German Basin Research Articles

The uniquely diverse taphonomy of the marine reptile skeletons (Sauropterygia) from the Lower Muschelkalk (Anisian) of Winterswijk, The Netherlands

Having provided dozens of articulated, and even more disarticulated skeletons of marine reptiles with varying degrees of completeness, the Middle Triassic fossil deposit of Winterswijk, The Netherlands, might be considered the richest within the entire Germanic Basin concerning associated and partially articulated remains. Aside from these remains, a high number of isolated bones are also found. Among the various marine reptile taxa, the pachypleurosaur Anarosaurus and the nothosaur Nothosaurus are the most common. The skeletons and remains show diverse disarticulation patterns. These patterns range from mostly complete articulated skeletons to clustered and isolated bones. Interestingly, a large number of isolated articulated limbs is found, a pattern which is not known from other marine localities. Although numerous reports have been made on the taxa from Winterswijk, the taphonomy of the locality still remains poorly understood. Here, a series of methods are used to describe the taphonomy of 327 marine reptile specimens from the locality of Winterswijk in a qualitative manner. Furthermore, it is tested whether biofilms such as microbial mats could have had an influence on the preferential preservation of several body regions. Upon investigation, it is concluded that the taphonomy of Winterswijk is very complex and indeed depends on various factors such as: current activity, microbial activity, and anatomical differences between taxa. Finally, a total of 12 recurring patterns were identified within the dataset, which could largely be explained by the aforementioned factors.

The Role of Surface Texture on the Corrosion Behaviour of High Alloyed Steels Exposed to Different Saline Aquifer Water Environments

Coupons of X5CrNiCuNb16-4 that may be used as injection pipe with 16% Chromium and 0.05% Carbon (1.4542, AISI 630) were exposed for 3000 h to CO2-saturated saline aquifer water similar to the conditions in the Northern German Basin at ambient pressure and 60 °C. Surface corrosion layers and pits reveal carbonate corrosion products on the surface such as FeCO3 and FeOOH as the main precipitation phases with no dependence on the original surface roughness. Corrosion rates for polished and technical surfaces were below 0.005 mm/year compared to corrosion rates of 0.035 mm/year after shot peening.

Numerical Modelling of Salt-Related Stress Decoupling in Sedimentary Basins–Motivated by Observational Data from the North German Basin

A three dimensional (3D) finite element model is used to study the conditions leading to mechanical decoupling at a salt layer and vertically varying stress fields in salt-bearing sedimentary basins. The study was inspired by observational data from northern Germany showing stress orientations varying up to 90° between the subsalt and the suprasalt layers. Parameter studies address the role of salt viscosity and salt topology on how the plate boundary forces acting at the basement level affect the stresses in the sedimentary cover above the salt layer. Modelling results indicate that mechanical decoupling occurs for dynamic salt viscosities lower than 1021 Pa·s, albeit this value depends on the assumed model parameters. In this case, two independent stress fields coexist above and below the salt layer, differing in tectonic stress regime and/or stress orientation. Thereby, stresses in the subsalt domain are dominated by the shortening applied, whereas in the suprasalt section they are controlled by the local salt topology. For a salt diapir, the orientation of the maximum horizontal stress changes from a circular pattern above to a radial pattern adjacent to the diapir. The study shows the value of geomechanical models for stress prediction in salt-bearing sedimentary basins providing a continuum mechanics–based explanation for the variable stress orientations observed.

Multidisciplinary approach to assess geothermal potential, Tønder area, North German Basin

This study demonstrates how a multidisciplinary approach can optimize reservoir characterization and thereby reduce the risk of failure for a potential geothermal development. A geological model of three Lower Triassic low-enthalpy geothermal reservoirs is presented based on available existing data, where 2D and 3D seismic surveys and five deep wells provide data for structural, petrophysical, petrographical, provenance and pore water analysis. Reservoir properties and continuity are controlled by depositional environment and are further affected by the highly saline formation brine, nitrogen gas and cementation by carbonate, anhydrite and halite. The lower Bunter sandstone forms a continuous reservoir of excellent quality, the middle Bunter sandstone constitutes a potential upside reservoir and the upper Bunter sandstone displays variable reservoir properties due to spatial variations in reservoir continuity.

Modeling fate and transport of hydraulic fracturing fluid in the presence of abandoned wells

Hydraulic fracturing in shale/tight gas reservoirs creates fracture network systems that can intersect pre-existing subsurface flow pathways, e.g. fractures, faults or abandoned wells. This way, hydraulic fracturing operations could pose environmental risks to shallow groundwater systems. This paper explores the long-term (> 30 years) flow and transport of fracturing fluids into overburden layers and groundwater aquifers through a leaky abandoned well, using the geological setting of North German Basin as a case study. A three-dimensional model consisting of 15 sedimentary layers with three hydrostratigraphic units representing the hydrocarbon reservoir, overburden, and the aquifer is built. The model considers one perforation location at the first section of the horizontal part of the well, and a discrete hydraulic fracture intersecting an abandoned well. A sensitivity analysis is carried out to quantify and understand the influence of a broad spectrum of field possibilities (reservoir properties, overburden properties, abandoned well properties and its proximity to hydraulic fractures) on the flow of fracturing fluid to shallower permeable strata. The model results suggest the spatial properties of the abandoned well as well as its distance from the hydraulic fracture are the most important factors influencing the vertical flow of fracturing fluid. It is observed that even for various field set-tings, only a limited amount of fracturing fluid can reach the aquifer in a long-term period.

The Triassic of southwestern Switzerland – Marine or non-marine, that is the question!

It is often difficult to distinguish nearshore marine from non-marine non-fossiliferous quartz-rich sandstones, and in many cases the depositional environment is disputed. Detailed facies analysis is necessary to determine the environment and, although there are no ‘smoking gun’ features to delineate them, a group of specific attributes in combination can be used to differentiate fluvial from marine deposits. Primary characteristics of fluvial deposits are: fining-upward channel-based sequences lacking marine indicators, well-developed palaeosols, and unimodal palaeocurrent distributions.The Vieux Emosson Formation, a Triassic autochthonous unit of the western Swiss Alps, is one such controversial example. It lies unconformably above crystalline basement and consists of a basal sandstone and conglomerate-dominated unit, and an upper heterolithic sequence of thin sandstones and mudstones with thin dolostone beds near the top. The formation is overlain by allochthonous younger carbonates of the Tethys Ocean. The light color of the basal unit gives the appearance of quartz-rich sandstone. In part because of this and also the overlying marine carbonates, previous workers interpreted the Vieux Emosson Formation as having been deposited in a marginal marine environment, along the southern edge of the continent and bordering Tethys. However, petrographic analysis determined that the Vieux Emosson sandstones are poorly sorted subarkoses and arkoses, and facies analysis indicated deposition in a continental fluvial-lacustrine system with a north-trending palaeoslope off the Vindelician High, towards the Germanic Basin. Deposition of the lower unit was in braided streams, supported by: high-relief basal erosional surface, immature sediment, large angular clasts, amalgamated fining-upward sequences, mottled palaeosol horizons with carbonate nodules, absence of bioturbation, and a unimodal palaeocurrent pattern. The interbedded sandstone and mudstone (proximal) and the upper mudstone and dolostone (distal) units represent deposition in a terminal splay-playa environment. Desiccation cracks, dolostone, absence of body fossils and very rare trace fossils indicate deposition in a playa lake. Non-marine deposition in the region during the latest Early Triassic and early Middle Triassic helps constrain the location and timing of the initial marine transgression in the southern Germanic Basin.

Correction: Patrick Nadoll et al. REY and Trace Element Chemistry of Fluorite from Post-Variscan Hydrothermal Veins in Paleozoic Units of the North German Basin. Geosciences, 2018, 8, 283

The authors would like to correct the published article [...]

Encrinus aculeatus von Meyer, 1849 (Crinoidea, Encrinidae) from the Middle Triassic of Val Brembana (Alpi Orobie, Bergamo, Italy)

The Triassic crinoid Encrinus aculeatus is described from a single bedding plane of uncertain Pelsonian or early Illyrian or (less probable) late Ladinian origin from Val Brembana (Alpi Orobie, Bergamo, Italy) based on 36 more or less complete crowns and columns. The specimens represent an obrutional echinoderm lagerstatte of the Muschelkalk type. The individuals are semi-adult and juvenile; adult individuals are lacking. Morphological description and comparison with the holotype and additional material from the Lower Muschelkalk and basal Middle Muschelkalk of Upper Silesia (Poland) prove the assignment to Encrinus aculeatus. However, the species concept of genus Encrinus is critical because several characters are inconsistent. E. aculeatus occurs in the Middle Triassic (Bithynian to early Illyrian, ? early Ladinian) of the western Tethys shelf and Peritethys basins (Southern Alps, Balaton Upland, Germanic Basin). Encrinus aculeatus is regarded ancestral to the Upper Muschelkalk (latest Illyrian) E. liliiformis. Until now, E. liliiformis has not yet been proven with certainty from outside the Germanic Basin; references are based on isolated and undiagnostic material.

Deep geothermal resources of the North German Basin: The hydrothermal reservoirs of the Stuttgart Formation (Schilfsandstein, Upper Triassic)

Deep geothermal resources of the North German Basin: The hydrothermal reservoirs of the Stuttgart Formation (Schilfsandstein, Upper Triassic)

A continental record of the Carnian Pluvial Episode (CPE) from the Mercia Mudstone Group (UK): palynology and climatic implications

The generally arid Late Triassic climate was interrupted by a wet phase during the mid-Carnian termed the Carnian Pluvial Episode (CPE). Quantitative palynological data from the Mercia Mudstone Group in the Wessex Basin (UK) reveal vegetation changes and palaeoclimate trends. Palynostratigraphy and bulk organic carbon isotope data allow correlation to other Carnian successions. The palynostratigraphy indicates that the Dunscombe Mudstone is Julian and the lowest part of the overlying Branscombe Mudstone Formation is Tuvalian. The Aulisporites acme characterizing the CPE in Tethyan successions and the Germanic Basin is missing in the UK. The quantitative palynological record suggests the predominance of xerophyte floral elements with a few horizons of increased hygrophytes. A humidity signal is not seen owing to the dry climate in central Pangea. Also, the signal might be masked by the overrepresentation of xerophyte regional pollen and the predominance of xerophyte hinterland flora. The bias towards regional pollen rain is enhanced by the potential increase in continental runoff related to seasonally humid conditions and differences in pollen production rates and transport mechanisms. The vegetation of British CPE successions suggests a more complex climate history during the Carnian, indicating that the CPE is not recognized by the same changes everywhere. Supplementary material: A detailed lithological log of the Strangman's Cove (Devon) outcrop with the description of the Mercia Mudstone Group lithostratigraphical units, a description of the laboratory techniques, seven photoplates with selected spores and pollen grains, a list of all identified palynomorphs, Excel sheets with the palynological and palynofacies counts, bulk organic carbon isotope ratios and total organic carbon values of the Strangman's Cove outcrop are available at https://doi.org/10.6084/m9.figshare.c.4138085

Unusual archosaur trackway and associated tetrapod ichnofauna from Irohalene member (Timezgadiouine formation, late Triassic, Carnian) of the Argana Basin, Western High Atlas, Morocco

ABSTRACT An archosaur trackway consisting of 10 successive pes imprints has been recovered from the Late Triassic Irohalene Member of the Timezgadiouine Formation (Argana Basin, Morocco). Footprints are tetradactyl-pentadactyl, and show an elongated ‘heel’, probably enclosing the trace of digit V. The trackway lacks a manus impression, which could be due to bipedal progression of the trackmaker or be a preservational phenomenon. It is assigned to cf. Parachirotherium isp. based on similarities with the ichnogenus that has been described from the same stratigraphic unit. Other footprints of this assemblage are assigned to the ichnotaxa Grallator-Eubrontes (dinosauromorphs/crocodilian-stem archosaurs), Brachychirotherium isp. (crocodilian-stem archosaurs), Rhynchosauroides isp. (lepidosauromorphs/archosauromorphs), and indeterminate ichnotaxa. Associated with the footprints are numerous invertebrate traces such as Scoyenia gracilis. The ichnofauna of the Irohalene Member supports a cosmopolitan distribution of pentadactyl but functionally tridactyl chirotheres (Parachirotherium) and grallatorids across the Ladinian-Carnian boundary. Similar assemblages are known from the Germanic Basin and from Eastern North America. Furthermore, it documents the occurrence of very large Eubrontes trackmakers in the early Carnian. The depositional environment of the lower part of the Irohalene Member is interpreted as wet red beds of a flood basin transitional to a distal braid plain.

REY and Trace Element Chemistry of Fluorite from Post-Variscan Hydrothermal Veins in Paleozoic Units of the North German Basin

Hydrothermal fluorites from Paleozoic sedimentary rocks and volcanic units in the North German Basin (NGB) have been investigated to create a petrographic and geochemical inventory—with particular focus on strategic elements such as rare earth elements (REE)—and to uncover possible links between the post-Variscan hydrothermal mineralization in the NGB and bordering areas such as the Harz Mountains and Flechtingen Calvörde Block (FCB). Fluorites from ten localities underwent a detailed petrographic examination, including SEM-BSE/CL imagery, and were compositionally analysed using LA-ICP-MS. Overall, REY concentrations are comparatively low in fluorite from all investigated areas—the median sum of REY ranges from 0.3 to 176 ppm. EuropiumCN anomalies are slightly negative or absent, indicating that either the formation fluid experienced temperatures above 250 °C or that fluid-rock interactions and REE enrichment was likely controlled by the source rock (i.e., volcanic) composition and complexation processes. Fluorites from the Altmark-Brandenburg Basin (ABB) and the Lower Saxony Basin (LSB) display distinctly different REYCN signatures, suggesting that fluid compositions and genetic processes such as fluid-rock interaction differed significantly between the two areas. Complex growth zones and REYCN signatures in fluorite from the ABB and the FCB reflect geochemical variability due to adsorption processes and intrinsic crystallographic controls and imply that they are genetically related. Two petrographically and geochemically distinct generations are observed: Fluorite I—light SEM shades, relatively enriched in LREE; Fluorite II—darker SEM shades, comparatively depleted LREE, slightly higher HREE concentrations. These fluorite generations represent zoned (or cyclical) growth within a single progressive hydrothermal event and do not reflect a secondary remobilization process. We demonstrate that increasing Tb/La ratios and decreasing La/Ho ratios can be the result of continuous zoned growth during a single mineralizing event, with significant compositional variations on a micron-scale. This has implications for the interpretation of such trends and hence the inferred genetic evolution of fluorite that displays such geochemical patterns. The complex micro-scale intergrowth of these generations stresses the need for detailed petrographic investigations when geochemical data are collected and interpreted for mineral exploration.

The Keuper Group in the Stratigraphic Table of Germany 2016 – continuous sedimentation in the North German Basin (variant B)

The Keuper Group in the Stratigraphic Table of Germany 2016 – continuous sedimentation in the North German Basin (variant B)

Impact of saline aquifer water on surface and shallow pit corrosion of martensitic stainless steels during exposure to CO2 environment (CCS)

Pipe steels suitable for carbon capture and storage technology (CCS) require resistance against the corrosive environment of a potential CCS-site, e.g. heat, pressure, salinity of the aquifer, CO2-partial pressure. Samples of different mild and high alloyed stainless injection-pipe steels partially heat treated: 42CrMo4, X20Cr13, X46Cr13, X35CrMo4 as well as X5CrNiCuNb16-4 were kept at T=60 °C and ambient pressure as well as p=100 bar for 700 h - 8000 h in a CO2-saturated synthetic aquifer environment similar to possible geological on-shore CCS-sites in the northern German Basin. Main corrosion products are FeCO3 and FeOOH. Corrosion rates obtained at 100 bar are generally much lower than those measured at ambient pressure. Highest surface corrosion rates are 0.8 mm/year for 42CrMo4 and lowest 0.01 mm/year for X5CrNiCuNb16-4 in the vapour phase at ambient pressure. At 100 bar the highest corrosion rates are 0.01 mm/year for 42CrMo4, X20Cr13 (liquid phase), X46Cr13 and less than 0.01 mm/year for X35CrMo4 and X5CrNiCuNb16-4 after 8000 h of exposure with no regard to atmosphere. Martensitic microstructure offers good corrosion resistance.

Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)

Abstract. Bone tissue, microanatomy, and growth are studied in humeri of the pachypleurosaurs Dactylosaurus from the early Anisian of Poland and of aff. Neusticosaurus pusillus from the Lettenkeuper (early Ladinian) of southern Germany. Histology and modeled growth curves are compared to already published data of other pachypleurosaurs. Therefore, we herein established growth curves for Anarosaurus from the middle Anisian of Winterswijk (the Netherlands) and for pachypleurosaurs from the Anisian/Ladinian of the Alpine Triassic (i.e., Neusticosaurus spp. and Serpianosaurus). Humeri of Dactylosaurus, Anarosaurus, and aff. N. pusillus, all from the Germanic Basin, usually display an inner ring of (pre-)hatchling bone tissue. In some samples this tissue is surrounded by a layer of perpendicularly oriented fine fibers, which could indicate the start of active locomotion for foraging or might be related to viviparity. However, pachypleurosaurs from the Alpine Triassic do not show this tissue. This in turn could be related to overall differences in the environments inhabited (Germanic Basin vs. Alpine Triassic). Histological comparison revealed distinct taxon-specific differences in microanatomy and bone tissue type between Anarosaurus on the one hand and Dactylosaurus and the Neusticosaurus–Serpianosaurus clade on the other hand. Microanatomical differences imply a different degree in secondary adaptation to an aquatic environment. Life-history traits derived histologically and obtained from modeling growth were in general rather similar for all studied pachypleurosaurs. Onset of sexual maturation was within the first third of life. Asymptotic ages (maximum life span) considerably exceeded documented and modeled ages at death in all pachypleurosaur taxa. All traits modeled (more or less) matched values seen in similar-sized extant reptiles. Growth curves revealed differences in growth and maturation strategies within taxa that could indicate sexual dimorphism expressed in different adult sizes and a different onset of sexual maturation. Differences in gender size and morphology is well documented for the Chinese pachypleurosaur Keichousaurus and for Neusticosaurus spp. from the Alpine Triassic. Birth-to-adult size ratios of herein studied pachypleurosaurs were consistent with those seen in other viviparous Sauropterygia, other viviparous extinct taxa as well as extant viviparous reptiles. Anarosaurus had the highest maximum growth rates of all pachypleurosaurs studied, which best conformed to those seen in today's similar-sized reptiles and is expected from its bone tissue type. The other pachypleurosaur taxa had lower rates than the average seen in similar-sized extant reptiles. We hypothesize from our data that the considerably higher asymptotic ages compared to ages at death, early onset of maturation compared to asymptotic age, and viviparity reflect that pachypleurosaurs lived in predator-dominated environments.

Sedimentary noise and sea levels linked to land\u2013ocean water exchange and obliquity forcing

In ancient hothouses lacking ice sheets, the origins of large, million-year (myr)-scale sea-level oscillations remain a mystery, challenging current models of sea-level change. To address this mystery, we develop a sedimentary noise model for sea-level changes that simultaneously estimates geologic time and sea level from astronomically forced marginal marine stratigraphy. The noise model involves two complementary approaches: dynamic noise after orbital tuning (DYNOT) and lag-1 autocorrelation coefficient (ρ1). Noise modeling of Lower Triassic marine slope stratigraphy in South China reveal evidence for global sea-level variations in the Early Triassic hothouse that are anti-phased with continental water storage variations in the Germanic Basin. This supports the hypothesis that long-period (1-2 myr) astronomically forced water mass exchange between land and ocean reservoirs is a missing link for reconciling geological records and models for sea-level change during non-glacial periods.

Magnesium calcite in Muschelkalk limestones of the Polish part of the Germanic Basin

Magnesium calcite, which is usually observed in many natural low-temperature environments, was identified in Triassic limestones of the Polish part of the Germanic Basin. The occurrence of unstable magnesium calcite in Triassic limestones is remarkable. High-Mg calcite was identified in all beds of the Muschelkalk Karchowice Formation: Lower Crinoidea Beds, Lower Biohermal Beds, Upper Crinoidea Beds and Upper Biohermal Beds. The general chemical formulas of magnesium calcite of mentioned unites are: (Ca0.87–0.80,Mg0.13–0.20)CO3, (Ca0.83–0.75,Mg0.17–0.25)CO3, (Ca0.81,Mg0.19)CO3, (Ca0.78–0.77,Mg0.22–0.23)CO3 respectively. This mineral originated probably during the early stage of diagenesis, during compaction of limestones deposited in a warm, shallow marine environment. Some amounts of magnesium come from high-Mg skeletons of marine organisms (such as echinoderms). Diagnenetic processes and the conditions in seawater, especially higher salinity, influence the preservation of high magnesium calcite in the Muschelkalk limestone of the Polish part of the Germanic Basin.

Contrasting sources of Late Paleozoic rhyolite magma in the Polish Lowlands: evidence from U\u2013Pb ages and Hf and O isotope composition in zircon

The Polish Lowlands, located southwest of the Teisseyre–Tornquist Zone, within Trans-European Suture Zone, were affected by bimodal, but dominantly rhyolitic, magmatism during the Late Paleozoic. Thanks to the inherited zircon they contain, these rhyolitic rocks provide a direct source of information about the pre-Permian rocks underlying the Polish Lowland. This paper presents zircon U–Pb geochronology and Hf and O isotopic results from five drill core samples representing four rhyolites and one granite. Based on the ratio of inherited vs. autocrystic zircon, the rhyolites can be divided into two groups: northern rhyolites, where autocrystic zircon is more abundant and southern rhyolites, where inherited zircon dominates. We suggest that the magma sources and the processes responsible for generating high silica magmas differ between the northern and southern rhyolites. Isotopically distinct sources were available during formation of northern rhyolites, as the Hf and O isotopes in magmatic zircon differ between the two analysed localities of northern rhyolites. A mixing between magmas formed from Baltica-derived mudstone–siltstone sediments and Avalonian basement or mantle can explain the diversity between the zircon compositions from the northern localities Daszewo and Wysoka Kamieńska. Conversely, the southern rhyolites from our two localities contain zircon with similar compositions, and these units can be further correlated with results from the North East German Basin, suggesting uniform source rocks over this larger region. Based on the ages of inherited zircon and the isotopic composition of magmatic ones, we suggest that the dominant source of the southern rhyolites is Variscan foreland sediments mixed with Baltica/Avalonia-derived sediments.

A Middle Triassic pachypleurosaur (Diapsida: Eosauropterygia) from a restricted carbonate ramp in the Western Carpathians (Gutenstein Formation, Fatric Unit): paleogeographic implications

AbstractAn eosauropterygian skeleton found in the Middle Triassic (upper Anisian) Gutenstein Formation of the Fatric Unit (Demänovská dolina Valley, Low Tatra Mountains, Slovakia) represents the earliest known occurrence of marine tetrapods in the Western Carpathians. The specimen represents a partly articulated portion of the postcranial skeleton (nine dorsal vertebrae, coracoid, ribs, gastral ribs, pelvic girdle, femur and one zeugopodial element). It is assigned to the Pachypleurosauria, more precisely to theSerpianosaurus–Neusticosaurusclade based on the following combination of features: (1) small body size; (2) morphology of vertebrae, ribs and femur; (3) tripartite gastral ribs; and (4) microanatomy of the femur as revealed by μCT. Members of this clade were described from the epicontinental Germanic Basin and the Alpine Triassic (now southern Germany, Switzerland, Italy), and possibly from Spain. This finding shows that pachypleurosaur reptiles attained a broader geographical distribution during the Middle Triassic, with their geographical range reaching to the Central Western Carpathians. Pachypleurosaurs are often found in sediments formed in shallow, hypersaline carbonate-platform environments. The specimen found here occurs in a succession with vermicular limestones in a shallow subtidal zone and stromatolitic limestones in a peritidal zone, indicating that pachypleurosaurs inhabited hypersaline, restricted carbonate ramps in the Western Carpathians.

Middle Triassic conodont assemblages from the Germanic Basin: implications for multi-element taxonomy and biogeography

Conodonts have been a key tool for biostratigraphical, evolutionary and palaeobiogeographical studies, and the Germanic Basin has been one of the most important regions for these studies. However, few modern studies provide systematic data on the mainly endemic conodonts of the Middle Triassic Germanic Basin. Here we document conodonts from two sections in Germany, one Bithynian in age and the other late Anisian to early Ladinian in age. The two sections captured two episodes of marine fauna invasion in the Germanic epicontinental basin during the Middle Triassic. The conodont Neogondolella mombergensis, elsewhere reported as appearing globally, is reviewed and revised, confirming previous suggestions that this species only occurs in the Germanic Basin. Apparatuses of Neogondolella haslachensis and Nicoraella germanica from the Germanic Basin are proposed. It was generally expected that S and M elements within clades have a very high morphological stability compared to P elements. However, the apparatus of Nicoraella germanica differs significantly from that of south China, indicating that the morphology of S elements within a genus can be unstable, and thus promotes our understanding of conodont evolution. The rarely documented genus Gondolatus, which was suggested as representing pathological specimens, is confirmed as a valid genus in the Germanic Basin. Our data suggest that endemic conodonts evolved twice, not only in the Upper Muschelkalk Subgroup, but also in the Lower Muschelkalk Subgroup.