Marine Vertebrates from the Santonian Coastal Carbonates of Northwestern Germany
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Open Geosci. 2015; 7:342–361 Research Article Open Access Cajus G. Diedrich* and Udo Scheer Marine vertebrates from the Santonian coastal carbonates of northwestern Germany – a tool for the reconstruction of a Proto- North Sea Basin intertidal dinosaur-exchange bridge DOI 10.1515/geo-2015-0020 coastal and intertidal environments; upwelling; subma- Received December 10, 2013; accepted November 03, 2014 rine swell; northwestern Germany; southern Proto- North Sea Basin; Europe Abstract: A diverse vertebrate fauna, dominated by shark teeth, is recorded from conglomerates within the lime- stones of the Upper Cretaceous (Santonian) Burgstein- furt Formation of northwestern Germany. The conglomer- 1 Introduction ate beds comprise carbonatic, glauconitic and phosphate nodules, as well as Triassic, Jurassic and Cretaceous extr- In northwestern Germany, Upper Cretaceous shark teeth aclasts. The Burgsteinfurt Formation conglomerates con- have been used in the past to interpret the bathymetry, tain ning-upwards parasequences 2–20 cm in thickness, salinity and temperature of the southern Proto- North interpreted as tempestite layers within a unit formed by Sea Basin of central Europe [1–5]. In addition, sharks larger-scale Milankovitch Cycles. The presence of the in- from middle Eocene transgressive gravels (shark-teeth oceramid Sphenoceramus patootensis and belemnite Go- bonebeds) in the same region of northern Germany were nioteuthis granulata indicate a late Santonian age for the also analysed to further understand the uplift of a sub- unit. The studied vertebrate fauna from the Weiner Esch marine swell, called the Northwestphalian-Lippe Swell, locality consists of 20 selachian species (14 macroselachi- which began in the early Cenomanian [6]. This study ans and 6 microselachians), a few teleosts, rare marine presents the rst tectonic signs of the uplift of this swell, mosasaur remains, and one tooth from a theropod di- based on localities near Ochtrup in the northwestern- nosaur. 95% of the vertebrates in the assemblage are de- most part of the Münsterland Cretaceous Basin, where, positionally autochthonous, with the remaining material like much of this basin, Coniacian–Santonian sediments reworked from older underlying Cenomanian–Coniacian crop out extensively ([7, 8]; Figure 1). A new map of late (lower Upper Cretaceous) limestones. On the basis of ob- Santonian palaeogeography, presented here, diers from served sedimentary structures, the scarcity of deep-sea the previous ‘fully marine, subtidal Santonian’ palaeo- selachians, and the dominance of the Mitsukurinidae geographic models of the Cretaceous Münsterland Basin (59% of the preserved shark fauna) in the fossil assem- ([7, 9–12]; Figure 1). blage, the unit is interpreted as a shallow (0–3 metres The Late Cretaceous marine vertebrate locality dis- deep), subtidal, nearshore environment, or even subaerial cussed here (Figure 1) is a small, long-abandoned quarry carbonate-sand islands, located on the southern margin located on a hill called Weiner Esch, 5 km south of of a submarine swell. The presence of a Santonian thero- Ochtrup in northwestern-most Westphalia, northwestern pod in this deposit, and other dinosaur records in north- Germany (topographical map Metelen, coordinates lati- ern Germany, together support the interpretation of a tude 25° 80’50” S and longitude 57° 84’82” E). The quarry short-lived uplift event with strong upwelling inuence for is protected by a preservation order, as well as being a nat- the Northwestphalian-Lippe submarine swell north of the ural and palaeontological monument. Rhenish Massif in the southern Proto- North Sea Basin. A Previously, only rare, badly preserved, isolated new migration model for dinosaurs moving along carbon- selachian teeth have been recorded from Weiner Esch, ate coasts or intertidal zones of shallow carbonate-sand is- lands in Central Europe is presented, which may explain the scattered distribution of dinosaur remains across Eu- *Corresponding Author: Cajus G. Diedrich: Private Research rope in the Upper Cretaceous. Institute PaleoLogic, Petra Bezruce 96, CZ-26751 Zdice, Czech Repub- lic, E-mail: [email protected] Keywords: Selachian fauna; teleosts; mosasaurs; thero- Udo Scheer: Ruhr Museum,Fritz-Schupp-Allee 15, D-45141 Essen, pod dinosaur; late Santonian (Late Cretaceous); nearshore Germany, E-mail: [email protected] © 2015 C.G. Diedrich and U. Scheer, licensee De Gruyter Open. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License. The article is published with open access at www.degruyter.com. Marine vertebrates from the Santonian coastal carbonates of northwestern Germany Ë 343 Figure 1: A: Map showing the study area within central Europe. B–C: Geographic position of the Santonian vertebrate and dinosaur bone localities of northwestern Germany discussed in this paper (Map of Münster Cretaceous Basin after [7, 11]; location of vertebrate fossil sites after: 1. Aachen: [1]; Halle- Ascheloh: [37]; Höver: [4, 55]). 344 Ë C.G. Diedrich and U. Scheer and little of this material was described in detail [7–9, 13]. Institutional abbreviations: Geomuseum of the West- This publication records a well-preserved assemblage in- phalian Wilhelms-University Münster, Germany (GPI), cluding selachians, some teleosteans, and a few reptile Ruhr Museum Essen, Germany (RE). teeth with the aim of better understanding the shark, sh, and reptile biodiversity of the upwelling-inuenced up- per Santonian shallow-marine carbonate sediments of 3 Geology the northern Münsterland Cretaceous Basin, within the southern Proto- North Sea Basin. In this contribution, the 3.1 Stratigraphy and age rst Santonian dinosaur remain from northern Germany is presented. Together with yet unpublished nds from two other southern Proto- North Sea Basin localities – Weiner In [7] described the 8.5 m section of limestone at Weiner Esch, Lingen (Lower Saxony), and a new locality (con- Esch as ‘Weiner Schichten’, a unit now included within the taining dinosaur remains and a comparable shark fauna Burgsteinfurt Formation (upper Santonian – lower Campa- to Weiner Esch) north of the Harz Mountains (Lower Sax- nian) with Weiner Esch as its stratotype [11]. Due to quarry ony), these dinosaur nds are important to the improving backlling prior to the site’s protection, only ve metres of the palaeogeographic map of Ziegler 1990 [12]. It allows of these sediments are still exposed (Figure 2). This sec- the interpretation of coastline and island positions, and tion is informally subdivided herein into ‘Lower Conglom- therefore the reconstruction of the swell’s uplift history. erate Beds’ and ‘Upper Sandy Limestone Beds’. At this locality, the Burgsteinfurt Formation discordantly over- lies the older lower Santonian Emscher Formation [8] due to a tectonic uplift that created a submarine swell (the Ochtrup Swell) as the northeastern prolongation of the 2 Material and methods Dutch High during the Santonian [8, 10]. During this time, Upper Triassic, Jurassic and Lower Cretaceous sediments A small collection of material from Weiner Esch was became inverted and eroded during an alpinotype subher- made by K. Niemeyer between 1966 and 1975, and his few cynic tectonic period (Wernigeröde Phase sensu [7]), form- selachian teeth are now deposited in the Geomuseum of ing the Northwestphalian-Lippe Swell. With its parallel the Westphalian Wilhelms-University Münster, Germany. mountain ranges – Wiehengebirge and Teutoburger Wald A further small, but important collection, including the – this former swell separates the Münsterland Basin from single fragment of a dinosaur tooth as well as the only the rest of the North German lowland. This tectonic event relict of a chimaera, was later made by E. Wijnker (Nether- explains the presence of conglomerates, extraclasts, and lands), which was donated to the Ruhr Museum (Essen, even the reworked shark teeth seen within our material Germany) and is housed together with the huge collec- (see Taphonomy section). Most vertebrate remains (95%) tion of K.-H. Hilpert. In addition to these three private seem to be autochthonous within the sediment, an inter- collections, the current authors etched three kilograms of pretation followed by other authors [7, 8], although some sediment collected from Conglomerate Bed II (Figure 2) of the selachian species from Weiner Esch noted in this with formic acid to obtain additional microselachians, pla- paper obviously originate from reworked Cenomanian– coid denticles and teleostean teeth. Of this material, small- Coniacian, or even middle Santonian layers (Table 1). A sized fossils were photographed with a REM, and larger comparable taphonomic situation is found in the Eocene teeth photographed using a binocular microscope, with all shark-gravels of the Fürstenau Formation (Lower Sax- drawings produced using a binocular mirror (Figures 3–7). ony, about 80 km northeast of Weiner Esch) of north- As the terrestrial reptile material (Figure 8) has proved im- ern Germany, which also contains reworked Cenomanian– portant for interpreting palaeogeography (Figure 9), two Turonian species [14]. more sites from northern Germany are mentioned herein, The sediments in Weiner Esch are considered late although the dinosaur material from these localities awaits Santonian in age (= krsa4; [7, 8]) based on the presence detailed investigation and is as yet unpublished. This un- of the inoceramid Sphenoceramus patootensis and cal- published material includes fossils from a site north of