Fusiteuthis

Christensen, Walter Kegel, 2002, Fusiteuthis polonica, a rare and unusual belemnite from the Maastrichtian, Acta Palaeontologica Polonica 47 (4), pp. 679-683 : 680-681

Distribution of Fusiteuthis

The holotype of F. polonica came from a greensand with phosphorites in the Bochotnica quarry. The greensand is sandwiched between the so−called Kazimierz Opoka of late Late, but not latest, Maastrichtian age and marly gaizes with limestone intercalations of Danian age ( Machalski and Walaszczyk 1987, 1988; Hansen et al. 1989; Machalski 1996, 1998). The base of the greensand rests upon the

L, length of guard; LAP, length from apex to protoconch; D, depth of alveolus; DVDAE, dorsoventral diameter at alveolar end; LDAE, lateral diameter at alveolar end; DVDP, dorsoventral diameter at protoconch; LDP, lateral diameter at protoconch; MLD, maximum lateral diameter; MDVD, maximum dorsoventral diameter; LVF, length of ventral fissure; RQ, Riedel Quotient (L/D); RI, Riedel Index (D×100/L); SQ, Slenderness Quotient (L/DVDAE); BI, Birkelund Index (LAP/DVDP). Measurements marked * are obtained from the figures of Kongiel (1962: pl. 1: 1–3) and quotients marked ** are based on these measurements.

strongly burrowed top of the Opoka, which is a Polish term for siliceous limestone.

The age of the greensand has been the subject of much discussion previously (see review by Machalski 1998), and it has been placed either in the uppermost Maastrichtian or in the Danian. Some authors have placed the Cretaceous–Palaeogene boundary in the middle of the greensand ( Machalski and Walaszczyk 1987, 1988).

Machalski (1998) considered the greensand as a transgressive horizon of Danian age, that contains both indigenous and reworked Danian fossils, as well as reworked Maastrichtian fossils. Reworked Maastrichtian fossils include specimens of the Upper Maastrichtian belemnitellid Belemnella kazimiroviensis (Skołozdrówna) andtheMaastrichtianammonite Hoploscaphites constrictus (Sowerby) ( Machalski and Walaszczyk 1988) , as well as the holotype of F. polonica . Machalski and Walaszczyk (1988) recorded B. kazimiroviensis from throughout the greensand and two specimens of H. constrictus from phosphatized nodules in the upper part of the greensand.

Machalski (1998) suggested that the reworked Maastrichtian fossils from the greensand may have come from two sources: 1) the top of the Kazimierz Opoka, which is of late Late, but not latest, Maastrichtian age (see below), or 2) a glauconitic chalk unit of late Late, possibly latest, Maastrichtian age, which was removed by erosion during the early Danian. Machalski (1996) placed the upper part of the Opoka ofBochotnicaquarryintheupperUpperMaastrichtian Belemnella kazimiroviensis Zone of the northwest European belem− Maastrichtian, uppermost part of the Belemnella lanceolata Zone (see below).

In conclusion, the genus was very rare but had a wide palaeogeographical range, extending from northwest Germany, across Poland to Crimea, and it has been recorded only from the basal and uppermost Maastrichtian. The Maastrichtian Stage lasted about 6 myr ( Obradovich 1994) and the longevity of the genus, therefore, was a little less than 6 myr. On the basis of the geographical and stratigraphical distribution of Fusiteuthis it may be suggested that the few specimens recorded so far were occasional migrants from an unknown area.

nite zonal scale ( Fig. 3 ). Moreover, he showed on ammonite evidencethatthispartoftheOpokaequateswiththelowerpart ofthe B. kazimiroviensis ZoneofDenmark.Thus ,itseemsthat the holotype of F. polonica came from the upper Upper, possibly uppermost, Maastrichtian.

Naidin (1973, 1975; Fig. 2 ) recorded two specimens of Fusiteuthis sp. from the uppermost Maastrichtian of Crimea, but he did neither describe nor figure these specimens. The specimen of F. polonica described here came from the basal

Figures

Fig. 3. Stratigraphical diagram, showing the range of Fusiteuthis Kongiel on the north European belemnite zonal scale. This scale was critically assessed by Christensen (1996), who noted that the Early Maastrichtian Belemnella zones are either interval or total range zones. Moreover, he showed that the base of the B. kazimiroviensis Zone is highly diachronous and becomes progressively younger from the eastern part of the Russian Platform in the east to the Netherlands in the west.The zone is Late Maastrichtian in the east, late Late Maastrichtian in Denmark and latest Maastrichtian in the Netherlands.

Fig. 2. Fusiteuthis polonica Kongiel, 1962. A. Holotype MZ VIII Med 162 in dorsal (A1), lateral (A2), ventral (A3) views, and view of the ventral anterior end of the guard, showing the ventral fissure (A4), approximately × 5. B. MGUH 26406, “Saturn” chalk pit at Kronsmoor, uppermost part of the Belemnella lanceolata Zone, ca. 3.5 m below marker horizon G 610 in dorsal (B1), lateral (B2), ventral (B3) views, and view of the ventral anterior end of the guard, showing the ventral fissure (B4), × 4. MGUH 26406 is registered in the Type Collection of the GeologicalMuseum,UniversityofCopenhagen.Allfiguresarecoatedwith ammonium chloride and are natural size unless otherwise stated.