20 fragments of the coiled portion of wernickei from the Zeltberg Quarry in Lüneburg are kept, collected in 1956 and 1980 by Friedrich Schmid. Furthermore, in the BGR BerlinSpandau collection, the collection of the Senckenberg Naturhistorische Sammlungen Dresden and in the collection of D. Schumacher (Lüneburg), are six, one and seven fragments of the coiled portion with up to four whorls in contact, respectively. These specimens are here described and illustrated for the first time. Species II. The original of the small, hairpin-like specimen of Wollemann (1902, pl. 4, fig. 5) is housed in the BGR Berlin-Spandau collection. It clearly is a member of the subfamily Polyptychoceratinae. Conspecific material is known from the upper Campanian of the Hannnover area (northern Germany), as described and illustrated by Jagt and Neumann (2006), in open nomenclature [Oxybeloceras aff. crassum (Whitfield, 1877); see also Jagt 2013]. The size of the teardrop-shaped opening is similar to that in material from the upper Campanian of Montana, Wyoming and Colorado, and rib density overlaps. Jagt and Neumann (2006) remarked that the limited material from the Lehrte West Syncline near Hannover (MAB 3290a­b; C. Holschemacher Collection, Berlin) appeared to have less closely spaced ribbing on the smaller limb and a less regular occurrence of ventrolateral tubercles. For now, we prefer to keep this form in open nomenclature until better-preserved material becomes available. the collections from the "Heteroceras-Schicht des Mucronaten-Senons" at Lüneburg. REPOSITORIES OF MATERIAL BGR MA: Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover, Germany. BGR X: Bundesanstalt für Geowissenschaften und Rohstoffe, Berlin-Spandau, Germany. MAB: Oertijdmuseum De Groene Poort, Boxtel, the Netherlands. MMG: Senckenberg Naturhistorische Sammlungen Dresden, Museum für Mineralogie und Geologie, Sektion Paläozoologie, Dresden, Germany. MN: Museum für Naturkunde, Berlin, Germany. NHMM: Natuurhistorisch Museum Maastricht, Maastricht, the Netherlands. SH: Detlef Schumacher Collection, Lüneburg, Germany. ASSOCIATED AMMONITE FAUNA AND BIOSTRATIGRAPHY In addition to N. (D.) wernickei and O. aff. crassum, as here interpreted, Wollemann (1902) mentioned from the "Heteroceras-Schicht des Mucronaten-Senons" (as recently identified by one of us, BN): Menuites wittekindi (Schlüter, 1872), Menuites portlocki portlocki (Sharpe, 1855), Hoploscaphites greenlandicus (Donovan, 1953) and Gaudryceras mite (von Hauer, 1866). "Heteroceras polyplocum A. Roemer sp." of Wollemann (1902) does not belong to Nostoceras (Bostrychoceras) polyplocum (Roemer, 1841), but rather refers to the helicoidal portions of N. (D.) wernickei (see below). Furthermore, Pseudoxybeloceras (Parasolenoceras) interruptum (Schlüter, 1872), Lewyites elegans (Moberg, 1885) and Hoploscaphites compressus (Roemer, 1841) have recently been identified from upper Campanian strata exposed at the Zeltberg Quarry (Niebuhr, in prep.). Large-sized species of Nostoceras (Didymoceras), in association with M. wittekindi, M. p. portlocki, Ps. (Pa.) interruptum, H. greenlandicus and H. compressus, are typical of the bipunctatum/roemeri Zone (upper upper Campanian) of the Lehrte West Syncline near Hannover (Niedersachsen, northern Germany, c. 100 km south of Lüneburg). Lewyites elegans first appears in the lower upper Campanian and ranges into the bipunctatum/roemeri Zone (Niebuhr 1996, 2004; Niebuhr et al. 1997, p. 223; Küchler and Schneider 2013). Gaudryceras mite is a long-ranging taxon, with records from Turonian to Maastrichtian strata (Kennedy and Summesberger 1979; Summesberger and Kennedy 1996). Only the upper upper Campanian is indicated in SYSTEMATIC PALAEONTOLOGY Abbreviations used are as follows: D ­ diameter; vL ­ ventral length of nostoceratids, measured between lower and upper rows of tuberculation; Ah ­ apertural height; Wh ­ whorl height; Wb ­ whorl breadth; Ri ­ rib index, number of ribs in a distance equal to the whorl height; Rr ­ rib ratio, ventral length divided by rib number. Order Ammonoidea von Zittel, 1884 Suborder Ancyloceratina Wiedmann, 1966 Superfamily Turrilitoidea Gill, 1871 Family Nostoceratidae Hyatt, 1894 Subfamily Nostoceratinae Hyatt, 1894 Genus Nostoceras Hyatt, 1894 TYPE SPECIES: Nostoceras stantoni Hyatt, 1894 = Ancyloceras? approximans Conrad, 1855, by original designation of Hyatt (1894, p. 569). REMARKS: The classification of Wright et al. (1996, p. L245) is followed here. Subgenus Didymoceras Hyatt, 1894 TYPE SPECIES: Ancyloceras? nebrascensis Meek and Hayden, 1856, by original designation of Hyatt (1894, p. 574). DIAGNOSIS: Early growth stage of either loose and ir- regular helical coils or straight limbs connected by elbows, even hamitoid; followed by a middle growth stage of helical whorls just touching or not so; body chamber in a retroversal whorl, U- or C-shaped. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) comb. nov. (Text-figs 1­3, 5­7) pars * 1902. Hamites Wernickei Wollemann, p. 95, pl. 4, fig. 4; pl. 5, figs 1­2 [non pl. 4, fig. 5 = Oxybeloceras aff. crassum (Whitfield, 1877)]. ? 1907. Hamites (Anisoceras?) Wernickei Wollemann; Pervinquière, p. 86, pl. 3, fig. 33. non 1951. Anisoceras wernickei Wollemann; Mikhailov, p. 40, text-fig. 9, pl. 1, fig. 1 (= Polyptychoceratinae sp. indet.). non 1962. Neancyloceras wernickei (Wollemann); Wied- mann, p. 209, pl. 12, fig. 5 (= Polyptychoceratinae sp. indet.). ? 1974. Neancyloceras wernickei (Wollemann, 1902); Naidin in Krymgolts, p. 169, pl. 57, fig. 4. non 1976. Neancyloceras sp. cf. Neancyloceras wernickei (Wollemann), 1902; Klinger, p. 73, pl. 33, fig. 4; text-figs 8i, 10f (= Polyptychoceratinae sp. indet.). ? 1984. Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902); Kennedy and Summesberger, p. 166, pl. 10, fig. 1 only. non 1984. Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902); Kennedy and Summesberger, p. 166, pl. 6, fig. 3 [= Lewyites elegans (Moberg, 1885)]; pl. 9, figs 6­7 [= Oxybeloceras aff. crassum (Whitfield, 1877)]; pl. 10, figs 8­9 (= Polyptychoceratinae sp. indet.). non 1995. Pseudoxybeloceras (Parasolenoceras)(?) cf. wernickei (Wollemann, 1902); Lommerzheim, Text-fig. 2. Nostoceras (Didymoceras) wernickei (Wollemann, 1902); reillustration of Hamites wernickei of Wollemann (1902, pl. 5, fig. 1); U-shaped body chamber with adult aperture, transitional part with torsion and bifurcation of ribs. Natural size Text-fig. 1. Nostoceras (Didymoceras) wernickei (Wollemann, 1902). A­B ­ Reillustration of Hamites wernickei of Wollemann (1902, pl. 5, fig. 2); adult bituberculate specimen with complete U-shaped body chamber and younger portions of the last whorl; note torsion of transitional part and break between body chamber and helicoidal part, and ventral view of the same, respectively, showing details of the transitional part with rib bifurcation. C ­ Reillustration of Hamites wernickei of Wollemann (1902, pl. 4, fig. 4); U-shaped body chamber and transitional part with torsion and bifurcation of ribs. All specimens are natural size p. 68, pl. 7, figs 5­6a-c (= Polyptychoceratinae sp. indet.). non 1996. Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902); Kaplan et al., p. 41, pl. 35, figs 6­7 (= Polyptychoceratinae sp. indet.). non 2000. Pseudoxybeloceras (Parasolenoceras) ?wernickei (Wollemann); Küchler, pl. 12, figs 1­3 [= Oxybeloceras aff. Crassum (Whitfield, 1877)]. DIMENSIONS: Collection number pl. 4, fig. 4 pl. 5, fig. 1 pl. 5, fig. 2 Growth stage late late late, middle BGR MA 14514 BGR MA 14515 BGR MA 14520 BGR MA 14518 BGR MA 14516 BGR MA 14517 BGR MA 14519 SH 42 late late mid., W1 mid., W1 mid., W1 mid., W1 mid., W1 middle, W1­W4 Tubercles, swellings, constrictions bituberculate bituberculate bituberculate ?nontuberculate bituberculate bituberculate nontuberculate nontuberculate nontuberculate nontuberculate nontuberculate W4: nontub. W3: ?lower row W2: nontub. W1: nontub. BGR X 13000 middle, W1­W3 nontuberculate, 5 constrictions > 270 mm > 280 mm vL of body chamber > 215 mm > 280 mm 285 mm TYPES: Lectotype, designated by Wiedmann (1962, p. 209), was the original of Wollemann (1902, pl. 5, fig. 1; reillustrated here as Text-fig. 2) which had been lost in December 1959. To replace this we here designate a neotype, BGR MA 14514. Locus typicus is the Zeltberg Quarry at Lüneburg, Niedersachsen, northern Germany. Stratum typicum is the "Heteroceras-Schicht des Mucronaten-Senons" of Wollemann (1902), which is the equivalent of the bipunctatum/roemeri Zone (upper upper Campanian), c.1.5 myr below the CampanWh of body chamber 36 mm 43­45 mm 38­44 mm 34 mm 32­38 mm 32­41 mm 54 mm 53 mm 50 mm 49 mm 48 mm W4: 31 mm W3: 38 mm W2: 46 mm W1: 46 mm W3: 24 mm W2: 33 mm W1: 42 mm 0.8 0.6 0.5 0.5 0.5 0.6 4.0 2.5 2.8 3.8 3.4 3.4 11.5 13 14 13 11 12 0.9 Wh of helicoidal whorl Wb/Wh Rr (vL/ribs) 7.7 8.5 8.3 3.0 9.3 9.5 2.8 4.5 4 3.3 3.4 2.6 3.1 12 12.5 Ri (ribs equal Wh) 5­7 7­9 7.5 11 5.5 5.5 19 15 13 14 BGR X 13001 middle, W1­W2 nontuberculate W2: 37 mm W1: 41 mm MMG NsK 3 early, W4 middle, W1­W3 W4: ? W1­W3: bituberculate, W3: constriction few swellings older: nontub., younger: bitub. W4: >14 mm W3: 22 mm W2: 33 mm W1: 40 mm 26­40 mm 33­39 mm 0.9­1 2.6 2.5 3.3 2.3­3.3 3.0 9 11 12 12 12.5 SH 49 SH 48 middle mid., W1 BGR X 13002 BGR MA 14523 BGR MA 14521 SH 41 SH 31 mid., W3 early early early early nontuberculate bituberculate bituberculate nontuberculate bituberculate 22­28 mm 18­22 mm 16 mm 15 mm 9­10 mm 0.7­0.6 0.7­0.8 0.8 1.1 0.8­1 2.2 1.8 1.4 3.5 1.2­1.8 11 13 13 7 9­10 Table 1. Dimensions of Nostoceras (Didymoceras) wernickei (Wollemann, 1902). Grey: Wollemann's (1902) specimens; bold: BGR MA 14514, designated neotype ian/Maastrichtian boundary (compare Niebuhr et al. 2011). MATERIAL: In addition to the neotype (BGR MA 14514, see above), one U-shaped body chamber (BGR MA 14515) and approximately 25 fragments of helicoidal whorls (e.g., BGR MA 14516­14523; BGR X 13000­13006; MMG NsK 3; and SH 31, SH 41­42, SH 48­49). DESCRIPTION: Nostoceras (D.) wernickei is both sinistrally (Text-figs 1A­B, 2, 3B­C) and dextrally coiled (Text-fig. 1C). Phragmocone and body chamber whorls have Wb/Wh ratios of 0.5­1. Adult body chambers are distinctly U-shaped, enlarged towards the aperture and may become pipe-like; weak collared constrictions can appear. Rib indices of body chambers are 5­9, while in helicoidal whorls they may reach 11­19 (with a mean value of 13). Rib ratios show the same differentiation: phragmocones of the middle growth stage are more finely ribbed with ratios smaller than 4.5, while more coarsely ribbed body chambers have ratios of 7.5­9.5 (Table 1). The change in ribbing density appears abruptly (see Text-fig. 1A). The three body chambers illustrated by Wollemann (1902, reillustrated here in Text-figs 1­2) and the two completely preserved body chambers housed in the BGR Hannover collection (Text-fig. 3) are quite similar with two c. 60 mm-long, near-parallel shafts separated by a 20­30 mm wide opening between them. The curved sector connecting the shafts is subcircular. This habitus of body chambers has led previous authors to refer this species to the Polyptychoceratinae. The three specimens of Wollemann (1902) (see Text-figs 1­ 2) and one of the BGR Hannover individuals (Text-fig. 3B) show the torsion of the transitional part. The body chambers and transitional parts bear coarse, distant, sharp bituberculate ribs that are mostly annular or bifurcate, and may zigzag a few times between separated tubercles. Wollemann (1902, p. 95) also observed this in his Hamites wernickei when he wrote, "Die meisten Rippen verlaufen von dem Knoten der Externkante ungetheilt über die Externseite zum Knoten der anderen Externseite; in einzelnen Fällen findet eine Gabelung in der Weise statt, dass ein Knoten der einen Externkante je eine Rippe zu zwei neben einander stehenden Knoten der anderen Externkante entsendet". Tuberculation is regular, coarsens towards the curved sector of the body chamber and, in most cases, effaces during the transition to the coiled middle growth stage (Text-fig. 1A, C). Apart from one of Wollemann`s specimens (1902, pl. 5, fig. 2a; reillustrated here as Text-fig. 1A) there are no specimens which show the transition from the helically coiled middle growth stage to the merely loosely connected body chamber. At this particular point, most fragments are broken as a result of differential preservation (see Text-figs 1, 3), also observed by Wollemann (1902, figure caption of pl. 5, fig. 2a). All fragments of W1­W4 (i.e., the last four whorls) with Wh 22­54 mm have simple, mostly nontuberculate primaries (Table 1). Specimen BGR X 13000 bears 1­2 collared constrictions per whorl between Wh 33­42 mm. Whorls of the early growth stage are helicoidal up to a minimum Wh 16 mm, are mostly bituberculate, but, in a few cases, can also be nontuberculate (Text-figs 5D, 6B). Low Wb/Wh ratios of the middle growth stage, developed in specimen SH 42 (Text-fig. 7), seem to be of primary nature and not the result of compaction. DISCUSSION: Nostoceras (Didymoceras) wernickei ranks among the larger European nostoceratid ammonites with U-shaped body chambers attaining up to 285 mm, and is comparable in this respect to Nostoceras (Didymoceras) postremum (Blaszkiewicz, 1980) from the Lehrte West Syncline, c. 100 km south of Lüneburg, which has a loosely connected C-shaped body chamber up to 300 mm (Niebuhr 2004; see Text-fig. 4A­B here). Both N. (D.) wernickei from Lüneburg and N. (D.) postremum from the Lehrte West Syncline are defined by their distinct body chambers. In N. (D.) wernickei coiling in the middle growth stage is helicoidal with whorls not touching or barely so, and the early growth stage is regular openly coiled. However, helicoidal whorls of the middle growth stage between Wh 22­54 mm are not diagnostic and show considerable similarities, both in dimensions and ornament, to mostly nontuberculate Nostoceras (Bostrychoceras) polyplocum (Roemer, 1841) (see in particular Kennedy and Kaplan 1997, p. 52, pl. 39, fig. 4; pl. 41, figs 1, 9; pl. 43, figs 1, 4­5; pls 44, 46). The last three whorls (W1­W3) of MMG NsK 3 (Text-fig. 6D) are comparable with the bituberculate last whorl of the adult macroconch of N. (B.) polyplocum of Kennedy and Kaplan (1997, pl. 48); however, W3 displays a collared constriction in the present individual. Similarly, bituberculate whorls of the early growth stage of N. (D.) wernickei of a Wh smaller than 22 mm (e.g., BGR MA 14523; see Text-fig. 5D) are quite similar to N. (B.) polyplocum of Kennedy and Kaplan (1997, pl. 40, figs 1­4, 6­7; pl. 42, figs 1, 3­5, 7; pl. 43, figs 2, 3), which was subsequently referred to as Nostoceras (Didymoceras) sp. 1 by Küchler and Odin (2001). It is not possible to assign isolated fragments of helicoidal whorls of the middle and early growth stages between Wh 9­54 mm to one of these nostoceratid taxa. Nostoceras (Bostrychoceras) polyplocum Stemwede 1 and Hannover 2, Germany body chamber maximum vL Wh Rr Ri shape tuberculation constrictions ribs 150 mm 38­65 mm 6.3 7­8 irregular, short hook 2 ventral rows, irregular apertural dense simple primaries, identical to helicoidal part 140 mm 42­64 mm 4.5 10 medium C-shaped 2 ventral rows, irregular apertural simple primaries, similar to helicoidal part 300 mm 40­70 mm 4.5­11.5 6­11 medium to large C-shaped 2 ventral rows, irregular apertural macroconchs: distant coarse primaries, few bifurcations microconchs: simple primaries, similar to helicoidal part 285 mm 32­45 mm 7.7­9.5 5­9 large U-shaped Nostoceras (Didymoceras) postremum, holotype Vistula River Valley, Poland 3 Nostoceras (Didymoceras) postremum Hannover, Germany 2 Nostoceras (Didymoceras) wernickei Lüneburg, Germany 4 2 ventral rows, regular none distant coarse primaries, few bifurcations helicoidal part Wh Wb/Wh Rr Ri coiling tuberculation constrictions ribs W5­W1 = 10­56 mm 0.54­1 2.7­3.3 11­13 early: loosely, mid: close early: bituberculate, mid: mostly nontuberculate few dense simple primaries, few bifurcations W1 = 42­50 mm 0.8­0.9 2.0­3.1 10­13 loosely mid: uni- to bituberculate, very weak none dense simple primaries, few bifurcations W4­W1 = 27­50 mm 0.5­0.72 4.8 6­11 loosely early: bituberculate, mid: nontuberculate none dense simple primaries W6­W1 = 9­54 mm 0.5­1 1.2­4.5 11­19 loosely early: bituberculate, mid: nontuberculate none, or 1­3 per whorl dense simple primaries Table 2. Comparison of Nostoceras (Bostrychoceras) polyplocum, N. (Didymoceras) postremum and N. (Didymoceras) wernickei from Germany and Poland; according to 1 Kennedy and Kaplan (1997), 2 Niebuhr (2004), 3 Blaszkiewicz (1980), 4 the present paper At Lüneburg, helicoidal parts of up to four whorls are associated exclusively with distinct, only loosely connected U-shaped body chambers of N. (D.) wernickei. The very short body chamber of N. (B.) polyplocum is closely associated with the last phragmocone whorl and therefore often preserved attached in large suites from the "Haldemer Schichten" at Stemweder Berg (Kennedy and Kaplan 1997), the Lehrte West Syncline near Hannover (Küchler and Schneider 2013) and Tercis les Bains, southwest France (Küchler and Odin 2001). However, polyplocum-like body chambers are unknown from Lüneburg, and therefore, it is assumed that contemporary nostoceratid helicoid whorls are conspecific with N. (D.) wernickei. Nostoceratid heteromorphs develop a change of approximately 90 degrees in their direction of growth in transition from the septate helicoidal whorls to the hook. As defined for Nostoceras (Didymoceras) (see Wright et al. 1996, p. L247) the middle and final portions of body chambers have their characteristic two rows of tubercles in a ventral position. In the older portion of body chambers (transitional part; see Text-figs 1­4), venter and tuberculation shift to the external side of the whorl. In the Lüneburg material, this phenomenon was referred to as "twisted whorls" ["verdrehte Windungen"] by Wollemann (1902, p. 95) and "torsion of the body chamber" ["Torsion der Wohnkammer"] by Wiedmann (1962, p. 209). Associated are irregularities in ribbing and tuberculation, i.e., bifurcation of ribs ["Gabelung" of Wollemann 1902, p. 95]. These features are lacking in the "species" wernickei of the genera Hamites, Anisoceras, Neancyloceras and Pseudoxybeloceras to which the authors listed above referred the material. The transitional part with torsion clearly Text-fig. 3. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) from the Zeltberg Quarry at Lüneburg, northern Germany. A ­ BGR MA 14515; U-shaped body chamber with transitional part, bituberculate and with delicate, regular ribbing. B­C ­ BGR MA 14514, neotype; U-shaped body chamber with adult aperture and beginning of transitional part, bituberculate and of delicate, regular ribbing, and ventral view of the curved portion of the body chamber, respectively. All specimens are natural size Text-fig. 4. Reillustration of Nostoceras (Didymoceras) postremum (Blaszkiewicz, 1980) from the Lehrte West Syncline near Hannover (Niebuhr 2004, pl. 1). BGR MA 13592; A ­ lateral view; B ­ ventral view of a complete, C-shaped body chamber with adult aperture, transitional part with bifurcation of ribs as well as younger portions of the last whorl; largest known specimen (D = 200 mm), bituberculate and with delicate, regular ribbing; note break between body chamber and helicoidal part. Both views are × 0.75 demonstrates that wernickei belongs to the Nostoceratidae. However, large bituberculate, U-shaped body chamber fragments without torsion, as illustrated by Pervinquière (1907, pl. 3, fig. 33), Naidin in Krymgolts (1974, pl. 57, fig. 3) and Kennedy and Summesberger (1984, pl. 10, fig. 1 only) look quite similar and are barely distinguishable from the middle and final portions of nostoceratid body chambers. The localities from which the authors listed above recorded their material also yielded other nostoceratid taxa [in part associated with typical N. (B.) polyplocum; see, in particular, Kennedy and Summesberger 1984, pl. 9, figs 4, Text-fig. 5. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) from the Zeltberg Quarry at Lüneburg, northern Germany; helicoidal parts. A ­ BGR X 13000; three nontuberculate whorls (W1­W3) of the loosely coiled middle growth stage, five collared constrictions visible. B­C ­ BGR X 13002; nontuberculate whorl of the middle growth stage, in lateral and top views, respectively. D ­ BGR MA 14517; nontuberculate last whorl (W1) and fragment of W2 of the middle growth stage. E ­ BGR MA 14523; bituberculate whorl of the loosely coiled early growth stage; septum visible. All specimens are natural size 8, 13­14] and several other index ammonites of late late Campanian age. Therefore, it is most likely that N. (D.) wernickei also appears in Upper Austria, Tunisia and the Donbass region. Furthermore, Mikhailov (1951, pl. 1, fig. 1 = ?), Wiedmann (1962, pl. 12, fig. 5 = ?), Klinger (1976, pl. 33, fig. 4 = ?), Kennedy and Summesberger [1984, pl. 6, fig. 3 = Lewyites elegans (Moberg, 1885); pl. 9, figs 6­7 = Oxybeloceras aff. crassum (Whitfield, 1877); pl. 10, figs 8­9 = ?] and Kaplan et al. (1996, pl. 35, figs 6­7 = ?) figured at least five different polyptychoceratines under the species name wernickei. Although Wollemann (1902) assigned his material to the genus Hamites, he discussed at length similarities to Heteroceras polyplocum, as follows, "Einzelne zusammengedrückte und verdrehte Windungen der mit Knoten versehenen Form des Heteroceras polyplocum sind unserem Hamiten bisweilen sehr ähnlich" and "Einige Bruchstücke ... [of his Heteroceras polyplocum] ... haben durch Verdrückung und Verdrehung eine Hamites-artige Gestalt angenommen und wurden deshalb im Lüneburger Museum unter der Bezeichnung Hamites und Helicoceras aufbewahrt" (Wollemann 1902, pp. 95, 97). However, all subsequent authors adopted Wollemann's (1902) first familial assignment. Consequently, the specific name wernickei is no longer available for Polyptychoceratinae. The present U-shaped body chambers of N. (D.) wernickei are similar to hooks of Didymoceras cheyennense (Meek and Hayden, 1856) from the Western Interior of the United States (see Kennedy et al. 2000). However, in that species shafts are shorter, the youngest Text-fig. 6. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) from the Zeltberg Quarry at Lüneburg, northern Germany; helicoidal parts. A ­ SM 48; half a whorl of the middle growth stage, older portion nontuberculate and younger portion bituberculate. B ­ SM 31; weakly bituberculate whorl of the loosely coiled early growth stage. C ­ SM 49; two nontuberculate whorls (W2­W3) of the middle growth stage, more tightly coiled, septa visible; note that both sides of W3 are broken. D ­ MMG NsK 3; four whorls (W1­W4) of the middle growth stage, more tightly coiled, W1 and W2 bituberculate, W3 and W4 nontuberculate but with collared constrictions. All specimens are natural size parts with adult aperture are approximated so that the opening between shafts is oval rather than U-shaped. Furthermore, the early and middle growth stages are utterly different, both in coiling and ornament. We also note that the helicoidal parts of N. (D.) wernickei differ from those of most species of Didymoceras in comprising more whorls in the middle growth stage (W1­W4), and in the successive part of the early growth stage (W5­W6) Text-fig. 7. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) from the Zeltberg Quarry at Lüneburg, northern Germany. SM 42; recently in the exibition of the Museum Lüneburg; largest helicoidal portion known, consisting of four mostly nontuberculate whorls (W1­W4) of the loosely coiled middle growth stage, W3 having a few weak tubercles of the lower row. Natural size whorls are regularly openly coiled. For that reason, we consider N. (D.) wernickei to be a discrete species. STRATIGRAPHY AND DISTRIBUTION: In addition to the occurrence at Lüneburg (bipunctatum/roemeri Zone; upper upper Campanian), N. (D.) wernickei probably appears in the upper Campanian of the Gschliefgraben (Upper Austria), Tunisia and the Donbass region. terruptum (Schlüter); Küchler, pl. 12, figs 9, 10 only [non pl. 12, figs 4­8 = Polyptychoceratinae sp. indet.]. 2001. Oxybeloceras sp.; Kennedy and Odin, p. 481, pl. 2, fig. 17. 2006. Oxybeloceras aff. crassum (Whitfield, 1877); Jagt and Neumann, p. 567, fig. 1A­C. 2013. Oxybeloceras aff. crassum (Whitfield, 1877); Jagt, p. 138, fig. 1. Family Diplomoceratidae Spath, 1926 Subfamily Polyptychoceratinae Matsumoto, 1938 Genus Oxybeloceras Hyatt, 1900 TYPE SPECIES: Ptychoceras crassus Whitfield, 1877, by original designation. DIAGNOSIS: Two straight shafts in hairpin-like, tight contact except for tear-shaped, narrow opening at the elbow linking shafts; narrow, sharp ribs bear two rows of small ventral tubercles; constrictions lacking. REMARKS: Wright et al. (1996, p. L255) regarded Oxybeloceras as a synonym of Solenoceras Conrad, 1860; however, this view is not adopted here. MATERIAL: The original of Wollemann (1902, pl. 4, fig. 5), in the BGR Berlin-Spandau collection (BGR X 5873), of which MMG NsK 4 and NHMM 2015 019 are plaster casts. The specimen comes from the Zeltberg Quarry at Lüneburg, Niedersachsen, northern Germany, from the "blauer Mergel" (as noted on the associated label) of the "Heteroceras-Schicht des MucronatenSenons", i.e., upper upper Campanian (bipunctatum/roemeri Zone). DESCRIPTION: The single specimen from Lüneburg (Text-fig. 8A­B), preserved as a composite mould, attains an overall length of 45 mm and consists of two straight, parallel limbs in close approximation, both limbs preserved for equal lengths and Wh c. 7 mm. The curved sector, with an elbow diameter of 14.2 mm, is associated with a small, elongate, teardrop-shaped opening; early whorls and aperture are missing. The ornament consists of strong, straight ribs, Ri = 3.5­4; ?each rib (probably due to poor preservation; compare Wollemann 1902, p. 95) has a weak, inconspicuous bullate ventrolateral tubercle. Ribs are straight and prorsiradiate on the smaller limb, rectiradiate on the curved sector and rursiradiate and more widely spaced on the larger limb, weakening on the venter. No constrictions or sutures seen. DISCUSSION: Two straight, hairpin-like, closely adpressed shafts and a tear-shaped opening associated with the curved sector are characteristic of the genus Oxybeloceras and differentiate it from Pseudoxybeloceras (Parasolenoceras). In addition, species of Solenoceras are similar, albeit often bear constrictions. Oxybeloceras aff. crassum is not common in northern Germany. To date merely a handful of specimens are known (Wollemann 1902; Jagt and Neumann 2006; Jagt 2013). The three specimens from the Lehrte West Syncline near Hannover (one of which is refigured here in Text-fig. 8C), are closely comparable in size and general habitus to Wollemann's individual, with overall lengths of 38.5 mm, 85.5 mm and 56 mm, elbow diameters of 15.5 mm, 18 mm and 10 mm and Ri = c. 4). Jagt and Neumann (2006) and Jagt (2013) discussed at Oxybeloceras aff. crassum (Whitfield, 1877) (Text-fig. 8) pars * 1902. Hamites Wernickei Wollemann, p. 95, pl. 4, fig. 5 only [non pl. 4, fig. 4; pl. 5, figs 1, 2 = Nostoceras (Didymoceras) wernickei (Wollemann, 1902)]. 1976. Solenoceras wernickei (Wollemann, 1902); Klinger, p. 73. non 1976. Neancyloceras sp. cf. Neancyloceras wernickei (Wollemann), 1902; Klinger, p. 73, pl. 33, fig. 4; text-figs 8i, 10f (= Polyptychoceratinae sp. indet.). pars 1984. Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902); Kennedy and Summesberger, p. 166, pl. 9, figs 6, 7 only [non pl. 6, fig. 3 = Lewyites elegans (Moberg, 1885); pl. 10, fig. 1 = ?Nostoceras (Didymoceras) wernickei (Wollemann, 1902); pl. 10, figs 8, 9 = Polyptychoceratinae sp. indet.]. 1984. Pseudoxybeloceras (Parasolenoceras) interruptum (Schlüter, 1872); Kennedy and Summesberger, p. 167, pl. 6, figs 5, 10, 11. 2000. Pseudoxybeloceras (Parasolenoceras) ?wernickei (Wollemann); Küchler, pl. 12, figs 1­3. pars 2000. Pseudoxybeloceras (Parasolenoceras) cf. in- Text-fig. 8. Oxybeloceras aff. crassum (Whitfield, 1877). A ­ Reillustration of Hamites wernickei of Wollemann (1902, pl. 4, fig. 5) from the Zeltberg Quarry at Lüneburg, northern Germany; natural size. B ­ BGR X 5873, holotype, the original of Wollemann (1902, pl. 4, fig. 5); two parallel shafts of equal length and whorl height and the connecting curved sector (note subsequent damage to the latter); natural size. C ­ Reillustration of Oxybeloceras aff. crassum (Whitfield, 1877) of Jagt (2013, fig. 1) from the Lehrte West Syncline near Hannover, minor/polyplocum Zone (C. Holschemacher Collection, Berlin); two parallel shafts of unequal length and whorl height and the connecting curved sector; × 1.5 length the affinities to the North American species Oxybeloceras crassum (Whitfield, 1877) and Spiroxybeloceras kimbroense Kennedy and Cobban, 1999, which both are close in style of ribbing, rib index and general habitus. Jagt and Neumann (2006) remarked that the limited material from the Lehrte West Syncline near Hannover (MAB 3290a­b; C. Holschemacher Collection, Berlin) appeared to have less closely spaced ribbing on the smaller limb and a less regular occurrence of ventrolateral tubercles. Material from other European countries (see below) also is rare and of mediocre preservation, but it would appear that the size of the teardrop-shaped opening is similar to that in specimens of O. crassum from the upper Campanian of Montana, Wyoming and Colorado, and rib density overlaps. For now, we prefer to keep this form in open nomenclature until better-preserved material becomes available. STRATIGRAPHY AND DISTRIBUTION: Apart from the Lüneburg specimen from the bipunctatum/roemeri Zone (upper upper Campanian), O. aff. crassum is known from the uppermost lower to lowermost lower upper Campanian (upper vulgaris/stolleyi to minor/polyplocum zones) of the Lehrte West Syncline near Hannover, northern Germany; the lower upper Campanian (Pseudoxybeloceras Zone) of Tercis les Bains, southwest France; the upper upper Campanian (polyplocum to pulcherrimus zones) of Navarra, northern Spain, and the upper Campanian of the Gschliefgraben, Upper Austria. CONCLUSIONS In view of the fact that the species name wernickei (of Wollemann 1902) is here restricted to three (out of four) of the originally illustrated late late Campanian (bipunctatum/roemeri Zone) heteromorphs from the Zeltberg Quarry (Lüneburg, northern Germany) that have irregularities of ribbing and tuberculation and a change in direction of growth at the transition from the helicoidal whorls to the hook, the single hairpin-shaped diplomoceratid (polyptychoceratine) specimen is in need of a new name. The former are assigned to the subfamily Nostoceratinae as Nostoceras (Didymoceras) wernickei (Wollemann, 1902) comb. nov., while the latter is referred to as Oxybeloceras aff. crassum (Whitfield, 1877). Comparison with previous records of heteromorph taxa under the name of wernickei demonstrates that the geographic range of N. (D.) wernickei probably also included Upper Austria (Gschliefgraben), Tunisia and the Donbass region; O. aff. crassum is known from the Hannover area (northern Germany), southeast France, northern Spain and Upper Austria (Gschliefgraben). Acknowledgements We wish to thank to J. Erbacher (BRG, Hannover) and A. Ehling (BGR, Berlin-Spandau) for access to material in their care, to D. Schumacher (Lüneburg) for donating his specimens from the Zeltberg Quarry at Lüneburg and for assisting with field work, images and measurements, to C. Holschemacher (Berlin) for making material from the Hannover area available for study, and to M. Röthel and R. Winkler (SNSD) for preparatory and photographic assistance. W.J. Kennedy (Oxford, U.K.) and H.C. Klinger (Cape Town, South Africa) are thanked for constructive comments on an earlier typescript. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Acta Geologica Polonica de Gruyter

Revision of Hamites wernickei Wollemann, 1902 (Cephalopoda, Ancyloceratina) from the classic Lüneburg section (Upper Cretaceous, northern Germany)

Acta Geologica Polonica , Volume 66 (4) – Dec 1, 2016

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Abstract

Niebuhr, B. and Jagt, J.W.M. 2016. Revision of Hamites wernickei Wollemann, 1902 (Cephalopoda, Ancyloceratina) from the classic Lüneburg section (Upper Cretaceous, northern Germany). Acta Geologica Polonica, 66 (4), 627­644. Warszawa. A re-examination of heteromorph ammonites of late Campanian age from the Zeltberg section at Lüneburg has demonstrated that the type series of Hamites wernickei in fact comprises two different species that are here assigned to the nostoceratid Nostoceras Hyatt, 1894 and the polyptychoceratid Oxybeloceras Hyatt, 1900. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) comb. nov., to which three of the four specimens that were described and illustrated by Wollemann (1902) belong, has irregularities of ribbing and tuberculation and changes its direction of growth at the transition from the helicoidal whorls to the hook, which is a typical feature of members of the subfamily Nostoceratinae. Torsion of body chambers is not developed in hairpin-shaped ammonite species, which means that the species name wernickei is no longer available for such polyptychoceratine diplomoceratids. Consequently, the fourth specimen figured and assigned to Hamites wernickei by Wollemann (1902) is here transferred to Oxybeloceras and considered conspecific to material from the Hannover area (Lehrte West Syncline) as O. aff. crassum (Whitfield, 1877). In addition to the "Heteroceras-Schicht des Mucronaten-Senons" of Lüneburg (bipunctatum/roemeri Zone, upper upper Campanian), the geographic range of N. (D.) wernickei probably includes Upper Austria, Tunisia and the Donbass region, while O. aff. crassum is known from the Hannover area (northern Germany), southern France, northern Spain and Upper Austria. Key words: Campanian; Ammonites; Nostoceras; Oxybeloceras; Taxonomy; Europe. INTRODUCTION Wollemann (1902) described and illustrated a suite of ammonite species that he had collected at the Zeltberg Quarry of Lüneburg (Niedersachsen, c. 30 km southsouth-east of Hamburg, northern Germany) at the end of the nineteenth century. Notable are bituberculate heteromorphs which he assigned to a new species, Hamites wernickei (see Wollemann 1902, p. 95). Wollemann noted that, "The sculpture is so simple and characteristic that, on the basis of this, the species is easily recognised and differentiated from Hamites species already known" ["Die Sculptur ist so einfach und charakteristisch, dass die Art leicht an dieser erkannt und von den bereits bekannten Hamites-Arten unterschieden werden kann"]. The type series of Wollemann's new species falls into two size categories: I. three large-sized specimens represent well-separated, U-shaped curved portions of bituberculate hetero- morphs (i.e., Wollemann 1902, pl. 4, fig. 4; pl. 5, figs 1, 2), and II. a single small, hairpin-like specimen develops approximated parallel shafts, originally interpreted as the inner portions of a polyptychoceratid ["innere Windung" sensu Wollemann 1902, p. 95, pl. 4, fig. 5]. Subsequent records of heteromorph ammonites under the name of wernickei were either not figured (e.g., Diener 1925; Poaryski 1948; Wiedmann 1964; Klinger 1982; Kaplan et al. 2005), showed unequivocally different species of the subfamily Polyptychoceratinae [e.g., Mikhailov 1951; Wiedmann 1962; Klinger 1976; Tzankov 1982; Kennedy and Summesberger 1984 (in part); Lommerzheim 1995; Kaplan et al. 1996; Küchler 2000] or were species of indeterminate familial assignment [Pervinquière 1907; Naidin in Krymgolts 1974; Kennedy and Summesberger 1984 (in part)]. In most cases, what authors understood to represent the species named wernickei were the three large U-shaped curved individuals from the type series (Wollemann 1902, pl. 4, fig. 4; pl. 5, figs 1, 2) (see e.g., Pervinquière 1907; Mikhailov 1951; Wiedmann 1962; Naidin in Krymgolts 1974; Klinger 1976; Tzankov 1982). Küchler (2000) even included the small hairpin-like specimen (Wollemann 1902, pl. 4, fig. 5) in it. Kennedy and Summesberger (1984, p. 167) adopted the species name wernickei for both size categories, I (i.e., larger specimens of Kennedy and Summesberger 1984, pl. 10, figs 1, 9) and II (i.e., small specimens of Kennedy and Summesberger 1984, pl. 9, figs 6, 7), listing it as Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902). However, they did not include the small specimen figured by Wollemann (1902, pl. 4, fig. 5) in their size category II, yet discussed the possibility that it, "may be better referred to `Hamites' interruptus Schlüter, 1872". In our opinion, the four specimens illustrated under the name wernickei by Wollemann (1902) in fact belong to two different families, genera and species, as follows. Species I. Of the three large heteromorphs illustrated in his pl. 4, fig. 4 and pl. 5, figs 1 and 2, Wollemann (1902) noted that, "A few compressed and twisted whorls of the tuberculate Heteroceras polyplocum are at times quite similar to our hamitid" ["Einzelne zusammengedrückte und verdrehte Windungen der mit Knoten versehenen Form des Heteroceras polyplocum sind unserem Hamiten bisweilen sehr ähnlich"]. All three distinctly Ushaped specimens of Wollemann (1902) develop a change in direction of growth ["deutliche Torsion der Wohnkammer", sensu Wiedmann 1962, p. 209] and irregularities of ribbing and tuberculation which are missing in polyptychoceratines, yet are characteristic of the Nostoceratinae. Although Wollemann (1902, p. 96) noted that the large-sized heteromorphs, named wernickei, ap- peared to be relatively common together with his Heteroceras polyplocum ["zh. = ziemlich häufig, MH. = Heteroceras-Schicht des Mucronaten-Senons"], additional, similarly shaped "Hamites" specimens have never been recovered subsequently, not in large suites of Polyptychoceratinae from the Lehrte West Syncline near Hannover (Niebuhr et al. 1997; Niebuhr 2004; Jagt 2013), nor in the "Haldemer Schichten" at the Stemweder Berg (Kennedy and Kaplan 1997), the Münsterland Cretaceous Basin (Lommerzheim 1995; Kaplan et al. 2005), Tercis les Bains, southwest France (Odin et al. 2001) and the Vistula River Valley, Poland (Blaszkiewicz 1980). Kaplan et al. (2005, pp. 30, 43) recorded Pseudoxybeloceras (Parasolenoceras) wernickei from older strata in the southeastern part of the Münsterland Cretaceous Basin (i.e., Beckum Member, Coesfeld Formation; lowermost upper Campanian), but failed to illustrate the single specimen available to them. Poaryski (1948) had earlier noted "Hamites wernickei Woll." from the Polish Didymoceras donezianum Zone (equivalent to the north German bipuctatum/roemeri Zone; upper upper Campanian), but did not provide an illustration either. However, these records were not confimed by Blaszkiewicz (1980). Wiedmann (1962, p. 209) designated as lectotype of wernickei the original of Wollemann (1902, pl. 5, fig. 1). Later, Kennedy and Summesberger (1984, p. 166), apparently unaware of Wiedmann's prior designation, selected the original of Wollemann's pl. 4, fig. 1 as lectotype (actually a gastropod; it should have stated pl. 4, fig. 4); this is an error. It seems clear that all three authors understood the species name wernickei to be applicable to large-sized, U-shaped heteromorphs (Wollemann 1902, pl. 4, fig. 4; pl. 5, figs 1, 2). Unfortunately, the Wollemann Collection which was housed at the museum and the "Altes Kaufhaus" of Lüneburg was destroyed in a fire in December 1959 (i.e., predating Wiedmann's lectotype designation). In other words, Wiedmann's lectotype is lost. However, in the collection of the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, two U-shaped body chambers and c. 20 fragments of the coiled portion of wernickei from the Zeltberg Quarry in Lüneburg are kept, collected in 1956 and 1980 by Friedrich Schmid. Furthermore, in the BGR BerlinSpandau collection, the collection of the Senckenberg Naturhistorische Sammlungen Dresden and in the collection of D. Schumacher (Lüneburg), are six, one and seven fragments of the coiled portion with up to four whorls in contact, respectively. These specimens are here described and illustrated for the first time. Species II. The original of the small, hairpin-like specimen of Wollemann (1902, pl. 4, fig. 5) is housed in the BGR Berlin-Spandau collection. It clearly is a member of the subfamily Polyptychoceratinae. Conspecific material is known from the upper Campanian of the Hannnover area (northern Germany), as described and illustrated by Jagt and Neumann (2006), in open nomenclature [Oxybeloceras aff. crassum (Whitfield, 1877); see also Jagt 2013]. The size of the teardrop-shaped opening is similar to that in material from the upper Campanian of Montana, Wyoming and Colorado, and rib density overlaps. Jagt and Neumann (2006) remarked that the limited material from the Lehrte West Syncline near Hannover (MAB 3290a­b; C. Holschemacher Collection, Berlin) appeared to have less closely spaced ribbing on the smaller limb and a less regular occurrence of ventrolateral tubercles. For now, we prefer to keep this form in open nomenclature until better-preserved material becomes available. the collections from the "Heteroceras-Schicht des Mucronaten-Senons" at Lüneburg. REPOSITORIES OF MATERIAL BGR MA: Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover, Germany. BGR X: Bundesanstalt für Geowissenschaften und Rohstoffe, Berlin-Spandau, Germany. MAB: Oertijdmuseum De Groene Poort, Boxtel, the Netherlands. MMG: Senckenberg Naturhistorische Sammlungen Dresden, Museum für Mineralogie und Geologie, Sektion Paläozoologie, Dresden, Germany. MN: Museum für Naturkunde, Berlin, Germany. NHMM: Natuurhistorisch Museum Maastricht, Maastricht, the Netherlands. SH: Detlef Schumacher Collection, Lüneburg, Germany. ASSOCIATED AMMONITE FAUNA AND BIOSTRATIGRAPHY In addition to N. (D.) wernickei and O. aff. crassum, as here interpreted, Wollemann (1902) mentioned from the "Heteroceras-Schicht des Mucronaten-Senons" (as recently identified by one of us, BN): Menuites wittekindi (Schlüter, 1872), Menuites portlocki portlocki (Sharpe, 1855), Hoploscaphites greenlandicus (Donovan, 1953) and Gaudryceras mite (von Hauer, 1866). "Heteroceras polyplocum A. Roemer sp." of Wollemann (1902) does not belong to Nostoceras (Bostrychoceras) polyplocum (Roemer, 1841), but rather refers to the helicoidal portions of N. (D.) wernickei (see below). Furthermore, Pseudoxybeloceras (Parasolenoceras) interruptum (Schlüter, 1872), Lewyites elegans (Moberg, 1885) and Hoploscaphites compressus (Roemer, 1841) have recently been identified from upper Campanian strata exposed at the Zeltberg Quarry (Niebuhr, in prep.). Large-sized species of Nostoceras (Didymoceras), in association with M. wittekindi, M. p. portlocki, Ps. (Pa.) interruptum, H. greenlandicus and H. compressus, are typical of the bipunctatum/roemeri Zone (upper upper Campanian) of the Lehrte West Syncline near Hannover (Niedersachsen, northern Germany, c. 100 km south of Lüneburg). Lewyites elegans first appears in the lower upper Campanian and ranges into the bipunctatum/roemeri Zone (Niebuhr 1996, 2004; Niebuhr et al. 1997, p. 223; Küchler and Schneider 2013). Gaudryceras mite is a long-ranging taxon, with records from Turonian to Maastrichtian strata (Kennedy and Summesberger 1979; Summesberger and Kennedy 1996). Only the upper upper Campanian is indicated in SYSTEMATIC PALAEONTOLOGY Abbreviations used are as follows: D ­ diameter; vL ­ ventral length of nostoceratids, measured between lower and upper rows of tuberculation; Ah ­ apertural height; Wh ­ whorl height; Wb ­ whorl breadth; Ri ­ rib index, number of ribs in a distance equal to the whorl height; Rr ­ rib ratio, ventral length divided by rib number. Order Ammonoidea von Zittel, 1884 Suborder Ancyloceratina Wiedmann, 1966 Superfamily Turrilitoidea Gill, 1871 Family Nostoceratidae Hyatt, 1894 Subfamily Nostoceratinae Hyatt, 1894 Genus Nostoceras Hyatt, 1894 TYPE SPECIES: Nostoceras stantoni Hyatt, 1894 = Ancyloceras? approximans Conrad, 1855, by original designation of Hyatt (1894, p. 569). REMARKS: The classification of Wright et al. (1996, p. L245) is followed here. Subgenus Didymoceras Hyatt, 1894 TYPE SPECIES: Ancyloceras? nebrascensis Meek and Hayden, 1856, by original designation of Hyatt (1894, p. 574). DIAGNOSIS: Early growth stage of either loose and ir- regular helical coils or straight limbs connected by elbows, even hamitoid; followed by a middle growth stage of helical whorls just touching or not so; body chamber in a retroversal whorl, U- or C-shaped. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) comb. nov. (Text-figs 1­3, 5­7) pars * 1902. Hamites Wernickei Wollemann, p. 95, pl. 4, fig. 4; pl. 5, figs 1­2 [non pl. 4, fig. 5 = Oxybeloceras aff. crassum (Whitfield, 1877)]. ? 1907. Hamites (Anisoceras?) Wernickei Wollemann; Pervinquière, p. 86, pl. 3, fig. 33. non 1951. Anisoceras wernickei Wollemann; Mikhailov, p. 40, text-fig. 9, pl. 1, fig. 1 (= Polyptychoceratinae sp. indet.). non 1962. Neancyloceras wernickei (Wollemann); Wied- mann, p. 209, pl. 12, fig. 5 (= Polyptychoceratinae sp. indet.). ? 1974. Neancyloceras wernickei (Wollemann, 1902); Naidin in Krymgolts, p. 169, pl. 57, fig. 4. non 1976. Neancyloceras sp. cf. Neancyloceras wernickei (Wollemann), 1902; Klinger, p. 73, pl. 33, fig. 4; text-figs 8i, 10f (= Polyptychoceratinae sp. indet.). ? 1984. Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902); Kennedy and Summesberger, p. 166, pl. 10, fig. 1 only. non 1984. Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902); Kennedy and Summesberger, p. 166, pl. 6, fig. 3 [= Lewyites elegans (Moberg, 1885)]; pl. 9, figs 6­7 [= Oxybeloceras aff. crassum (Whitfield, 1877)]; pl. 10, figs 8­9 (= Polyptychoceratinae sp. indet.). non 1995. Pseudoxybeloceras (Parasolenoceras)(?) cf. wernickei (Wollemann, 1902); Lommerzheim, Text-fig. 2. Nostoceras (Didymoceras) wernickei (Wollemann, 1902); reillustration of Hamites wernickei of Wollemann (1902, pl. 5, fig. 1); U-shaped body chamber with adult aperture, transitional part with torsion and bifurcation of ribs. Natural size Text-fig. 1. Nostoceras (Didymoceras) wernickei (Wollemann, 1902). A­B ­ Reillustration of Hamites wernickei of Wollemann (1902, pl. 5, fig. 2); adult bituberculate specimen with complete U-shaped body chamber and younger portions of the last whorl; note torsion of transitional part and break between body chamber and helicoidal part, and ventral view of the same, respectively, showing details of the transitional part with rib bifurcation. C ­ Reillustration of Hamites wernickei of Wollemann (1902, pl. 4, fig. 4); U-shaped body chamber and transitional part with torsion and bifurcation of ribs. All specimens are natural size p. 68, pl. 7, figs 5­6a-c (= Polyptychoceratinae sp. indet.). non 1996. Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902); Kaplan et al., p. 41, pl. 35, figs 6­7 (= Polyptychoceratinae sp. indet.). non 2000. Pseudoxybeloceras (Parasolenoceras) ?wernickei (Wollemann); Küchler, pl. 12, figs 1­3 [= Oxybeloceras aff. Crassum (Whitfield, 1877)]. DIMENSIONS: Collection number pl. 4, fig. 4 pl. 5, fig. 1 pl. 5, fig. 2 Growth stage late late late, middle BGR MA 14514 BGR MA 14515 BGR MA 14520 BGR MA 14518 BGR MA 14516 BGR MA 14517 BGR MA 14519 SH 42 late late mid., W1 mid., W1 mid., W1 mid., W1 mid., W1 middle, W1­W4 Tubercles, swellings, constrictions bituberculate bituberculate bituberculate ?nontuberculate bituberculate bituberculate nontuberculate nontuberculate nontuberculate nontuberculate nontuberculate W4: nontub. W3: ?lower row W2: nontub. W1: nontub. BGR X 13000 middle, W1­W3 nontuberculate, 5 constrictions > 270 mm > 280 mm vL of body chamber > 215 mm > 280 mm 285 mm TYPES: Lectotype, designated by Wiedmann (1962, p. 209), was the original of Wollemann (1902, pl. 5, fig. 1; reillustrated here as Text-fig. 2) which had been lost in December 1959. To replace this we here designate a neotype, BGR MA 14514. Locus typicus is the Zeltberg Quarry at Lüneburg, Niedersachsen, northern Germany. Stratum typicum is the "Heteroceras-Schicht des Mucronaten-Senons" of Wollemann (1902), which is the equivalent of the bipunctatum/roemeri Zone (upper upper Campanian), c.1.5 myr below the CampanWh of body chamber 36 mm 43­45 mm 38­44 mm 34 mm 32­38 mm 32­41 mm 54 mm 53 mm 50 mm 49 mm 48 mm W4: 31 mm W3: 38 mm W2: 46 mm W1: 46 mm W3: 24 mm W2: 33 mm W1: 42 mm 0.8 0.6 0.5 0.5 0.5 0.6 4.0 2.5 2.8 3.8 3.4 3.4 11.5 13 14 13 11 12 0.9 Wh of helicoidal whorl Wb/Wh Rr (vL/ribs) 7.7 8.5 8.3 3.0 9.3 9.5 2.8 4.5 4 3.3 3.4 2.6 3.1 12 12.5 Ri (ribs equal Wh) 5­7 7­9 7.5 11 5.5 5.5 19 15 13 14 BGR X 13001 middle, W1­W2 nontuberculate W2: 37 mm W1: 41 mm MMG NsK 3 early, W4 middle, W1­W3 W4: ? W1­W3: bituberculate, W3: constriction few swellings older: nontub., younger: bitub. W4: >14 mm W3: 22 mm W2: 33 mm W1: 40 mm 26­40 mm 33­39 mm 0.9­1 2.6 2.5 3.3 2.3­3.3 3.0 9 11 12 12 12.5 SH 49 SH 48 middle mid., W1 BGR X 13002 BGR MA 14523 BGR MA 14521 SH 41 SH 31 mid., W3 early early early early nontuberculate bituberculate bituberculate nontuberculate bituberculate 22­28 mm 18­22 mm 16 mm 15 mm 9­10 mm 0.7­0.6 0.7­0.8 0.8 1.1 0.8­1 2.2 1.8 1.4 3.5 1.2­1.8 11 13 13 7 9­10 Table 1. Dimensions of Nostoceras (Didymoceras) wernickei (Wollemann, 1902). Grey: Wollemann's (1902) specimens; bold: BGR MA 14514, designated neotype ian/Maastrichtian boundary (compare Niebuhr et al. 2011). MATERIAL: In addition to the neotype (BGR MA 14514, see above), one U-shaped body chamber (BGR MA 14515) and approximately 25 fragments of helicoidal whorls (e.g., BGR MA 14516­14523; BGR X 13000­13006; MMG NsK 3; and SH 31, SH 41­42, SH 48­49). DESCRIPTION: Nostoceras (D.) wernickei is both sinistrally (Text-figs 1A­B, 2, 3B­C) and dextrally coiled (Text-fig. 1C). Phragmocone and body chamber whorls have Wb/Wh ratios of 0.5­1. Adult body chambers are distinctly U-shaped, enlarged towards the aperture and may become pipe-like; weak collared constrictions can appear. Rib indices of body chambers are 5­9, while in helicoidal whorls they may reach 11­19 (with a mean value of 13). Rib ratios show the same differentiation: phragmocones of the middle growth stage are more finely ribbed with ratios smaller than 4.5, while more coarsely ribbed body chambers have ratios of 7.5­9.5 (Table 1). The change in ribbing density appears abruptly (see Text-fig. 1A). The three body chambers illustrated by Wollemann (1902, reillustrated here in Text-figs 1­2) and the two completely preserved body chambers housed in the BGR Hannover collection (Text-fig. 3) are quite similar with two c. 60 mm-long, near-parallel shafts separated by a 20­30 mm wide opening between them. The curved sector connecting the shafts is subcircular. This habitus of body chambers has led previous authors to refer this species to the Polyptychoceratinae. The three specimens of Wollemann (1902) (see Text-figs 1­ 2) and one of the BGR Hannover individuals (Text-fig. 3B) show the torsion of the transitional part. The body chambers and transitional parts bear coarse, distant, sharp bituberculate ribs that are mostly annular or bifurcate, and may zigzag a few times between separated tubercles. Wollemann (1902, p. 95) also observed this in his Hamites wernickei when he wrote, "Die meisten Rippen verlaufen von dem Knoten der Externkante ungetheilt über die Externseite zum Knoten der anderen Externseite; in einzelnen Fällen findet eine Gabelung in der Weise statt, dass ein Knoten der einen Externkante je eine Rippe zu zwei neben einander stehenden Knoten der anderen Externkante entsendet". Tuberculation is regular, coarsens towards the curved sector of the body chamber and, in most cases, effaces during the transition to the coiled middle growth stage (Text-fig. 1A, C). Apart from one of Wollemann`s specimens (1902, pl. 5, fig. 2a; reillustrated here as Text-fig. 1A) there are no specimens which show the transition from the helically coiled middle growth stage to the merely loosely connected body chamber. At this particular point, most fragments are broken as a result of differential preservation (see Text-figs 1, 3), also observed by Wollemann (1902, figure caption of pl. 5, fig. 2a). All fragments of W1­W4 (i.e., the last four whorls) with Wh 22­54 mm have simple, mostly nontuberculate primaries (Table 1). Specimen BGR X 13000 bears 1­2 collared constrictions per whorl between Wh 33­42 mm. Whorls of the early growth stage are helicoidal up to a minimum Wh 16 mm, are mostly bituberculate, but, in a few cases, can also be nontuberculate (Text-figs 5D, 6B). Low Wb/Wh ratios of the middle growth stage, developed in specimen SH 42 (Text-fig. 7), seem to be of primary nature and not the result of compaction. DISCUSSION: Nostoceras (Didymoceras) wernickei ranks among the larger European nostoceratid ammonites with U-shaped body chambers attaining up to 285 mm, and is comparable in this respect to Nostoceras (Didymoceras) postremum (Blaszkiewicz, 1980) from the Lehrte West Syncline, c. 100 km south of Lüneburg, which has a loosely connected C-shaped body chamber up to 300 mm (Niebuhr 2004; see Text-fig. 4A­B here). Both N. (D.) wernickei from Lüneburg and N. (D.) postremum from the Lehrte West Syncline are defined by their distinct body chambers. In N. (D.) wernickei coiling in the middle growth stage is helicoidal with whorls not touching or barely so, and the early growth stage is regular openly coiled. However, helicoidal whorls of the middle growth stage between Wh 22­54 mm are not diagnostic and show considerable similarities, both in dimensions and ornament, to mostly nontuberculate Nostoceras (Bostrychoceras) polyplocum (Roemer, 1841) (see in particular Kennedy and Kaplan 1997, p. 52, pl. 39, fig. 4; pl. 41, figs 1, 9; pl. 43, figs 1, 4­5; pls 44, 46). The last three whorls (W1­W3) of MMG NsK 3 (Text-fig. 6D) are comparable with the bituberculate last whorl of the adult macroconch of N. (B.) polyplocum of Kennedy and Kaplan (1997, pl. 48); however, W3 displays a collared constriction in the present individual. Similarly, bituberculate whorls of the early growth stage of N. (D.) wernickei of a Wh smaller than 22 mm (e.g., BGR MA 14523; see Text-fig. 5D) are quite similar to N. (B.) polyplocum of Kennedy and Kaplan (1997, pl. 40, figs 1­4, 6­7; pl. 42, figs 1, 3­5, 7; pl. 43, figs 2, 3), which was subsequently referred to as Nostoceras (Didymoceras) sp. 1 by Küchler and Odin (2001). It is not possible to assign isolated fragments of helicoidal whorls of the middle and early growth stages between Wh 9­54 mm to one of these nostoceratid taxa. Nostoceras (Bostrychoceras) polyplocum Stemwede 1 and Hannover 2, Germany body chamber maximum vL Wh Rr Ri shape tuberculation constrictions ribs 150 mm 38­65 mm 6.3 7­8 irregular, short hook 2 ventral rows, irregular apertural dense simple primaries, identical to helicoidal part 140 mm 42­64 mm 4.5 10 medium C-shaped 2 ventral rows, irregular apertural simple primaries, similar to helicoidal part 300 mm 40­70 mm 4.5­11.5 6­11 medium to large C-shaped 2 ventral rows, irregular apertural macroconchs: distant coarse primaries, few bifurcations microconchs: simple primaries, similar to helicoidal part 285 mm 32­45 mm 7.7­9.5 5­9 large U-shaped Nostoceras (Didymoceras) postremum, holotype Vistula River Valley, Poland 3 Nostoceras (Didymoceras) postremum Hannover, Germany 2 Nostoceras (Didymoceras) wernickei Lüneburg, Germany 4 2 ventral rows, regular none distant coarse primaries, few bifurcations helicoidal part Wh Wb/Wh Rr Ri coiling tuberculation constrictions ribs W5­W1 = 10­56 mm 0.54­1 2.7­3.3 11­13 early: loosely, mid: close early: bituberculate, mid: mostly nontuberculate few dense simple primaries, few bifurcations W1 = 42­50 mm 0.8­0.9 2.0­3.1 10­13 loosely mid: uni- to bituberculate, very weak none dense simple primaries, few bifurcations W4­W1 = 27­50 mm 0.5­0.72 4.8 6­11 loosely early: bituberculate, mid: nontuberculate none dense simple primaries W6­W1 = 9­54 mm 0.5­1 1.2­4.5 11­19 loosely early: bituberculate, mid: nontuberculate none, or 1­3 per whorl dense simple primaries Table 2. Comparison of Nostoceras (Bostrychoceras) polyplocum, N. (Didymoceras) postremum and N. (Didymoceras) wernickei from Germany and Poland; according to 1 Kennedy and Kaplan (1997), 2 Niebuhr (2004), 3 Blaszkiewicz (1980), 4 the present paper At Lüneburg, helicoidal parts of up to four whorls are associated exclusively with distinct, only loosely connected U-shaped body chambers of N. (D.) wernickei. The very short body chamber of N. (B.) polyplocum is closely associated with the last phragmocone whorl and therefore often preserved attached in large suites from the "Haldemer Schichten" at Stemweder Berg (Kennedy and Kaplan 1997), the Lehrte West Syncline near Hannover (Küchler and Schneider 2013) and Tercis les Bains, southwest France (Küchler and Odin 2001). However, polyplocum-like body chambers are unknown from Lüneburg, and therefore, it is assumed that contemporary nostoceratid helicoid whorls are conspecific with N. (D.) wernickei. Nostoceratid heteromorphs develop a change of approximately 90 degrees in their direction of growth in transition from the septate helicoidal whorls to the hook. As defined for Nostoceras (Didymoceras) (see Wright et al. 1996, p. L247) the middle and final portions of body chambers have their characteristic two rows of tubercles in a ventral position. In the older portion of body chambers (transitional part; see Text-figs 1­4), venter and tuberculation shift to the external side of the whorl. In the Lüneburg material, this phenomenon was referred to as "twisted whorls" ["verdrehte Windungen"] by Wollemann (1902, p. 95) and "torsion of the body chamber" ["Torsion der Wohnkammer"] by Wiedmann (1962, p. 209). Associated are irregularities in ribbing and tuberculation, i.e., bifurcation of ribs ["Gabelung" of Wollemann 1902, p. 95]. These features are lacking in the "species" wernickei of the genera Hamites, Anisoceras, Neancyloceras and Pseudoxybeloceras to which the authors listed above referred the material. The transitional part with torsion clearly Text-fig. 3. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) from the Zeltberg Quarry at Lüneburg, northern Germany. A ­ BGR MA 14515; U-shaped body chamber with transitional part, bituberculate and with delicate, regular ribbing. B­C ­ BGR MA 14514, neotype; U-shaped body chamber with adult aperture and beginning of transitional part, bituberculate and of delicate, regular ribbing, and ventral view of the curved portion of the body chamber, respectively. All specimens are natural size Text-fig. 4. Reillustration of Nostoceras (Didymoceras) postremum (Blaszkiewicz, 1980) from the Lehrte West Syncline near Hannover (Niebuhr 2004, pl. 1). BGR MA 13592; A ­ lateral view; B ­ ventral view of a complete, C-shaped body chamber with adult aperture, transitional part with bifurcation of ribs as well as younger portions of the last whorl; largest known specimen (D = 200 mm), bituberculate and with delicate, regular ribbing; note break between body chamber and helicoidal part. Both views are × 0.75 demonstrates that wernickei belongs to the Nostoceratidae. However, large bituberculate, U-shaped body chamber fragments without torsion, as illustrated by Pervinquière (1907, pl. 3, fig. 33), Naidin in Krymgolts (1974, pl. 57, fig. 3) and Kennedy and Summesberger (1984, pl. 10, fig. 1 only) look quite similar and are barely distinguishable from the middle and final portions of nostoceratid body chambers. The localities from which the authors listed above recorded their material also yielded other nostoceratid taxa [in part associated with typical N. (B.) polyplocum; see, in particular, Kennedy and Summesberger 1984, pl. 9, figs 4, Text-fig. 5. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) from the Zeltberg Quarry at Lüneburg, northern Germany; helicoidal parts. A ­ BGR X 13000; three nontuberculate whorls (W1­W3) of the loosely coiled middle growth stage, five collared constrictions visible. B­C ­ BGR X 13002; nontuberculate whorl of the middle growth stage, in lateral and top views, respectively. D ­ BGR MA 14517; nontuberculate last whorl (W1) and fragment of W2 of the middle growth stage. E ­ BGR MA 14523; bituberculate whorl of the loosely coiled early growth stage; septum visible. All specimens are natural size 8, 13­14] and several other index ammonites of late late Campanian age. Therefore, it is most likely that N. (D.) wernickei also appears in Upper Austria, Tunisia and the Donbass region. Furthermore, Mikhailov (1951, pl. 1, fig. 1 = ?), Wiedmann (1962, pl. 12, fig. 5 = ?), Klinger (1976, pl. 33, fig. 4 = ?), Kennedy and Summesberger [1984, pl. 6, fig. 3 = Lewyites elegans (Moberg, 1885); pl. 9, figs 6­7 = Oxybeloceras aff. crassum (Whitfield, 1877); pl. 10, figs 8­9 = ?] and Kaplan et al. (1996, pl. 35, figs 6­7 = ?) figured at least five different polyptychoceratines under the species name wernickei. Although Wollemann (1902) assigned his material to the genus Hamites, he discussed at length similarities to Heteroceras polyplocum, as follows, "Einzelne zusammengedrückte und verdrehte Windungen der mit Knoten versehenen Form des Heteroceras polyplocum sind unserem Hamiten bisweilen sehr ähnlich" and "Einige Bruchstücke ... [of his Heteroceras polyplocum] ... haben durch Verdrückung und Verdrehung eine Hamites-artige Gestalt angenommen und wurden deshalb im Lüneburger Museum unter der Bezeichnung Hamites und Helicoceras aufbewahrt" (Wollemann 1902, pp. 95, 97). However, all subsequent authors adopted Wollemann's (1902) first familial assignment. Consequently, the specific name wernickei is no longer available for Polyptychoceratinae. The present U-shaped body chambers of N. (D.) wernickei are similar to hooks of Didymoceras cheyennense (Meek and Hayden, 1856) from the Western Interior of the United States (see Kennedy et al. 2000). However, in that species shafts are shorter, the youngest Text-fig. 6. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) from the Zeltberg Quarry at Lüneburg, northern Germany; helicoidal parts. A ­ SM 48; half a whorl of the middle growth stage, older portion nontuberculate and younger portion bituberculate. B ­ SM 31; weakly bituberculate whorl of the loosely coiled early growth stage. C ­ SM 49; two nontuberculate whorls (W2­W3) of the middle growth stage, more tightly coiled, septa visible; note that both sides of W3 are broken. D ­ MMG NsK 3; four whorls (W1­W4) of the middle growth stage, more tightly coiled, W1 and W2 bituberculate, W3 and W4 nontuberculate but with collared constrictions. All specimens are natural size parts with adult aperture are approximated so that the opening between shafts is oval rather than U-shaped. Furthermore, the early and middle growth stages are utterly different, both in coiling and ornament. We also note that the helicoidal parts of N. (D.) wernickei differ from those of most species of Didymoceras in comprising more whorls in the middle growth stage (W1­W4), and in the successive part of the early growth stage (W5­W6) Text-fig. 7. Nostoceras (Didymoceras) wernickei (Wollemann, 1902) from the Zeltberg Quarry at Lüneburg, northern Germany. SM 42; recently in the exibition of the Museum Lüneburg; largest helicoidal portion known, consisting of four mostly nontuberculate whorls (W1­W4) of the loosely coiled middle growth stage, W3 having a few weak tubercles of the lower row. Natural size whorls are regularly openly coiled. For that reason, we consider N. (D.) wernickei to be a discrete species. STRATIGRAPHY AND DISTRIBUTION: In addition to the occurrence at Lüneburg (bipunctatum/roemeri Zone; upper upper Campanian), N. (D.) wernickei probably appears in the upper Campanian of the Gschliefgraben (Upper Austria), Tunisia and the Donbass region. terruptum (Schlüter); Küchler, pl. 12, figs 9, 10 only [non pl. 12, figs 4­8 = Polyptychoceratinae sp. indet.]. 2001. Oxybeloceras sp.; Kennedy and Odin, p. 481, pl. 2, fig. 17. 2006. Oxybeloceras aff. crassum (Whitfield, 1877); Jagt and Neumann, p. 567, fig. 1A­C. 2013. Oxybeloceras aff. crassum (Whitfield, 1877); Jagt, p. 138, fig. 1. Family Diplomoceratidae Spath, 1926 Subfamily Polyptychoceratinae Matsumoto, 1938 Genus Oxybeloceras Hyatt, 1900 TYPE SPECIES: Ptychoceras crassus Whitfield, 1877, by original designation. DIAGNOSIS: Two straight shafts in hairpin-like, tight contact except for tear-shaped, narrow opening at the elbow linking shafts; narrow, sharp ribs bear two rows of small ventral tubercles; constrictions lacking. REMARKS: Wright et al. (1996, p. L255) regarded Oxybeloceras as a synonym of Solenoceras Conrad, 1860; however, this view is not adopted here. MATERIAL: The original of Wollemann (1902, pl. 4, fig. 5), in the BGR Berlin-Spandau collection (BGR X 5873), of which MMG NsK 4 and NHMM 2015 019 are plaster casts. The specimen comes from the Zeltberg Quarry at Lüneburg, Niedersachsen, northern Germany, from the "blauer Mergel" (as noted on the associated label) of the "Heteroceras-Schicht des MucronatenSenons", i.e., upper upper Campanian (bipunctatum/roemeri Zone). DESCRIPTION: The single specimen from Lüneburg (Text-fig. 8A­B), preserved as a composite mould, attains an overall length of 45 mm and consists of two straight, parallel limbs in close approximation, both limbs preserved for equal lengths and Wh c. 7 mm. The curved sector, with an elbow diameter of 14.2 mm, is associated with a small, elongate, teardrop-shaped opening; early whorls and aperture are missing. The ornament consists of strong, straight ribs, Ri = 3.5­4; ?each rib (probably due to poor preservation; compare Wollemann 1902, p. 95) has a weak, inconspicuous bullate ventrolateral tubercle. Ribs are straight and prorsiradiate on the smaller limb, rectiradiate on the curved sector and rursiradiate and more widely spaced on the larger limb, weakening on the venter. No constrictions or sutures seen. DISCUSSION: Two straight, hairpin-like, closely adpressed shafts and a tear-shaped opening associated with the curved sector are characteristic of the genus Oxybeloceras and differentiate it from Pseudoxybeloceras (Parasolenoceras). In addition, species of Solenoceras are similar, albeit often bear constrictions. Oxybeloceras aff. crassum is not common in northern Germany. To date merely a handful of specimens are known (Wollemann 1902; Jagt and Neumann 2006; Jagt 2013). The three specimens from the Lehrte West Syncline near Hannover (one of which is refigured here in Text-fig. 8C), are closely comparable in size and general habitus to Wollemann's individual, with overall lengths of 38.5 mm, 85.5 mm and 56 mm, elbow diameters of 15.5 mm, 18 mm and 10 mm and Ri = c. 4). Jagt and Neumann (2006) and Jagt (2013) discussed at Oxybeloceras aff. crassum (Whitfield, 1877) (Text-fig. 8) pars * 1902. Hamites Wernickei Wollemann, p. 95, pl. 4, fig. 5 only [non pl. 4, fig. 4; pl. 5, figs 1, 2 = Nostoceras (Didymoceras) wernickei (Wollemann, 1902)]. 1976. Solenoceras wernickei (Wollemann, 1902); Klinger, p. 73. non 1976. Neancyloceras sp. cf. Neancyloceras wernickei (Wollemann), 1902; Klinger, p. 73, pl. 33, fig. 4; text-figs 8i, 10f (= Polyptychoceratinae sp. indet.). pars 1984. Pseudoxybeloceras (Parasolenoceras) wernickei (Wollemann, 1902); Kennedy and Summesberger, p. 166, pl. 9, figs 6, 7 only [non pl. 6, fig. 3 = Lewyites elegans (Moberg, 1885); pl. 10, fig. 1 = ?Nostoceras (Didymoceras) wernickei (Wollemann, 1902); pl. 10, figs 8, 9 = Polyptychoceratinae sp. indet.]. 1984. Pseudoxybeloceras (Parasolenoceras) interruptum (Schlüter, 1872); Kennedy and Summesberger, p. 167, pl. 6, figs 5, 10, 11. 2000. Pseudoxybeloceras (Parasolenoceras) ?wernickei (Wollemann); Küchler, pl. 12, figs 1­3. pars 2000. Pseudoxybeloceras (Parasolenoceras) cf. in- Text-fig. 8. Oxybeloceras aff. crassum (Whitfield, 1877). A ­ Reillustration of Hamites wernickei of Wollemann (1902, pl. 4, fig. 5) from the Zeltberg Quarry at Lüneburg, northern Germany; natural size. B ­ BGR X 5873, holotype, the original of Wollemann (1902, pl. 4, fig. 5); two parallel shafts of equal length and whorl height and the connecting curved sector (note subsequent damage to the latter); natural size. C ­ Reillustration of Oxybeloceras aff. crassum (Whitfield, 1877) of Jagt (2013, fig. 1) from the Lehrte West Syncline near Hannover, minor/polyplocum Zone (C. Holschemacher Collection, Berlin); two parallel shafts of unequal length and whorl height and the connecting curved sector; × 1.5 length the affinities to the North American species Oxybeloceras crassum (Whitfield, 1877) and Spiroxybeloceras kimbroense Kennedy and Cobban, 1999, which both are close in style of ribbing, rib index and general habitus. Jagt and Neumann (2006) remarked that the limited material from the Lehrte West Syncline near Hannover (MAB 3290a­b; C. Holschemacher Collection, Berlin) appeared to have less closely spaced ribbing on the smaller limb and a less regular occurrence of ventrolateral tubercles. Material from other European countries (see below) also is rare and of mediocre preservation, but it would appear that the size of the teardrop-shaped opening is similar to that in specimens of O. crassum from the upper Campanian of Montana, Wyoming and Colorado, and rib density overlaps. For now, we prefer to keep this form in open nomenclature until better-preserved material becomes available. STRATIGRAPHY AND DISTRIBUTION: Apart from the Lüneburg specimen from the bipunctatum/roemeri Zone (upper upper Campanian), O. aff. crassum is known from the uppermost lower to lowermost lower upper Campanian (upper vulgaris/stolleyi to minor/polyplocum zones) of the Lehrte West Syncline near Hannover, northern Germany; the lower upper Campanian (Pseudoxybeloceras Zone) of Tercis les Bains, southwest France; the upper upper Campanian (polyplocum to pulcherrimus zones) of Navarra, northern Spain, and the upper Campanian of the Gschliefgraben, Upper Austria. CONCLUSIONS In view of the fact that the species name wernickei (of Wollemann 1902) is here restricted to three (out of four) of the originally illustrated late late Campanian (bipunctatum/roemeri Zone) heteromorphs from the Zeltberg Quarry (Lüneburg, northern Germany) that have irregularities of ribbing and tuberculation and a change in direction of growth at the transition from the helicoidal whorls to the hook, the single hairpin-shaped diplomoceratid (polyptychoceratine) specimen is in need of a new name. The former are assigned to the subfamily Nostoceratinae as Nostoceras (Didymoceras) wernickei (Wollemann, 1902) comb. nov., while the latter is referred to as Oxybeloceras aff. crassum (Whitfield, 1877). Comparison with previous records of heteromorph taxa under the name of wernickei demonstrates that the geographic range of N. (D.) wernickei probably also included Upper Austria (Gschliefgraben), Tunisia and the Donbass region; O. aff. crassum is known from the Hannover area (northern Germany), southeast France, northern Spain and Upper Austria (Gschliefgraben). Acknowledgements We wish to thank to J. Erbacher (BRG, Hannover) and A. Ehling (BGR, Berlin-Spandau) for access to material in their care, to D. Schumacher (Lüneburg) for donating his specimens from the Zeltberg Quarry at Lüneburg and for assisting with field work, images and measurements, to C. Holschemacher (Berlin) for making material from the Hannover area available for study, and to M. Röthel and R. Winkler (SNSD) for preparatory and photographic assistance. W.J. Kennedy (Oxford, U.K.) and H.C. Klinger (Cape Town, South Africa) are thanked for constructive comments on an earlier typescript.

Journal

Acta Geologica Polonicade Gruyter

Published: Dec 1, 2016

References