First Sauropterygian Remains from the Upper Muschelkalk (Middel Triassic) of the Wesergebirge in NW-Germany
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PHILIPPIA 11/2 S. 151-165 8 Figs. Kassel 2003 Cajus Diedrich, Markus Plesker & Rainer Springhorn First Sauropterygian remains from the Upper Muschelkalk (Middel Triassic) of the Wesergebirge in NW-Germany Abstract Inhalt In the Upper Muschelkalk (Ladinian) of the 1. Inroduction ...................................................... 151 Weser Mountains (NW-Germany) some rare 2. Geology ........................................................... 152 isolated bones and teeth of sauropterygians 2.1. Stratigraphy .................................................... 152 were collected. Simosaurus gaillardoti H. v. 3. Systematic description ................................... 154 MEYER 1842, Nothosaurus mirabilis MÜNSTER 4. Discussion ...................................................... 160 1834, Nothosaurus giganteus MÜNSTER 1834, Acknowledgments........................................... 163 Placodus gigas AGASSIZ 1834, and Neustico- References...................................................... 163 saurus sp. are represented. The sauroptery- gian remains occur in different facies types indicating different taphonomic processes or 1. Introduction biotopes of the marine reptiles. A first monograph of saurian remains of the Germanic Triassic was published by MEYER (1847-55). Many descriptions of new sauro- Zusammenfassung pterygians were published in the last century. Anhand aktueller Funde werden seltene After a revision of these early sauropterygian isolierte Knochen- und Zahnrelikte von findings (cf. RIEPPEL 1993, 1994a, b, 2001, Sauropterygiern aus NW-Deutschland von RIEPPEL & WILD 1996) new prospections star- verschiedenen Fundstellen vorgestellt. Sie ted to collect new material in Israel (RIEPPEL, stammen aus dem Oberen Muschelkalk MAZIN & TCHERNOW 1999), Italy (RIEPPEL & (Ladin) des Weserberglandes. Die fünf Taxa VECCHIA 2001), Germany (DIEDRICH 1996, Simosaurus gaillardoti H. v. MEYER 1842, 1998, and this paper) and the Netherlands Nothosaurus mirabilis MÜNSTER 1834, Notho- (OOSTERINK 1986). New findings should give saurus giganteus MÜNSTER 1834 und Placo- information of systematics, biostratigraphy, dus gigas AGASSIZ 1834 sowie Neusticosau- taphonomy and palaeoecology of Middle rus sp. konnten nachgewiesen werden. Die Triassic reptiles. Sauropterygierreste treten faziesabhängig auf und deuten auf unterschiedliche taphono- Sauropterygian remains are very rare in the mische Bedingungen bzw. Lebensräume der Upper Muschelkalk of the Osnabrücker Berg- marinen Reptilien. land, Teutoburger Wald, and Weserbergland in northwest Germany. On the contrary, findings in southern Germany are more abundant and mostly enriched in widespread 152 Cajus Diedrich, Markus Plesker & Rainer Springhorn North Sea 2. Geology HAMELN The Weser Mountains are characterized by W Alverdissen e Triassic sediments of the Germanic Basin Bremen r e s s e s e r m W BAD consisting of Bunter, Muschelkalk and Keuper E Loßbruch PYRMONT Formations. The Upper Muschelkalk in this Münster W eser- region is built up of almost 60 m carbonates Te Lügde ut ob DETMOLD more or less in horizontal stratification and ur ge Vahlbruch r W show different facies-types influenced by the ald Gebirge palaeogeographical situation, such as the Heesten costal facies, the Egge Swell or the Brakel E Muschelkalk Swell (KLEINSORGE 1935, WOL- g g Eilversen e BURG 1969, EL-NOSHOKATY 1972). Sediment PADERBORN g e b HÖXTER types are dolomitic yellow limestones, biocla- i r g e stic limestones (terebratula limestone, trochi- tic limestone), ooliths, marls intercalated by Fig. 1: Geographical position of sauropterygian localities in the Weser Mountains (NW Germany). (Graphics: storm shell beds (= Tonplatten), clays and PALEOLOGIC 2003). rarely bonebeds (cf. fig. 2). 2.1. Stratigraphy bonebeds (e. g. Muschelkalk/Keuper bound- Previous research of stratigraphy (e.g. RHODE ary bonebed, MÜNSTER 1834, FRAAS 1896, 1963, LORENZ 1967, DUCHROW & GROETZ- SCHMIDT 1928, 1988, WESTPHAL 1988) or NER 1984, ROSE 1986 and others) and new bioclastic chalks like the “Bayreuther Saurier- own observations of multistratigraphy (litho- kalk” (MÜNSTER 1834, GEISSLER 1895). and biostratigraphy) are presented. The locations of our sauropterygian prospec- The Upper Muschelkalk of the Weser Moun- tions (fig. 1) are recent and old quarrys in the tains (fig. 2) is devided into the basal Teutoburger Wald and the Weserbergland mo1 comprising the Gelbe Basisschichten (Northwest-Germany). They are to be found (mo1GB), and Haupttrochitenkalk (mo1HT). on the topographical maps 1 : 25 000 with the The mo2 is devided into the Lower Tonplatten coordinates listed as following: Alverdissen (mo2C1), the Upper Trochitenkalk (mo2CT), (3920 Extertal, R 3509,20 H 5765,70); Ben- and the Upper Tonplatten (mo2C2/3) interca- trup (4019 Detmold, R 3492,50 H 5761,50); lated of the Terebratelkalk (mo2TK). Eilversen (4222 Höxter, R 3518,30 H 5741,50); Erkeln (4221 Brakel, R 3515,90 H The yellow basic dolomites are followed by the 5726,00); Heesten (4119 Horn Bad Meinberg, Haupttrochitenkalk, built of carbonate types R 3499,50 H 5748,50); Luedge (4021 Bad Pyr- like dolomite, oolithe, and trochitic limestone mont, R 3519,50 H 5756,20), and Vahlbruch depending on the palaeogeographical situa- (4022 Ottenstein, R 3525,70 H 5754,30). tion. In its upper part the mo1HT is interrupted by the Zwischenmittel developed as Tonplat- The material described in this study is stored ten facies (RHODE 1963). The Zwischenmittel in the Lippische Landesmuseum Detmold is regarded to be an isochron marker bed in (= LLM) under the numbers: mo 505-556, and the Weser Mountains. Above the mo1HT the mo 947. A list of the sauropterygian remains Lower Tonplatten (mo2C1) follow. The pelagic and some photographs are presented on the website http://www.lippisches.landesmuseum.de of the Museum. right site, fig. 2: Stratigraphy of the Upper Muschelkalk in the Weser Mountains and sauropterygian remain horizons. (Graphics: PALEOLOGIC 2003). First Sauropterygian remains from the Upper Muschelkalk of the Wesergebirge 153 Bremerberg-Bank Legend Sauropterygians claystone 100m "tonplatten" dorsoplanus- 520 bioclastic limestone Zone Rostige Bank s i Bonebed III l braciopod bioclast i Ostracina-Bank b crinoid bioclast a r nodosus- i oolith m Zone Alberti-Bank s dolomicrit u Bonebed II r praenodosus-Zone u a s o sublaevigatus- h t Zone o N enodis- mo2C3 Zone Großenberg-Bank postspinosus- Zone Ton 5 . 2 p s o K s u r L m u a s A spinosus- o c i K Zone t Ton 4 s u L e 516- N E Bonebed I 518 H Ton 3C evolutus-50m Hehlen-Bank 2 C Ton 3B Zone Ton 3A S Hehlen-Bank 1 U mo2TK Terebratelkalk s M compressus- u e Zone t r n Ton 2 a g e i g p s u r p s mo2C2 robustus- u a a g Zone s i U Ton 1 o g h t s o u d N 505 o c a l Ceratitenschichten P pulcher- 513, mo2CT in trochitic limestone 514 Zone facies i t Coenothyris-Bank o d r a mo2C1 Lower Tonplatten l l i a g Zwischenmittel s 10m u atavus- r u 1 mo1HT Zone ? Haupt-Trochitenkalk a s o o m m i DIEDRICH & S mo1GB PLESKER 2000 Gelbe Basisschichten 508 154 Cajus Diedrich, Markus Plesker & Rainer Springhorn Tonplatten facies close the Teutoburg Forest brücker Bergland (DUCHROW & GROETZNER is almost interrupted by a second trochitic 1984) or southern Germany (HAGDORN 1991). limestone facies, starting basally with a bra- The few bonebeds I-II contain small vertebrate chiopod dominated Coenothyris-Bank (Upper bones like fish scales, fish and selachian Trochitenkalk, LORENZ 1967). Where this Tro- teeth, almost sorted in size. One of these chitenkalk (mo2CT) is missing, it is replaced widespread bonebeds is the base of the by a brachiopod bed and some Encrinus beds Bonebed I. Another characteristic bonebed is (RHODE 1963, LORENZ 1967). In most quar- developed at the base of the Alberti Bank. The ries the stratigraphic position of the Trochiten- Bremerberg Bank seems to correlate with the kalk (mo2ß/mo2CT) is in the pulcher Zone. “Grenzbonebed” of South Germany. These bonebeds do not contain a rich amount of Sau- Along the Teutoburg forest and close to the ropterygian remains like the Grenz-Bonebed Brakel Muschelkalk Swell there is a Terebra- of the Upper Muschelkalk/Lower Keuper telkalk developed between the compressus- boundary in South Germany (e. g. Crailsheim, and the evolutus-Zone of the mo2 (mo2TK, Bayreuth, cf. e. g. SCHMIDT 1928, 1988, DUCHROW & GROETZNER 1984). The percen- HAGDORN 1991). tage of trochites in this facies type increases regionally. In this case it appears as another The fossiliferous horizons of the described trochitic limestone facies (Upper Trochiten- sauropterygian remains are marked in the kalk, KLEINSORGE 1935). In the quarry of Ben- generalized section except for those that were trup/Loßbruch (Gretberg), it becomes evident not found on a dump. that the mo2TK is an additional development to the mo2CT, although is was regarded to be identical with the mo2CT by NOLTE (1982). 3. Systematic description In the Weser Mountains the Ceratitenschich- The material consists of isolated bones and ten/Tonplattenfolge (mo2alpha/mo2C1) is al- teeth of sauropterygians. Isolated bones were most starting in the pulcher Zone, reaching up found in concretions or bonebeds, teeth of into the dorsoplanus Zone, intercalated bet- Placodus in shill beds (bioclastic limestones ween the ostracina-Bank and the Bremerberg like crinoid limestone or molluscan shell lime- Bank. The youngest ceratite to be found stone). Two incomplete ribs, three vertebral is Ceratites (Discoceratites) dorsoplanus centra, one vertebra, and some teeth could PHILIPPI, found 1.3