J. mic~ropulueontol.,9 (2): 253-256, March 1991
The Foraminiferid Osangulariu schloenbachi (Reuss, 1863); the erection of a neotype.
STEPHEN CRITTENDEN’ AND ROGER J.PRICE2 1. Geolink (UK) Ltd., Silverburn Crescent, Bridge of Don, Aberdeen AB2 8EW. 2. Ammo Canada Petroleum Co Ltd., PO Box 200, Station M, Calgary, Alberta, 2TP 2H8, Canada.
ABSTRACT -The benthonic foraminiferid Osangularia schloenhachi (Reuss, 1863) is an established index taxon for Albian to Aptian age sediments worldwide. It is a very useful marker species commonly encountered in cuttings sampled from offshore boreholes on the north-west European continental shelf. However, despite its biostratigraphical utility there is no known holotype for this species. This short article rectifies this taxonomic point of order by erecting a neotype for the species.
INTRODUCTION The neotype is not therefore designated as an end in itself, The foraminiferid described by Reuss (1863) as Rotalia nor even as a matter of curatorial routine but because it is schloenbac*hi from the “mittleren Minimustohn von needed as a result of the biostratigraphical utility of the species Rohrenstollen aus einem Rohrengraben im nordwestlichen in strata of Early Cretaceous age. Theile des Sommerholzes bei Kniestedt” is not represented by In addition, the neotype for 0.schloenhachi is erected as an a designated holotype in any known repository. Reuss in his adjunct to the revisory taxonomic work of Crittenden (1983). publication did not designate a holotype or indicate the wherea- The erection of a neotype is an essential procedure vital for bouts of his collected and described material ( 1863). In addition solving taxonomical problems associated with confused and Reuss neglected to provide accurate details of the stratigraphical doubtful identities of closely similar species of foraminifera horizon, section studied and the exact geographical location of (e.g. Edwards, 1981). the original sample. This imprecision is a result of a sampling In the erection of a neotype a number of qualifying condi- technique popular among 19th century micropalaeontologists; tions, in addition to those discussed in the previous paragraphs, often they did not collect their own samples but relied upon havetobesatisfied(ICZN, 1985).Theseconditionsarediscussed collectors/friends/acquaintancesto supply them with samples and satisfied in turn as follows; for study. The mud samples studied by Reuss forhis 1863paper 1. The species for which the neotype is erected/designated can were provided by his good friend, Mr A. Schloenbach, a be differentiated from other taxa by a number of characters. saltworks inspector from Liebenhalle near Saltzgitter.No doubt A full description of Osangularia schloenbachi is given by during the course of his employment Mr Schloenbach had Crittenden (1983) where the character variation of the ample opportunity to obtain samples from boreholes and quar- species is discussed. ries in the Salzgitter Bad area where Kniestedt is located. 2. The neotype designated is identified by the British Museum The situation is remedied herein by erecting a neotype for (Natural History)catalogue number P52254 and has the the stratigraphically important foraminiferid Osangularia following dimensions: maximum diameter, 0.405mm; 10- schloenhuchi (Reuss, 1863). 11 chambers in the final whorl. Reuss’s (1 863) illustrated specimen has a maximum diameter of 0.42mm and has 10- QUALIFICATION 11 chambers in the final whorl. The foraminiferid described as Rotalia schloenbachi by Reuss 3. No previous valid holotype or neotype for the species has (I 863) has been discussed both by Price (1 976) and Crittenden been designated. (1983). The latter author regards it as the type species for 4. The neotype designated in this article is consistent with Osangular-ia schloenbachi (Reuss). The revisory work of what is known of the species described by Reuss (I 863) Crittenden (1983) comprises a critical study of the species despite the relatively poor illustration of Reuss (I 863) taxonomy and a discussion of its stratigraphical importance in which is reproduced here as Plate I, Figs 8- 10. strata of Albian and Aptian age. As a consequence of the 5. The original type locality of Reuss’s material is not desig- stratigraphical importance of Osangularia schloenbachi it is nated and it is therefore impossible to collect the neotype desirable that a neotype is erected. from the exact same geological horizon (topotype). How-
253 Neotype of Osangular-ia schloenbachi
ever, the neotype collected in this study comes from the (Kemper, pen.comrn.). The complete absence of foraminifera same geographical area and the same geological formation in the washed sample residues, comprising abundant quartz, - “Gault Clay/Minimustohn” as the specimens of Reuss glauconite and iron oxide, of the basal part of the section does ( 1863). The neotype locality therefore becomes the type not permit biostratigraphical age dating. locality . The upper part of the section, dated by Spaeth as E. lautus As original material from Reuss’s samples or slides is not Biozone age, contains an abundant foraminiferal fauna which available and as the original sample collection location is substantiates the age assignment (foraminiferal fauna Biozone not known no paratypes or topotypes are available from 4 of Price, 1977, see figs 3 & 4 and table 1). which a neotype can be selected. The neotype designated in this article is deposited in the ACKNOWLEDGEMENTS British Museum (Natural History) which is an accepted The authors wish to thank Dr Alan R. Lord of University repository for scientific material. College London for photographing (Scanning electron micro- graph) the neotype of 0. schloenbachi. In addition we wish to NEOTYPE DESIGNATION thank Professor Malcolm B. Hart of Polytechnic South West Kniestadt is in the Salzgitter Bad area of the Lower Saxony for his comments and suggestions. Basin. Samples collected by Price (1975) in the area yielded a Manuscript received December 1989 foraminiferal species since identified as 0.schloerzhachi (Reuss, Revised manuscript accepted September 1990 1863): see Crittenden, 1983. The samples are from the Gault Clay of a disused quarry between Finkenkuhle and Salzgitter REFERENCES Bad and is of Euhoplites lautus Biozonal age (nitidus - dalasi Crittenden,S. 1983. Osorigirlai~iaschloerihac~hi(Reuss, 1863):an index Subzones) of the Middle Albian. The location is illustrated by foraminiferid species from the Middle Albian to Late Aptian of the Price (1977, fig. I). southern North Sea. N.Jh. Geol. Palaont. AM.. 167(1), 40-64. Edwards, P.G. 1. The foraminiferid genus Gaivliiiella in the Specimens of 0. schloenhachi are from sample number I98 Senonian of North-west Europe. Palaror~tology,24(2), 391-416.In- 5340, from bed 12 (Price, 1975) from the disused quarry ternational Commission on Zoological Nomenclature. 1985. Inter.- between Salzgitter Bad and Finkenkuhle (1 2 kilometres south national Code ofZoological Nonieric~latrtrv,adopted by the XX Gen- west of Salzgitter: map ref. T.K. Salzgitter 3928; re 3592900, er-a1Assenibly ofthe Iriteriiatiorial Union of Biological Scierices ed 3 h 5769700, Deutsche Topographische Karte 1 :25000 Messtisch International Trust for Zoological Nomenclature in associa- Blatt). From this sample a neotype for 0. schloenbachi is tion with the British Museum (Natural History), London, University designated (Plate I, Fig.6) and is deposited in the British of California Press. xx + 1-338. Museum (Natural History) with the catalogue number P.52254. Price, R.J. 1 975. Biostmtigraphy of the Alhian foraniiriI’fera of Paratypes are illustrated in Plate I, Figs 1-2 (OSC 8101), Plate iior-th-west Eitrwpe. Ph.D. thesis. unpublished, University College, London. I, Fig.3 (OSC 8 104) and Plate I, Figs 4 & 5 (OSC 8 102) and are Price, R.J. 1976. Palaeoenvironmental interpretations in the deposited in the collection of Stephen Crittenden. Albian of western and southern Europe, as shown by the distribution For comparative purposes one other specimen of 0. of selected foraminifera.First Interr~atioiiolSyniposiitni oii Beiith~iiic schloenbachi is illustrated (Plate I, Fig.7; P5 12 13, from For.aniiriI’fera of Contirieiital Margins. Part B: P alaeoecology and Crittenden, 1983, p1.5, fig.14) together with a copy of the Biostrati,~i.a/)hy.Maritinie Sedinients Special P rthlic~ationI ., 625-648. original drawing of Reuss ( 1863). For further illustrations and Price, R.J. 1977. The stratigraphical zonation of the Albian for a comprehensive taxonomic discussion reference should be sediments of north-west Europe as based on foraminifera.P im,.Geol. made to our previous works (Price, 1975, 1976: Crittenden, AS SO^,.. 8812. 65-9I. 1983). Reuss, A.E. 1863. Die Foraminiferen des norddeutschen Hils und Gault. K.Aknd.Wiss.. Math.-Natirr... CI Sit-berg. 46(1862)/1:5-100, The designated neotype is well preserved apart from debris Wien. in the apertural face area which partially conceals theosangularid Spaeth, Chr. Untersuchungen an Belemniten des aperture. All other specimens in the sample have debris in the I97 I. Formenkreises um Neohibolires niirriniits (Miller. 1826)aus dem Mittel- apertural area. undOber-AlbNordwestdeutschlands. Beih.geol../h.lOO.I-127.pls 1- 9. ASSOCIATED FORAMINIFERAL FAUNA The quarry section, and its associated foraminiferal fauna, at Finkenkuhle has been described and illustrated by Price ( 1975, pp. 1 14- 1 15, figs. 76 & 92). The macrofaunal correlation of the section has been based largely on the occurrence of belemnites, particularly Neohihilites minimus. The basal part of the section is of E. loricatus Biozonal age (Spaeth, 197 1) and possibly of intermedius sub-zonal age
254 Crittenden and Price
Explanation of Plate 1 Osun~quluriuschloiwhuchi Figs I & 2. Ventral & Edge view. Sample No.5340. Specimen No. OSC8lOl x 95. Fig. 3. Dorsal view. Sample No. 5340. Specimen No. OSC 8104 x 95. Figs 4 & 5. Ventral and Edge view. Sample No. 5340. Specimen No. OSC 8102 x 95. Fig. 6. Ventral view. NEOTYPE. Sample No. 5340. Specimen No. P52254 x 95. Fig. 7. Ventral view. Borehole 49/24-4 (4880 ft). Specimen No. P51213. From Crittenden, 1983 (plate 5, fig.14) x 95. Figs X, 9, 10. Ro/u/iu si~hloiwhai~hiReuss, 1863; from the original illustration of Reuss, pl. 10, fig.5 x 60.
255