Fossils for sale we are digging : french Triassic upper Muschelkalk
Muschelkalk (literally translated from German as “shelly limestone” due to the great number of fossils found in it) is a subdivision of the Triassic period, which is in turn the first subdivision of the Mesozoic (or Secondary Era).
Chronologically, the Permian preceded the Triassic. It is the last period of the Paleozoic or Primary Era at the end of which occurred the biggest mass extinction that led to the disappearance of 95% of marine species and 70% of terrestrial species. The Triassic was succeeded by the Jurassic; then comes the Cretaceous. These stages are well known thanks to their fossils.
The Triassic lasted about 252 to 201 MYA. It gets its name from the 3 periods that it comprises in Germany:
• The Buntsandstein, at the base, corresponds to the sandstone sediments of a nearly desert continent.
• The Muschelkalk corresponds to the limestone deposits of a shallow inland sea.
• The Keuper, on top, corresponds to the marl deposits of a swampy continent where the sea had receded.
It is important to distinguish the Germanic Triassic —that interests us here— from the Alpine Triassic. The latter, equally divided in 3 periods, corresponds to an indisputably marine environment.
The Muschelkalk corresponds to the Middle Triassic and it is composed of 3 layers: the lower, middle and =upper Muschelkalk. We will look particularly at the upper Muschelkalk here, which is dated approximately 238.5 to 235 MYA. There are numerous outcrops in our region and it is only natural that we offer for sale fossils collected by ourselves.
Regarding stratigraphy, beds of thick limestone compose the base. It has practically no marls (crinoidal limestone), which are deposits of shallow water. Above, alternations of marls and limestone beds (ceratite limestone) correspond to deposits of a deeper sea of a few tens of meters. This, of course, is a simplified description.
Limestone beds are the result of severe storms whereas marls originated thanks to the sedimentation during quiet periods.
It is estimated that sea levels varied regularly during periods of transgression and regression of tens to hundreds of thousands of years.
The sea of the Muschelkalk is an inland sea communicating with the vast Tethys Ocean through only two sea gates to the southeast and southwest. It is for this reason that marine life is very different from that of the two oceans, Tethys and Panthalassa. This sea covered a large part of Germany and the eastern France, especially Lorraine.
2. Quarries and outcrops
In order to find fossils in Lorraine, as well as everywhere where the upper Muschelkalk emerges, one can search in the fields, but it is generally not there that we will find quality fossils. They are often very eroded or damaged by agricultural machines. It is better to focus on quarry areas or major works.
In Lorraine, several large limestone quarries exploit the upper Muschelkalk. They are privileged locations to find good quality fossils preserved from erosion and to observe the stratigraphy. We can also turn to major work areas such as the TGV East line that crosses the upper Muschelkalk over great distances, or the works of industrial areas, housing schemes or even roadworks.
Warning! It is important to always request the owner’s permission before digging on private property in order to avoid any inconvenience.
Life was relatively abundant in the Upper Muschelkalk sea, as evidenced by the numerous fossils for sale on our website that come from this layer. Although the fossils found are mostly cephalopods, i.e. ceratites and nautilus, on a closer look we see that they coexisted with a varied wildlife.
Marine reptiles such as nothosaurus or tanystropheus with their disproportionate neck hunted cephalopods, of course, but also fish of different species. This fish fauna also consisted of elasmobranchs (sharks and rays).
The placodus, which was also a large reptile, fed on the wildlife of the seabed such as the abundant shellfish with its grinding teeth.
Among all these animals, coexisted gastropods, or even various echinoderms, such as large fields of crinoids from the base of the upper Muschelkalk accompanied by brittle stars —brittle stars fossils for sale on our website— and even starfish as well as a few rare urchins. Several species of crustaceans complete the picture.
Now here is the detailed description of some common fossils in the upper Muschelkalk:
Ammonoids are represented only by the genus Ceratites, many fossils of which are available on our website. We distinguish 12 areas of Ceratites, but only 10 are found in Lorraine. The 2 basal areas —of Ceratites atavus/flexuosus and Ceratites sequens/pulcher— are not located in France.
Ceratites represent a population of cephalopods with a very different morphology from that on those 2 huge oceans, Tethys and Panthalassa, simply because they have evolved separately in a distinct environment. Only very basal forms as Ceratites atavus show similarities with their cousins because they evolved from a common ancestor —for more pictures, refer to the Ceratite fossils for sale on our website.
One aspect to easily recognize Ceratites is the very characteristic shape of suture lines found in all species of the genus from the oldest to the most advanced, without major changes throughout the phylogeny.
In addition, Ceratites are systematically preserved as internal mold; the shell is never present. Therefore, sutures are always visible.
Let us look more specifically to some typical fossil species found in Lorraine:
- Ceratites evolutus owe their name to their very evolute morph with a quite open umbilicus. Their size is at 10 centimeters or slightly above. They can be found in large quantities even if their conservation is generally average.
- Ceratites spinosus owe their name to their heavily ribbed costules (spino = “thorn”). The general shape becomes thicker and larger with an squarer underside. Their size is usually 10 to 15 centimeters, but can reach up to 20 centimeters in larger specimens.
- Ceratites enodis are a species with a particular morphology in the genus. They are perfectly smooth without ribbing whereas the species Ceratites posseckeri (sexual dimorphism) has lateral and ventral tubercles that become costules upon approaching inner chamber. Their size is smaller than the previous species, Ceratites spinosus, because the genre suffered a crisis during evolution. Ceratites enodis are among the least common in the Upper Muschelkalk because the population decreased significantly as a consequence of the crisis.
- Ceratites nodosus represent the best-known species of the Upper Muschelkalk because they are found frequently but also because they areoften confused with other species; many were first described under this name before being renamed. The shape becomes relatively massive and thick compared to the oldest species, often with a strong ribbing. Their size is typically 15 to 20 centimeters but can be up to 30 centimeters.
- Ceratites (subgenus Discoceratites) semipartitus represent the most advanced species but also the most extreme and largest morph. They have very wide and flat flanks without ribbing with a very thin discoid general shape (hence the name Discoceratites). The species Ceratites (Discoceratites) meissnerianus (sexual dimorphism) is very similar but has a slight ribbing on the phragmocone. Their size can reach or even exceed 40 centimeters. The genus became extinct at the peak of the Upper Muschelkalk.
Ceratites enodis (10cm)
Ceratites spinosus (12cm)
Ceratites semipartitus (30cm)
Nautiloids are represented only by the genus Germanonautilus. The predominant species present in all levels is Germanonautilus bidorsatus whose size can easily be expected to exceed 20 centimeters.
Two other species may be discovered but their presence is more anecdotal. These are the Germanonautilus tridorsatus and Germanonautilus suevicus (For more photos, see our fossils for sale). The latter ones are characterized by tubers that come out of each side of the abdomen. Often, only isolated chambers are found. However, the discovery of masticatory apparatus (Rhyncholites) or "beaks" of Nautilus may be more common.
Gastropods can be found more or less frequently depending on the location and levels. The most common species is Loxonema obsoletum, whose size can reach 10 centimeters. The shape is relatively elongated with a dextral coil.
More rarely, the genus Undularia can be found, whose shape is close to Loxonema but with a more compact coiling and winding towers, or even the genus Neritaria, smaller, larger and much stockier —again, many pictures in our fossils for sale.
The most common bivalves are the molds of Hoernesia socialis. As their name suggests, they are often found in groups and their size is about 5 centimeters.
The species Entolium discites and Pleuronectites laevigatus are also quite common. Their general shape is wide and quite rounded; their size can exceed 10 centimeters.
Plagiostoma striata have a smaller size and a highly ridged shell
—hence the name.
Myophoria, the ancestors of Trigonia can reach 10 centimeters and can also be found in groups, sometimes of tens of individuals.
Association Loxonema obsoletum et Hoenesia socialis
Brachiopods are poorly represented almost exclusively by the species Coenothyris vulgaris, whose fossils are often found in groups. Much more anecdotal are the fossils of inarticulate brachiopods of the genus Lingula. Other species are described (Tetractinella and Spiriferina), but only in the German Upper Muschelkalk.
Echinoderms are also present.
The crinoids Encrinus liliiformis that can reach the respectable size of 1.5 meters with crowns of 10 to 15 centimeters are the best known. They are only found in the crinoidal limestone that constitutes the basal levels of the upper Muschelkalk. These crinoids lived attached to the seabed in large colonies. The discovery of a full crown remains uncommon in Lorraine. Nevertheless, you will still find a selection of chalices among our fossils for sale.
Brittle stars are represented by 3 species: short, thick arms characterize Aspiduriella scutellata, while Aplocoma agassizi and Arenorbis squamosus have thinner and longer arms. Their size in centimeters remains modest.
Very rare in the upper Muschelkalk of Lorraine, the starfish Trichasteropsis weissmanni reaches 10 centimeters and has 5 relatively short arms and a stocky body.
Regular urchins of the only genus Cidaris also remain extremely rare, although several species have been described.
The best-known crustaceans are the decapods Pemphix sueuri whose size reaches 10 centimeters. They can be found in all levels, most often in nodules. Complete specimens remain a great discovery; it is more common to find only cephalothorax, which are actually exuviae, i.e. moulting.
Other genus are described but much rarer, namely Pseudopemphix, Lissocardia or Aspidogaster.
Nothosaurus mirabilis tooth
Vertebrates are found in all levels of the upper Muschelkalk. One can discover their remains as nodules, but also in bone beds that can be very rich.
Nothosaurus are emblematic marine reptiles of Upper Muschelkalk, reptile hunters with a very elongated skull provided with fine and long teeth. They lived on land and hunted marine wildlife.
It is not uncommon to find vertebrae, ribs or teeth. The discovery of a skull or part of a skeleton is of course exceptional but not impossible.
We mainly distinguish two genus: Nothosaurus mirabilis and Nothosaurus giganteus. The latter could reach the respectable length of 3 meters.
Another semi-aquatic reptile known on this level is the Placodus gigas. It fed on the seabed fauna, mainly shellfish, whose shell it crushed with its broad, flat teeth, easily recognizable and that cannot be confused with others. Its length reached 2 meters and its body was stockier and less streamlined than that of the nothosaurus because it was not a hunter.
More rarely, it is possible to discover the remains of tanystropheus, an aquatic reptile 5 to 6 meters long, with a disproportionate neck of very long cervical vertebrae.
Placodus gigas tooth
Several species of elasmobranchs (sharks and rays) are known in the Upper Muschelkalk.
Sharks of the genus Hybodus, whose descendants have lived up to the upper Cretaceous, were hunters of thin and very sharp teeth that can be found quite easily in bone beds. Dorsal spines of these sharks can reach 20 centimeters and are bordered by denticles.
On the contrary, Sharks of the genus Acrodus were grinders; their broad, flattened teeth are often found isolated, but more or less complete palates have already been discovered.
Rays of the genus Palaeobates are also recognizable by their rectangular and flat teeth.
Hybodus shark dorsal spine
Acrodus shark tooth
Hybodus shark tooth
Fish also represented an important part of the marine fauna. They are always kept in nodules, and are therefore generally complete.
We can name the genus Colobodus, a grinder fish of a size up to about 50 centimeters of which complete dental palates are sometimes found.
Another genus, Gyrolepis, could also reach a similar size.
Also known are the Saurichthys (carnivorous fish with a very slender body) of Cœlacanths or even Dipnoi of the genus Ceratodus kaupii, whose dental palate characteristics remain infrequent
Colobodus fish found in a concretion
Contrary to popular belief on the Upper Muschelkalk, we can see that marine life is diverse (see the numerous fossils for sale on our website), even though Ceratites remain the most known and most frequently found fossils. The species described above constitute a far from exhaustive list. Mixosauria, crocodilomorphes or even amphibians have also been described, but these are very rare.
Regarding the determination of fossils of the Upper Muschelkalk but also of the whole Germanic Triassic, from Buntsandstein to the Keuper, the main reference is Die Lebewelt unserer Trias, by Martin Schmidt, written in German and the first edition of which dates from 1928. Although a number of species, particularly Ceratites, have been renamed and their numbers have been reduced since, this book remains an indispensable basis.
There are numerous publications on the Upper Muschelkalk, and almost all of them are written in German.
Finally, for the preparation of fossils of the Upper Muschelkalk, several methods are possible. Pneumatic pens remain the indispensable basic tool, but according to the type of fossil other tools or products are useful, namely sandblasters, mainly for finishing work, or potash —handle very carefully— for fossils such as echinoderms (crinoids, brittle stars or starfish). Using a dissecting microscope of high magnification for delicate work such as the umbilic of Ceratites or the teeth of Hybodus is also a great help.
See our article :
for a specific example.
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