Geiseltal fossil deposit

View over the western Geiseltal from the south, in the background the spoil dump near Klobikau

View over the central Geiseltal from the north, in the background the spoil dump near Pfännerhall

The Geiseltal fossil deposit is located in the former lignite mining area of the Geiseltal south of the city of Halle in Saxony-Anhalt . It is an important finding place of now extinct plants and animals from the time of the Middle Eocene 48 to 41 million years ago. There is evidence that coal was mined in the Geiseltal for the first time in 1698, but the first fossils only came to light by chance at the beginning of the 20th century. Scheduled scientific excavations began in 1925 by the Martin Luther University Halle-Wittenberg . Interrupted by the Second World War , the investigations can be divided into two research phases. Due to the increasing carbonization of the raw material deposits, excavations gradually came to a standstill in the mid-1980s and finally ended at the beginning of the third millennium.

The lignite of the Geiseltal is subdivided into four main seams , mainly the three lower ones were fossil-bearing. The focus of the fossil distribution is in the southern and central Geiseltal. The finds include remains of plants and animals. A special feature are almost complete finds with leaves, fruits and trunks, but also skeletons of vertebrates and remains of insects . One of the best-known finds is that of a complete skeleton of the primeval horse Propalaeotherium from 1933. There are also vertebrates such as the ungulates , small mammals such as insectivores and bats as well as birds , crocodiles , turtles , snakes , amphibians and fish . Remnants of soft tissue have also been found in numerous vertebrates . A total of more than 80 individual sites with more than 50,000 objects are known, including 36 with a significant number of vertebrates. Due to the good and extensive fossil conservation, the Geiseltal is considered a conservation and concentrate deposit .

The specialty of the Geiseltal fossils, especially of the vertebrates and especially of the mammals, lies in the unique preservation in lignite, which does not otherwise occur in Central Europe. The Geiseltal is an important site for the development of mammals, as the development of individual groups can be observed over a period of several million years. As a result, the mammalian fauna is the reference for the Geiseltalium , a section from the stratigraphy of European land mammals from 47 to 43 million years ago. The extensive finds from the animal and plant world, but also the numerous geological data, enable a very precise reconstruction of the landscape. As a result, at the time of lignite formation, there was a multi-storey low forest near the coast, which was interspersed with streams, ponds and moors. The forest was influenced by the subtropical climate and was home to a rich fauna. The entire fossil record of the Geiseltal is under national protection.

Geographical location

Geiseltal opencast mining area, mapped at the 2 m limit of the lignite thickness

The Geiseltal , a peripheral area of ​​the Central German lignite mining area , is located around 20 km south of Halle (Saale) and around 10 km southwest of Merseburg in Saxony-Anhalt. It extends over a length of 15 km from west-northwest to east-southeast and a width of 0.5 to 5 km. In the north it borders on the flat Merseburg red sandstone slab, in the south on the Müchelner Muschelkalkplateau of the Querfurt-Freyburger Mulde . The Geiseltal is traversed by the eponymous river Geisel , which rises in St. Micheln near Müchi from one of the largest spring or overflow springs in Central Germany and drains into the Saale after 19 km in Merseburg via the Gotthard ponds. Its catchment area is about 35 km².

Originally the area of ​​the Geiseltal was relatively flat, which can be explained by the red sandstone spreading west of the Saale . In general, the heights in the eastern Geiseltal were around 100 meters above sea level, to the west they rose to 150 meters and more. Due to the intensive activity of the lignite opencast mines , the landscape has been seriously changed, especially in the last 150 years, and in addition to the destruction of several localities, it also led to the overprinting of an area of ​​around 90 km² with multiple relocation of the Geisel river to the south. As a result of the renaturation of the later abandoned opencast mines, larger lakes were created that currently define the entire Geiseltal. As early as the second half of the 20th century, the Südfeldsee and Runstedter See were created in the eastern and south-eastern Geiseltal , while the Geiseltalsee , one of the largest artificial lakes in Central Europe , was not completely flooded until 2011. The western and eastern Geiseltal are now separated by an up to 140 m high Kippendamm which, in addition to the current course of the Geisel, also carries important traffic routes such as roads and rails.

geology

Geological subsoil

Geological structure of the Geiseltal in the block diagram

The geology of the Geiseltal has been well investigated since the beginning of the 20th century in preliminary investigations to establish the storage conditions of the lignite with deep boreholes. These were only 100 meters apart in individual sections. The geological subsurface consists largely of deposits of Rotliegend and Zechstein from the Permian geological period around 300 to 240 million years ago. The sediments of the red sandstone (251 to 243 million years ago) are deposited on these , with the lower and middle red sandstone predominantly occurring. In the southern part of the Geiseltal towards the Müchelner Muschelkalk plateau, however, there are also remains of the Upper Buntsandstein, on which the shell limestone deposits lie in the edges of the valley . The following hiatus includes the Keuper and the Cretaceous from a period of about 140 million years.

Today's Geiseltal is divided in several ways. The Neumark main threshold, an elevation of the Buntsandstein, divides it into roughly two equal areas, the western and eastern Geiseltal. Secondary and subordinate basins are the Elise Kessel, Elisabeth Kessel, Wernsdorfer Kessel and other pre-tertiary thresholds are the Kayna threshold and the east threshold. Geologically, the Geiseltal represents a subsidence structure, the origin of which has not yet been fully clarified, but which has been controlled by several processes. May have resulted in the Paleogene the leaching of Zechsteinsalzes connected to the chemical weathering of the Muschelkalk ( Subrosion ) in mass loss in the ground, resulting in a lowering of the auflagernden layers and the basin formation had resulted. Above all, the salt movement ( halokinesis ) was related to tectonic forces in the subsurface, resulting from plate tectonics , which also caused the folding of the Alps during the Cretaceous / Tertiary transition about 65 million years ago. This increased the pressure on the originally flat Zechsteinsalinar , which then flowed off to the side. In the northern part of the Geiseltal, seismic measurements were used to determine tectonic faults, the so-called Geiseltal-Nordrand-fault, which in some cases reaches a jump height of up to 200 m in the upper layers (red sandstone).

Paleogenic deposits

The entire paleogene deposits in the Geiseltal reach a thickness of up to around 200 m, but are largely limited to the Eocene (56 to 34 million years ago). These are introduced tertiary sediments of clays and silts and partly gröberklastisches material. The thickness of the mostly finely stratified to leafy lignite is around 30 to 80 m, but in some places it also reaches over 120 m. In general, Geiseltal lignite is divided into four main seams , lower coal, middle coal (differentiated into lower and upper middle coal) and upper coal, but in the northern Geiseltal it still has a local base coal. Except for the base coal, all seams are subdivided into further seam sections. The individual seams reach a thickness of 10 to sometimes 60 m. They are interrupted by sandy- silty sediment sections (the so-called main resources), which represent guiding horizons and serve to differentiate the seams. In the southern Geiseltal in the Cecilie opencast mine , however, there was a partially complete transition from the middle coal to the upper coal. The extent of the individual coal seams from north to south is different and tied to the halokinetic and subrosive subsurface subsoil, but it generally continues further south with the increasing stratigraphic altitude of the seams. Only the upper coal is fully developed in the Geiseltal. The very rich Eocene fossil community comes primarily from the Lower Coal and the Middle Coal.

Overlying layers

The overburden in the Geiseltal consists of up to 50 m thick deposits of the Middle Pleistocene and Young Pleistocene (0.78 to 0.012 million years ago). The oldest layers spared from erosion were deposited as ground moraine by the inland ice of the Elster Glaciation (400,000 to 335,000 years ago). In the Holstein warm period (335,000 to 320,000 years ago) the Unstrut shifted its course into the Geiseltal and filled up the so-called Körbisdorfer terrace. The inland ice of the Saale Glaciation (320,000 to 128,000 years ago) crossed the Geiseltal only during the first foray, known as the "Zeitz phase" in central Germany and the "Drenthe I phase" or "main Drenthe" in northern Germany .

The retreat of the inland glacier of the Saale glaciation led, particularly in the northeast part of the Geiseltal, in the former Neumark-Nord opencast mine, to the formation of drainless and mostly water-filled depressions, in which predominantly limnic sediments were deposited , due to Mollisol diapirism . The individual lake basins were the focus of interdisciplinary scientific studies between 1986 and 2008, the results of which have been published in a large number of publications. The largest, around 600 m long and 400 m wide Neumark-Nord 1 basin contained the remains of a rich large mammal fauna with partly complete skeletons, including European forest elephants , aurochs , bison , fallow deer and various rhinos ( wood rhinoceros , steppe rhinoceros ), but also cave lions and the spotted hyena . The large mammal fauna of the smaller Neumark-Nord 2 basin was basically similar to that of the larger one, but with a few exceptions was small and disarticulated. A large number of flint artifacts of the Middle Paleolithic man were discovered in the bank areas of both basins . There is still no agreement on the age. According to various pollen analyzes , the warm-period sediments of the two basins show a succession typical of the Eem warm period (128,000 to 115,000 years ago). For the Neumark-Nord 2 basin, an eemzeit classification is supported by further analyzes, such as paleomagnetics and radiometric age dating. In contrast, the warm-time sediments of the Neumark-Nord 1 basin could also have been deposited in an “intra-eel-period” warm period. Indications for this are provided by the botanical remains, such as the macroflora with the extremely rich relics of a steppe-oak mixed forest characterized by the Tatar maple , or individual key fossils of small mammals, including the dwarf wood mouse Apodemus maastrichtensis . Neither the ostracodal fauna nor other findings speak for a warm age.

The entire layer package is discordantly overlaid by gravel from the Geisel and the several meters thick loess of the last glacial period ( Vistula glacial period ; 115,000 to 11,600 years ago), which carries the black earth soil . Various ice wedge horizons are embedded in the loess, referring to the particularly cold phases of the last glacial period . The late section of the Vistula glacial period is more open on the southern edge of the Geiseltal (former open-cast mine in Müuellen). Here, four warm-cold phase cycles could be detected in a small depression, of which the two upper ones can be correlated with the Bölling interstadial (in the classical sense) and the Older Dryas period as well as the Alleröd interstadial and the Younger Dryas period . In the most recent, warmer episode (Alleröd-Interstadial) just below the recent soil horizon, a thin layer of the Laacher-See-Tuff has been preserved as a relic of a volcanic eruption around 13,000 years ago.

Fossil sites

Fund preservation and distribution

Stratigraphic distribution of vertebrate sites

Spatial distribution of the vertebrate sites in the western and central Geiseltal

Calcite ball from the Geiseltal, placed in the garden of the Zoological Institute of the Martin Luther University Halle-Wittenberg; Diameter 1.5 m, weight 5 t; created by the penetration of calcareous water into the fossil-bearing coal

While plants and sometimes invertebrates were found in all areas of the coal seams, vertebrates were tied to certain, more limited sites. A total of more than 80 sites are known, 36 of which have a significant population of vertebrate remains. These are mainly located in the lower and middle coal, with around twice as many sites in the middle coal as in the lower coal. The upper coal contained only one relevant site and was otherwise largely fossil-free, which is partly due to the diagenetic changes during the Pleistocene under the influence of periglacial conditions. No fossilization could be detected in the base coal . The spatial distribution of the vertebrate fossil sites reflects the prerequisites for the preservation of finds, which were not given to the same extent in the entire Geiseltal. As a result, the greater part of the vertebrate sites, especially those with partially complete skeletons or soft tissues, are concentrated in the central and southern Geiseltal, mainly near the Neumark main threshold and in the Wernsdorf basin to the east. The majority of the sites are therefore in the Cecilie , Leo , Geiselröhlitz and Pfännerhall opencast mines and are spread over an area of ​​around 20 km². The quality of fossil conservation decreases sharply to the north and west and partly to the east.

Vertebrate finds made from lignite are very rare worldwide and have not yet been observed outside the Geiseltal in Central Europe . There are several reasons for the good fossil conservation in the Geiseltal. Mainly responsible are calcareous waters from the adjacent Triassic rocks, here mainly shell limestone , which penetrated from the south or south-west from the Querfurt-Freyburger Mulde area during the formation of the lignite as circulating groundwater. These largely neutralized the decomposing properties of the humic acid found in the fens in what was then the Geiseltal, but were only locally effective, as can be seen from the find picture. To a lesser extent, silica also ensured that the fossils were well preserved. Another influence on the preservation of the animal carcasses was the flooding of the former land surface, mostly found in the middle coal, which led to the carcasses being quickly covered with sediments. Both the fossil remains and the brown coal are 50% saturated with water when fresh and dissolve very quickly as they dry out by peeling and then disintegrating into dust. For this reason, the paint film method was developed as early as the early 1930s for the targeted recovery of fossils, especially in the Geiseltal .

Reference types

In addition to individual and scattered finds, as well as occasional finds from drill cores, a total of three different types of vertebrate sites can be distinguished, some of which also occur in different combinations:

• Collapse funnel

These are circular, partly dolphin-like depressions with a symmetrical structure. They were created syngenetically through leaching of gypsum in the red sandstone below ( subrosion ). As a rule, the collapse funnels can be recognized by their marginal layer faults and the resulting tectonic shifts. Two funnel types can be distinguished: the actual collapse funnel with diameters of 12 to 18 m and the settlement funnel, which is smaller and shallower and reaches a diameter of 3 to 8 m. When they were formed, the depressions were largely filled with water and formed small ponds and pools. The often steep edges formed natural traps for vertebrates, creating a natural burial community. The digested sludge formed by the rapid deposition of sediment on the pond floor and the anaerobic conditions prevailing there resulted in the formation of the fossils.

• Corpses fields

These are more extensive areas with fossil finds that extend over 80 to 100 m. The fossils are usually located in large depressions and are usually covered by a 20 to 30 cm thin layer of carbon. They are remnants of the former land surface and moor areas that were flooded by floods and are mainly concentrated in the central Geiseltal.

• Streams

The streams resembled the fields of corpses, some of which came from the western Muschelkalk region and ran through the Geiseltal valley and flowed into one of the local basins. There are channel-like depressions in the coal, in which mostly cross-layered quartz sands were deposited. Only in the lower pelvic areas were also argillaceous sediments found suggesting a reduction in the flow force of the streams. The fossil finds are concentrated on the former bank areas. Most of the animals died there, as with the collapse funnels, on the sometimes steep slopes, but were also victims of numerous predators living there.

Collapse funnels and fields of corpses are the most common, the streams are rather rare and were only discovered in the mid-1950s. The conservation status of the vertebrate fossils in the corpse fields and in the streams is similar and shows certain rearrangements due to water movement combined with skeletal decay. In the collapse funnels, complete skeletal remains were only found in the central and deepest places where the carcasses were completely covered with water. Clear disarticulations of the skeletons can also be observed towards the edges of the funnels. The significant finds of the fossilized soft tissue come only from the collapse funnels and the corpse fields.

Finds

Left: Distribution of the vertebrate finds in the Geiseltal valley among the vertebrate groups - Right: Detailed section of the finds within the mammals

The fossil material from the brown coal of the Geiseltal is very rich and includes remains of plants and animals. The floristic material is in the form of micro and macro residues. The fauna is represented by invertebrates and vertebrates , of the latter there are also a large number of full skeletons. The good conservation of soft tissue should be emphasized , which fossil remains very poorly preserved. Despite the good conservation conditions, a larger part of the fossils is not deposited autochthonously , but was transported during fossilization, caused by the flow of water. This mainly applies to the finds from the corpse fields and the streams. The storage conditions of the fossils are generally to be regarded as parautochthonous to partially allochthonous . The exact number of finds is unclear, the holdings of the former Geiseltal Museum of the University of Halle comprise around 50,000 objects, most of which are vertebrates. During the intensive excavation phase of the 1960s, the inventory grew by more than 5830 objects a year. An analysis of more than 10,000 vertebrate remains revealed almost half mammals with 5000 pieces , while reptiles are the second most common with 2000 finds. The scientific evaluation of the total stock of fossils continues, numerous fossil living beings received their first description based on the finds from the Geiseltal . The vertebrates alone comprise more than 120 taxa .

flora

Sintered tree trunk from the Geiseltal, set up in the garden of the Zoological Institute of the Martin Luther University Halle-Wittenberg; original height 4.7 m, largest trunk diameter 0.9 m, split into two parts

Branch and leaf fragments from Doliostrobus from the Geiseltal

Among the very common plant residues, in addition to pollen and spores as microflora, which alone contain more than 100 stratigraphically relevant taxa, especially the macro residues are of importance. These include leaves, twigs, branches, bark, and stems, as well as fruits, seeds, and inflorescences. At least 18 families can be identified from the fruits and seeds alone . In total, more than two dozen families with around 40 genera are known. In addition to algae , mosses , primeval ferns and ferns - some of them in concentrated accumulations of ribs and climbing ferns , among other things - remnants of the more highly developed seed plants are predominantly found. The naked species are represented by cycads , some with whole fronds, and conifers with cones and twigs. The latter include, among other things, pines and sequoias , some of which are concentrated. The latter are classified in the cypress family, of which the extinct genus Doliostrobus has also been passed down. The remains of the bed covers are much more extensive . Here the dicotyledons are the largest group with around 20 families. These include the laurel family and beech family . The latter sometimes also form dense leaf layers, such as in the genus Dryophyllum . Gail plants , predominantly fern myrtle , are very common. Plant remains that have been documented in large numbers come from the linden family , icacinaceae and myrtle family , of which Rhodomyrtophyllum is dominant. The long, narrow leaves of Apocynophyllum from the group of dog poison plants are also characteristic . Bark remnants and the so-called "monkey hair", fossilized milky sap tubes, are also assigned to this plant family. Monocots have less variety. Among these, there are mainly palm trees in large numbers and are represented by Sabal and Phoenicites , among others . The palm trunks that are often handed down cannot, however, be precisely assigned taxonomically. Further representatives of the monocot have also been described, for example from the group of the lily family and the screw tree family .

fauna

Invertebrates

Gastropod Schill from the Geiseltal

Invertebrates were first mentioned in 1913 and are very numerous. Mollusks , to which mussels and snails belong and which sometimes appeared in large numbers, are represented by around 20 genera and are ideally suited for the reconstruction of small biotopes. The same applies to the ostracods , the mussel crabs with 10 genera. Further finds of arthropods are assigned to the decapods . However, with only 15 copies, these are extremely rare and mostly only preserved with remains of the armor. The most common invertebrate finds are insects . The beetles dominate here and the jewel beetles (28%) dominate . The genus Psiloptera has been identified with eight species, but Buprestis and Anthaxia are also represented with several species. Among the longhorn beetles , recognizable by the extremely long antennae, is Xyleoconites expected while Eocallidium within the group of darkling beetle stands. There are also some other families of beetles , including the scarab beetles , the hook beetles and the leaf beetles . Since the insects are almost exclusively preserved with their backs, the sometimes splendid coloring of the animals has been handed down, but the exact identification of the species cannot be made with certainty in all cases. Also flying insects such as mayflies and dragonflies could be detected, damselflies but only tiny, only a few millimeters large egg clutches. These are deposited in double rows on the leaf of a Bedecktsamer and are similar to those left behind by pond maidens today ("Lestiden" type). The group of flying insects also includes the fan-winged winged winged insect , whereby a larva of Pseudococcites only 140 μm long and 90 μm wide from the excrement of a beetle forms one of the few documents worldwide of this developmental stage of the insect group. Spiders and millipedes occur in very small numbers . The discovery of a string worm of the genus Gordius , which parasitizes insects, is a specialty, since such parasites are extremely rare in fossil form.

Fish and amphibians

Skeleton of Eopelobates from the Geiseltal

The fish fauna is very extensive with around 2000 finds, including many complete skeletal individuals, but only includes 5 families with as many genera. The most common are the bony fish , represented by Thaumaturus and Palaeoesox . The former belongs to the salmon- like family , the latter to the pike-like family . Anthracoperca , a relative of the perch, is also a bone fish . With Cyclurus there is also a representative of the bone organoids .

Among the amphibians , the frogs and newts are predominantly of importance, with 200 to 300 specimens each, plus numerous individual bones. The articulated skeletons of the frogs are all very fragile. Eopelobates is a very common member of the European spadefoot toad family , to which today's common spadefoot toad also belongs. Like them, Eopelobates lived largely terrestrially. In contrast, the equally common Palaeobatinopsis was a water-dwelling animal from the family of the Palaeobatrachidae , a group of frogs that is now extinct. Other fossil material may well belong to a closely related representative. Of the newts, Palaeoproteus is particularly numerous. It is an amphibious olm that was up to 25 cm long and had very short limbs. Tylototriton occurs less frequently . This genus, known as crocodile newts, still occurs in East and Southeast Asia and its representatives belong to the real salamanders .

Reptiles and birds

Tanks from Borkenia from the Geiseltal

Skeleton of Geiseltaliellus from the Middle Eocene of the Geiseltal

Skull of Eosaniwa from the Geiseltal

Reptiles are among the most common fossil finds and can be assigned to nearly a dozen families with around 20 genera. Due to the humid environment, numerous turtles have survived, especially their shell remains, which are mostly flattened by the sediment load. All the turtles known from the Geiseltal can be counted among the Halsberger turtles and comprise around 500 specimens. These include the species-poor genus Geoemyda from the group of Old World pond turtles with a roughly 18 cm long, well-ossified shell. At the other end of the scale is Geochelone , a tortoise that had a shell up to four feet long. Other, rather smaller forms are Hummelemys and Borkenia . The latter was formerly part of the genus Chrysemys and thus related to the ornamental tortoises . Among the soft-shelled turtles belongs Palaeoamyda whose tanks reached approximately 30 cm in length. The animal was well adapted to freshwater life.

Skeleton of Paleryx from the Geiseltal

Scale reptiles have been recorded with almost 300 complete specimens plus numerous individual finds. Here was Eolacerta quite a large animal that was 60 cm long and complete with several skeletons and also remains molting is handed down. It was originally counted among the real lizards , but some special anatomical features led to the establishment of the independent family of the Eolacertidae , which in turn forms the sister group of the real lizards. Among the iguanas is Geiseltaliellus to provide a slightly built lizard with extremely long tail and fine Hautbeschuppung, which probably was a tree dweller. Due to the short forelegs, it is assumed that Geiseltaliellus, like today's basilisks, could occasionally only move on its hind legs. Ophisauriscus can in turn be assigned to the sneak and is related to the glass sneak . The snake-like animals still had rudimentary front and rear limbs. More than 20 finds have been documented, the state of which ranges from almost complete skeletons to disarticulated individual finds and remains of the skin armor. The individual bone platelets of the former shed dress differ markedly in shape and ornamentation from today's forms. Relatives of today's monitor lizards rarely appear . A poorly preserved partial skeleton from Eosaniwa has a 19 cm long skull, making this lizard one of the largest in the Geiseltal. A good 60 complete specimens are to be counted among the snakes , which have been handed down among other things with two genera of the giant snake from the boas family . It was Paleryx up to 2.3 m long, with a nearly complete specimen 243 vortex could be detected in total. Furthermore, palaeopython occurs, as well as some roller snakes .

Skull of Diplocynodon from the Geiseltal

Skeleton reconstruction of Boverisuchus from the Geiseltal

There are also large numbers of crocodiles with around 120 complete skeletons, plus countless isolated bones and teeth. The alligators are represented by Allognathosuchus , which was only about 0.8 m long and had a rather narrow snout. Diplocynodon is one of the most common crocodile forms in the Geiseltal and is classified in the extinct group of Diplocynodontidae . It lived in smaller bodies of water and reached a length of 1.3 m. One particular find includes a nearly complete skeleton with bone armor and five eggs in close proximity; it is one of the world's rare examples of brood care in fossil crocodiles. Boverisuchus , one of the real crocodiles, is somewhat larger and also numerous, at 1.7 m in length . Due to the relatively long limbs and hoof-like end links of the toes, a more terrestrial way of life is assumed for this crocodile. The largest predator in the Geiseltal was the Asiatosuchus with a body length of around 3 m. It was ecologically similar to today's Nile crocodile and preferred open waters. He is proven with several complete skeletons. On the other hand, Bergisuchus appeared extremely rarely with only a few lower jaw fragments , a possibly also more land-dwelling animal, which was 1.5 m long and stunted . In contrast to the other forms, Bergisuchus represents a primeval and more distant crocodile relative from the group of Sebecosuchia . Detailed studies have shown that all crocodiles in the Geiseltal occupy different ecological niches . In addition, there are fragments of crocodile eggs and numerous gastroliths (stomach stones), which prove the presence of crocodiles even without fossil conservation.

Skeletal remains of Strigogyps from the Geiseltal

Skeleton reconstruction of Gastornis from the Geiseltal

The remains of birds that have been identified with around half a dozen families and a good twice as many genera are rather rare . Most of the time, only the remains of extremities have survived. A relatively small representative palaeognathae represents the rear on the extremities and also has a partial skeleton proven Palaeotis . It was originally regarded as related to the bustard , but later considered to be part of the ancestral line of today's ostriches . In addition to the clear characteristics that Palaeotis unites with the primeval jawbirds, some characteristics of the hind legs are more reminiscent of today's cranes . With a total height of up to 1.8 m, Gastornis (also called Diatryma ) was significantly larger . There are more than three dozen objects found from this large ground-running bird, including several leg bones, but also skull remains and parts of the wings, which represent the largest collection of all sites in Europe. For a long time Gastornis was considered to be a carnivore, but isotope tests on some bones from the Geiseltal showed that the bird was mainly vegetarian. Eocathartes was originally counted among the real carnivorous birds . This should represent the New World Vultures in the Geiseltal and has been described using parts of the body skeleton as well as feathers. Furthermore, Geiseloceros had an exotic status as a member of the hornbills . It was documented by leg bones and contiguous remains of wings, on which the blue shimmering wing feathers can also be recognized. Both taxa are now grouped as strigogyps from the Ameghinornithidae family , a group of larger ratites. Aegialornis , a fossil sailor , has also been detected over a humerus .

Mammals

The very extensive mammal fauna includes remains from around two dozen families with more than 50 genera. The marsupials , represented by Peratherium and Amphiperatherium , are among the most primitive representatives . There are several skull and lower jaw remains, especially from Peratherium . Both genera are ancestors of the South American opossum . Microtarsioides , on the other hand , is difficult to classify in terms of taxonomy , since a relatively complete skeleton has been passed down, but it comes from a juvenile animal.

Skeleton of Leptictidium from the Geiseltal

The higher mammals are much more extensive and varied . A few characteristically strong long bones are assigned to Eurotamandua . Originally, as a member of today's anteaters regarded, but he is after further investigation a Basalform the pangolins with similar lifestyles are. Among the small mammals belongs Heterohyus , a Apatemyide which extended by two fingers and arcuate incisors is characterized. The enlarged front teeth were used to gnaw tree bark, and he used his long fingers to dig into cracks and cracks for insects. In its way of life, Heterohyus was similar to today's finger animal of Madagascar. Leptictidium has been identified with a partial skeleton and a lower jaw . This predatory animal moved by jumping on its hind legs, which indicates the basal position of the Leptictida , as this no longer occurs in today's insectivores . The rarely occurring Buxolestes , on the other hand, was a stocky, semi-aquatic animal from the Pantolestidae group , whose appearance and way of life roughly corresponded to today's otters . The Paroxyclaenidae are closely related, but only a 12 cm long skull of Vulpavoides and a 5 cm long lower jaw fragment of Pugiodens are documented. The short-snouted animals were probably tree-dwelling. Their remains were originally assigned to the " Creodonta ", later the " Condylarthra ". The insect eater Saturninia from the group of Nyctitheriidae is also very rare, but with several mandibles, some of which are completely dentate . Rodents are rare and found only a few forms. Ailuravus was very tall, about three feet long, and resembled today's squirrels . Few bits of dentition come from the much smaller Masillamys , the Messel mouse named after the Messel Pit with a very long tail and a total length of 40 cm. The remains of the bats are also important, 25 of which are complete skeletons with parts of the wing skin. They can largely be assigned to the genera Matthesia and Cecilionycteris . They belong to the family of the Palaeochiropterygidae , whose representatives hunted with echolocation from 30 to 70 kHz due to the structure of the auricular ossicles .

X-ray image of Godinotia from the Geiseltal

Notable remains also come from the primates . The Adapidae , of which several genera occurred in the Geiseltal and which may have been the forerunners of today's lemurs , are particularly important here. Europolemur is handed down with several skulls and lower jaws . Godinotia is one of the few almost complete skeletons worldwide of an adaptive primate . This early primate, which was closely related to Darwinius known from the Messel mine , had a clearly short facial skull and large eye sockets, which indicate a nocturnal lifestyle. Nannopithex is very varied with several species, but it belongs to a more modern family of primates.

Lower jaw of Prodissopsalis from the Geiseltal

Rather predatory animals were the now extinct "Creodonta". These include above all the hyaenodonta with around 50 finds, including predominantly the lower jaw, but also some skulls, upper jaw fragments and isolated remains of the musculoskeletal system. These include Eurotherium , Matthodon , Prodissopsalis and Leonhardtina , the latter two being the most common and each comprising around a dozen fossils. Overall, all of the Creodont animals found in the Geiseltal were relatively small, so a complete Eurotherium skull was about 12 cm long. A crushed skull and a single posterior upper premolar represent the true predators and were originally classified as Miacis , but now classified as Quercygale .

Live reconstruction of Amphirhagatherium from the Geiseltal

The fossil material of the ungulates is comparatively extensive with around 170 objects found from around 60 individuals. The cloven-hoofed ungulates of the Geiseltal were all characterized by a very ancient physique with an arched back, very long tails and short front and long hind legs. They were consistently smaller than today's relatives and reached maximum piglet size . One of the most primitive cloven-hoofed ungulates was Diacodexis from the group of Diacodexeidae , although only a few bone fragments have been passed down. The Eurodexis from the closely related group of the Dichobunidae, evidenced by a crushed skull, is a little more developed . Messelobunodon and Aumelasia belong to its close relatives , both of which are also documented with few finds. The representatives of the somewhat more developed Choeropotamidae , which are closely related to the hippos and which were endemic in today's Europe, could be observed most frequently . An almost complete skeleton is available from Masillabune , while Hallebune is only represented with a few fragments of teeth. Several skeletal remains, including seven almost complete, can be assigned to Amphirhagatherium . This animal, around 70 cm long and weighing around 4 kg, was not only the most common, but also the largest cloven-hoofed animal in the Geiseltal and is widely distributed over the lower and middle coal. In addition, a few remains of other ungulates such as Haplobunodon or Rhagatherium are known.

Skeleton of Propalaeotherium from the Geiseltal, discovered in 1933 and one of the most famous finds

Skeleton of Lophiodon from the Geiseltal

The most extensive finds are available from the odd-toed ungulates . These too had an ancient physique with an arched back and four toes on the front and three on the hind feet, which today only occurs with the tapirs . More than 310 lower and 120 upper jaw remains including two complete skeletons come from the horse relatives of the Palaeotheriidae group . The well-known primeval horse Propalaeotherium , which is represented by several species, should be emphasized . A complete skeleton with a 56 cm long trunk, 20 cm long skull and shoulder height of 40 cm was discovered in 1933. Other genera that occur are Lophiotherium , Hallensia and Eurohippus . There are only a few teeth of the very rare Plagiolophus . With almost 180 individuals, Lophiodon is also very common , a tapir relative who, with a body length of 2.5 m and a shoulder height of 1 m, represents the largest representative of the mammals from the Geiseltal. 110 individuals were discovered on an area of ​​131 m² alone, probably the remains of a crocodile feeding ground. Fossil finds of Lophiodon are known from all fossil-bearing seams, with the genus going through a significant increase in body size from bottom to top. In addition, his relative Hyrachyus appeared less often and could be identified with about 75 remains of teeth and some parts of the body skeleton. Hyrachyus was more modern than Lophiodon and is at the base of the development of rhinos and tapirs.

Soft tissues, chemofossils, and food scraps

Fossilized milk sap tubes ("monkey hair") from the Geiseltal

Remains of the soft tissues have also been preserved in the lignite of the Geiseltal , which is extremely rare. Fossil soft tissues were first detected in the Geiseltal in 1934; they are among the first such finds from the Eocene . The discoveries only came with the development of the paint film method . Thus, among other things, the fine scale relief could be recognized in individual fish , for example in Thaumaturus , also in scale creepers and less often in crocodiles . The skin of numerous frogs could be examined, the individual layers of which, the epidermis and dermis , can be seen down to the individual cells . On some remains of birds feathers could be found, some of which were colored; The flying skin has been handed down from bats . In mammals , such as Amphirhagatherium and, more rarely, Propalaeotherium , parts of the hair coat have been detected. It was also possible to document muscles, cartilage and the like, right down to blood cells .

In addition, the original color of certain soft tissues, especially the skin, could be seen. The body of the fish Palaeoesox had a zebra pattern and a dark-colored back, while frogs had a greenish skin tone. In the case of insects , the color shades of the animals are preserved, in the case of plants the chlorophyll has survived. Such chemofossils also include “monkey hair”, fibrous structures of a light brown color that are flattened by storage in the brown coal and often occur in large quantities. They are fossilized milky sap tubes of rubber-producing woody plants from the dog-poison family , of which there are leaves of the genus Apocynophyllum from the Geiseltal. According to the recent genus Couma , the "monkey hair" is referred to as a form taxon but to Coumoxylon .

Other finds are above all the food remains of numerous animals, which were also discovered early, for example in 1935 in the case of the tapir relative Lophiodon as a greenish plant mass . They have also been found in other mammals such as the primeval horse Propalaeotherium and the arthropod Amphirhagatherium , as well as the ostrich-like bird Palaeotis . At least 100 copies of coprolites and additional fragments have also been documented. They are mostly in egg or sausage-like form with lengths of a few millimeters to a decimeter and sometimes contain remains of bones, claws or plants. Various reptiles and mammals can be assumed to be responsible. Some of the fossilized excrement residues also contain gastroliths , which may have come from crocodiles. Crocodiles also occasionally left bite marks on mammalian bones and turtle shells.

Dating

Stratigraphic position of the Geiseltal within the Eocene

The faunistic remains, especially the mammals, are important for the exact age classification of the lignite in the Geiseltal, which also enables a comparison with other sites and outcrops. This biostratigraphic age determination is largely based on the changes in the tooth morphology of certain mammalian groups, with which the temporal occurrence of extinct species and genera can be determined. The first vertebrate finds discovered at the beginning of the 20th century, tooth remains of the tapir relative Lophiodon , led to the classification of lignite in the geological epoch of the Middle Eocene . This also determined the more precise relative equivalent of lignite, which was previously only suspected. The Middle Eocene is dated to an age of 47.8 to 41.3 million years and consists of the lower stage Lutetium and the upper stage Bartonium . The exact age of the Geiseltal lignite can be determined relatively precisely from the occurrence of certain mammalian forms. As a result, the rich finds from the Lower Coal to the Upper Central Coal are placed in the Geiseltalium zone , a stage within the stratigraphy of European Land Mammal Ages (ELMA). The Geiseltalium serves as a reference for the Geiseltalium, and it also forms a central section of the Lutetium. The few finds of the upper coal are referred to a younger zone, the Robiacium . The beginning of the Geiseltalium goes hand in hand with the appearance of early forms of the primitive horse Propalaeotherium , but also of its relative Lophiotherium or the primate Europolemur , while the end is indicated by the first appearance of primates such as Adapis .

Absolute dating using radiometric measuring methods is not available from the Geiseltal. However, such were made in about the same old sites. Data, determined with potassium-argon dating , come from the important Messel mine in Hesse, which from a biostratigraphic point of view corresponds to the section of the lower coal of the Geiseltal, and resulted in an age of 47.8 million years. Since the basalt investigated comes from an area under the fossil-bearing lake sediments of the Messel Pit, the age value is to be regarded as the maximum age, so the finds there are somewhat younger ( terminus post quem ). The Eckfelder Maar in Rhineland-Palatinate is a biostratigraphic equivalent to the Upper Middle Coal. Data from pyroclasts obtained there using the same measurement method , also below the find layer, resulted in a value of 44.3 million years. This is also to be regarded as the lowest age. As a result, the age classification of the Geiseltalium, which today is assigned an age of 47.4 to 43.4 million years, and thus the finds from the Geiseltal can be regarded as quite safe.

Landscape reconstruction

The numerous plant and animal remains, but also the large amount of geological data, enable a fairly precise reconstruction of the former landscape. According to this, the Geiseltal in the Middle Eocene was a water-rich moorland that extended north-south over a length of four to five kilometers and which was close to the coast on a bay that penetrated far inland. This land cut, known as the Central German Estuary , which was at least temporarily exposed to the tides based on pollen finds of the palm genus Nypa from the Central Coal , formed numerous bays , especially in the middle section of the Eocene (more precisely in the Lutetium ), as well as local depressions and basins that gave rise to lignite promoted, such as the Helmstedt lignite district in the northwest or the lignite depots of Egeln and Edderitz further south. This branched system also led to the formation of marine , brackish to fluvial and limnic deposits (the main resources) as legacies of the estuary in the Geiseltal . The then subtropical climate contributed to the creation of numerous moors, ponds and ponds with rich vegetation on the edge of the estuary. The onset of coalification of the dead plant material resulted in the formation of mighty brown coal seams over a period of six to possibly eight million years . The area was bordered in the south by a shell limestone plateau with steep slopes sloping to the north. The plateau itself was partly karstified . The chemical weathering created lime water that penetrated the moorland and ensured the excellent preservation of the fossils.

Thick layer of leaves of Dryophyllum from the Geiseltal

The moor area was interspersed with numerous small ponds and ponds with a diameter of around eight to ten meters, which are indicated by collapse funnels and served as drinking places for fossil animals. Acrostichum , Myricaceae and Restionaceae plant communities grew in the adjacent bank area . In the wider area there were shrubbery and forest landscapes of palm-pine forests, interspersed with sequoias and other conifers and hardwoods, which were rich in herbs and light and had several levels of growth. These forests were criss-crossed by a network of meandering rivers, which periodically rose over their banks. To the south in the direction of the Muschelkalkzug these forests merged into a dense jungle of laurel plants . Due to the relative proximity to the coast, the altitude should not have been more than 50 m above sea level at that time. Overall, the climate was subtropical with frost-free and dry winters with an average temperature of at least 5 ° C and humid summers with a vegetation period of up to nine months and an average of 25 ° C in the warmest month, which was determined on the basis of the numerous fruits and seeds. The annual precipitation should have been around 2070 mm. Due to the clear temperature differences during the summer and winter months, the landscape was subject to an annual period of rainy and dry seasons, which can also be demonstrated, among other things, by tree rings and by a fine warvung of the brown coal. As a result, the fall of leaves can be seen as likely, so that the leaves formed a loose layer of litter on the ground. From the lower to the middle coal, however, an increasing dryness of the climate could be determined.

This diverse landscape was inhabited by numerous animals. Leaf- and fruit-eating mammals such as Lophiodon , Propalaeotherium and Amphirhagatherium lived mainly in the forests . The rich insect fauna was in turn the basis of nutrition for numerous other animals, such as frogs , newts and scalloped reptiles , but also leptictids , bats and some primates . The ponds and pools housed aquatic or amphibious animals. The numerous crocodile forms , which, like today, preferred a significantly warmer climate and thus also represent an important climate indicator, should be emphasized. The richness of the ecosystem and the long storage period of around 3 million years also reveal certain network of relationships that go beyond pure food chains. This can be seen, among other things, from Lophiodon and Propalaeotherium , which represent the two most common mammal forms and probably had a special ecological relationship to one another due to the use of the same food resources. But while Lophiodon increased in size over time (an average of 124 kg in the lower coal and 223 kg in the upper coal), Propalaeotherium lost weight (an average of 39 kg in the lower coal and 26 kg in the upper middle coal). Possibly this is an example of the gradual adaptation to different ecological niches in order to avoid too strong competition with one another.

Comparison with regionally and supra-regionally important sites

From the regional neighborhood of the Geiseltal valley, the same old lignite outcrops, for example from the Leipzig area (the Weißelster basin) or the Helmstedt area, are of particular importance. Although there are no vertebrate remains here, innumerable floristic finds are known. Macro remains in the form of cones of conifers and palm leaves occur in the opencast mines near Helmstedt , while numerous dicotyledon leaves are found in the Profen opencast mine . The general vegetation history determined on the basis of the microflora largely corresponds to that of the Geiseltal. Vertebrate sites of the same age are not known from the nearby region. With the finds from Walbeck in the north-west of Saxony-Anhalt, one of the most extensive mammal communities worldwide is known from the Middle Paleocene almost 60 million years ago. The fauna, comprising several thousand bones and tooth remains, differs from that of the Geiseltal through the dominance of primeval mammals from the groups of the Procreodi , " Condylarthra " or Leptictida , while representatives of more modern lines that still exist today, such as the primates , appear rarely or as with the Unpaired ungulates and ungulates are completely absent. Walbeck thus represents an important testimony to the early phase of the radiation of mammals shortly after the dinosaurs became extinct .

The Messel Pit in Hesse and the Eckfelder Maar in Rhineland-Palatinate are of outstanding importance in a national comparison . Both represent sites of discovery in former maars , with Messel being at about the same time as the lower coal of the Geiseltal, but Eckfeld is the upper middle coal. In addition to plant and invertebrate finds, a high number of vertebrate remains are known from both sites, which currently comprises around 130 taxa in Messel , while the number of finds from Eckefeld is comparatively lower. While the composition of the mammal fauna generally shows similarities, there are clear differences in the individual areas. In the Geiseltal and in Eckfeld, for example, rodents and bats are underrepresented, but they are more common and more diverse in Messel. On the other hand, Messel is characterized by a lower number of primate and cloven-hoofed forms, which in the Geiseltal and Eckfeld are in turn well and variedly documented, with marked deviations in the occurrence of different genera being reflected. Similar differences can also be worked out for individual mammal genera, for example Lophiodon from the group of odd ungulates, which is one of the dominant forms in the Geiseltal, but could only be detected in Messel with a young animal and individual tooth finds, in Eckfeld with a lower jaw and also few tooth remnants . What is remarkable in Eckfeld is the lack of ancient groups of mammals such as the " Creodonta " and "Condylarthra", which occur to a small extent at least in Messel and the Geiseltal. In addition, differences can also be shown in other groups of finds. The jewel beetles, with more than a quarter of all beetle finds, are relatively common in Geiseltal, whereas in Messel they are less than a tenth, but there is a generally higher variety of beetles overall. The fact that, among other things, only a few forms of jewel beetles occur at both sites at the same time indicates significant ecological differences, which are also reflected in the sometimes differing diversity of the most varied of plant and animal groups and shows that the individual fossil sites only represent a section of the represent the rich landscape of that time.

Research history

Scientific excavations

Johannes Walther , initiator of the scientific excavations in the Geiseltal

Although the mining of lignite in the Geiseltal has been proven to date back to 1698, the first fossils were discovered relatively late. The earliest fossil find dates back to 1908 and includes remains of the tapir relative Lophiodon , which was more or less accidentally picked up by a steiger in the Cecilie open-cast mine . Further finds were recovered in 1912 that include several remains of teeth from three individuals and belong to the same genus. In the following year, remains of turtles were observed for the first time in a plant-bearing coal layer, but some of the finds disintegrated after exposure. Some of the remaining fossils were handed over to the State Geological Institute in Berlin .

Further turtle finds in 1925 then led to systematic scientific excavations initiated by geologist Johannes Walther (1860–1937) and coordinated by the University of Halle . The native Englishman Ben Barnes took over the management on site. He mainly examined different areas in the Cecilie opencast mine . The aim was not only to record qualitatively complete pieces, but also to gain a quantitative overview of the fossil content of the lignite, whereby also smaller or poorly preserved objects were documented. Barnes excavations uncovered, among other things, the remains of snakes and turtles as well as the teeth and bones of various ungulates. The work resulted in a first more comprehensive scientific publication in 1927. After Walther left teaching, Johannes Weigelt (1890–1948) continued this. Ehrhard Voigt (1905–2004) developed the paint film method in the early 1930s to improve the preservation of fossils . A first high point was reached in 1933 with the discovery of a complete, 74 cm long skeleton of the ancient horse Propalaeotherium in the Cecilie open-cast mine, which was located in the center of a collapse funnel and from which numerous crocodile remains and partly complete lizard skeletons still come. In the same open-cast mine only one year later, the only significant site of the upper coal was examined with over 20 individuals of Lophiodon , including an almost complete skeleton. In the Cecilie opencast mine , scientific research came to a standstill in 1935 due to the exhaustion of coal supplies. Further excavations were then carried out in the Leonhardt opencast mine , among others , but came to a standstill in 1938. The outbreak of the Second World War in 1939 finally ended this first important period of research.

In 1949, the excavation activities were resumed and subsequently funded by the government of the GDR on a larger scale. In addition, numerous scientists from other nations were able to be involved in the evaluation of the finds. With the expansion of the open-cast mine, which reached its peak in the middle of the 20th century, numerous other sites were opened up, including in the Pfännerhall and Müchi mining fields (which included the former areas of Pauline , Elisabeth , Emma and Elise II of the western Geiseltal). The scientists discovered site XIV, one of the richest in fossils, and were able to identify a new site in the form of streams in addition to the types of sites already defined by Weigelt. The increased coal production meant that more excavation work was carried out in parallel with the mining, so that the 1960s and 1970s in particular represented a high point in the exploration of the Geiseltal. It was only when the coal reserves began to decline (the eastern and south-eastern Geiseltal had already been exhausted at the beginning of the 1970s and the abandoned open-cast mines were partially flooded) and the relocation of mining to the northern and western parts of the Geiseltal, where fossil conservation was less good , the scientific on-site investigations also declined and temporarily ended in 1985. During this research phase, more than 55 new sites were discovered, including 23 with vertebrate remains.

After the political change in the GDR in 1989, the situation changed fundamentally. After the production of lignite in the western Geiseltal was originally supposed to continue until 1998, however, due to changed market conditions, it was stopped in mid-1993 and the renaturation of the entire open-cast mining area began. As a result, the last investigations of a site in the southern Geiseltal were carried out from spring to autumn 1992, with employees of the Senckenberg Research Institute also being involved. In the following year, this last vertebrate site was flooded by rising groundwater. Between the years 2000 and 2003, the last field activities took place again together with the Senckenberg Research Institute in the western Geiseltal, which mainly concerned a coal seam over 20 m thick, which contained innumerable plant material up to 25 m long tree trunks. Due to the chemical properties of lignite in this area of ​​the Geiseltal, no vertebrate remains could be observed. In June 2003, the planned flooding of the western Geiseltal to Geiseltalsee began , which had reached its final water level in the spring of 2011, creating one of the largest artificial lakes in Central Europe. This finally ended the scientific activities on site.

Found presentation

Geiseltalmuseum , exhibition room

As early as 1934, only nine years after the excavation work began, the Geiseltal Museum was opened in the New Residence near Hallesches Dom in the Saalestadt Halle , which was built on behalf of Cardinal Albrecht II between 1531 and 1537 due to the immense increase in finds . The museum also served as a collection depot and exhibition, which was set up in the All Saints Chapel on an area of ​​267 m². The other rooms of the New Residence, on the other hand, were used by the Geological-Paleontological Institute of the Martin Luther University Halle-Wittenberg . The original horse skeleton from 1933, assigned to Propalaeotherium , served as the heraldic animal of the museum . The exhibition was interrupted shortly before the end of the Second World War in 1945 when the finds had to be relocated for security reasons.

In 1950 the exhibition reopened under the motto “Walk through Central Germany's geological history” - expanded by eight rooms and revised in 1954. As a result of a university reform at the end of the 1960s, the museum and collection were to be relocated, which the then director Horst Werner Matthes was able to avert. However, the new exhibition opened in 1950 had to be closed and reduced. In the years that followed, technical and financial bottlenecks meant that it was not possible to invest in a more modern exhibition or in repairing the building of the New Residence, which made it necessary to protect individual found objects from damage due to rainfalls or thaws. Only after 1989, with the political change in the GDR, did this change for the better. However, the structure of the New Residence remained in poor condition. When the current Institute for Geosciences moved to new and more modern premises on the new campus at Von-Seckendorf-Platz in 2004, only the Geiseltal Museum and its collection remained and celebrated its 70th anniversary there.

From the end of 2011 to May 2018 the museum was closed and the collection was not open to the public. The reopening took place as part of the Long Night of the Museums on May 5, 2018. In spring 2015, a special exhibition entitled “From the Dawn: Horse-Hunting Crocodiles and Giant Birds” in the Chernyshevsky House of the Leopoldina in Halle provided information about the latest research results the Geiseltal fossil deposit. Between November 2017 and May 2018, some important fossils from the Geiseltal were part of the special exhibition "Climate Forces - Driving Force of Evolution" at the State Museum for Prehistory in Halle. In 2012 the entire collection was given the status of “nationally valuable cultural asset” and is therefore under government protection.

literature

• Alexander K. Hastings, Meinolf Hellmund: From the dawn: Horse-hunting crocodiles and giant birds. Latest research results on the Eocene world of Germany approx. 45 million years ago. Halle (Saale), 2015, pp. 1–120.
• Meinolf Hellmund: Excursion: Former Geiseltalrevier, southwest of Halle (Saale). From the Vita of the Eocene Geiseltal. In: Jörg Erfurt, Lutz Christian Maul (Hrsg.): 34th meeting of the working group for vertebrate paleontology of the paleontological society March 16-18, 2007 in Freyburg / Unstrut. In: Hallesches Jahrbuch für Geoswissenschaften. Supplement 23, 2007, pp. 1-16.
• Günter Krumbiegel, Ludwig Rüffle, Hartmut Haubold: The Eocene Geiseltal: a Central European brown coal deposit and its flora and fauna. Ziemsen, Wittenberg 1983, pp. 1-227, OCLC 9998655 .

Individual evidence

1. ↑ Krumbiegel, Rüffle, Haubold 1983, pp. 7-14.
2. ↑ ^{a b c} Joachim Wirth, Rudolf Eichner, Andreas Schroeter: Revier Halle and Geiseltal. In: Gerhard H. Bachmann, Bodo-Carlo Ehling, Rudolf Eichner, Max Schwab (eds.): Geology of Saxony-Anhalt. Stuttgart 2008, pp. 491-493.
3. ↑ ^{a b c d e f g h i} Meinolf Hellmund: Excursion: Former Geiseltalrevier, southwest of Halle (Saale). From the Vita of the Eocene Geiseltal. In: Jörg Erfurt, Lutz Christian Maul (Hrsg.): 34th meeting of the working group for vertebrate paleontology of the paleontological society March 16-18, 2007 in Freyburg / Unstrut. (Hallesches Jahrbuch für Geoswissenschaften BH 23), 2007, pp. 1–16.
4. ^ ^{A b c} Karl-Heinz Radzinski, Bodo-Carlo Ehling, Reinhard Kunert, Gerhard Beutler: Southeastern Harz foreland. In: Gerhard H. Bachmann, Bodo-Carlo Ehling, Rudolf Eichner, Max Schwab (eds.): Geology of Saxony-Anhalt. Stuttgart 2008, pp. 458-471.
5. ↑ Krumbiegel, Rüffle, Haubold 1983, p. 23.
6. ↑ ^{a b} Matthias Thomae, Ivo Rappsilber: On the origin of the Geiseltalsenke. In: Harald Meller (Hrsg.): Elefantenreich - Eine Fossilwelt in Europa. Halle / Saale 2010, pp. 27–33.
7. ^ ^{A b} Matthias Thomae, Ivo Rappsilber: Contribution to the clarification of the storage conditions of the Quaternary in the Neumark-Nord opencast mine. In: Dietrich Mania et al. (Ed.): Neumark-Nord: An interglacial ecosystem of the Middle Palaeolithic people. (Publications of the State Museum for Prehistory, 62). Halle / Saale 2010, pp. 71–80.
8. ↑ Horst Blumenstengel, Wilfried Krutzsch: Tertiary. In: Gerhard H. Bachmann, Bodo-Carlo Ehling, Rudolf Eichner, Max Schwab (eds.): Geology of Saxony-Anhalt. Stuttgart 2008, pp. 267-292.
9. ↑ ^{a b} Hartmut Haubold, Matthias Thomae: Stratigraphic revision of the vertebrate discovery sites of the Geiseltal. In: Hallesches Jahrbuch für Geoswissenschaften. 15, 1990, pp. 3-20.
10. ^ Thomas Litt, Karl-Ernst Behre, Klaus-Dieter Meyer, Hans-Jürgen Stephan, Stefan Wansa: Stratigraphic terms for the Quaternary of the north German glaciation area. In: Ice Age and the Present (Quaternary Science Journal). 56, 2007, pp. 7-65 ( [1] ).
11. ↑ ^{a b c} Dietrich Mania: On the history of the Geiseltal in the Quaternary. In: Harald Meller (Hrsg.): Elefantenreich - Eine Fossilwelt in Europa. Halle / Saale 2010, pp. 34–38.
12. ↑ ^{a b c} Dietrich Mania: Quaternary research in the Neumark-Nord opencast mine, Geiseltal (Saxony-Anhalt) and its results so far. In: Dietrich Mania et al. (Ed.): Neumark-Nord: An interglacial ecosystem of the Middle Palaeolithic people. (Publications of the State Museum for Prehistory, 62). Halle / Saale 2010, pp. 11–69.
13. ↑ Lothar Eißmann: Mollisoldiapirismus. In: Journal of Applied Geology. 24, 1978, pp. 130-138.
14. ↑ Thomas Laurat, Enrico Brühl: On the status of the archaeological investigations in the Neumark-Nord opencast mine, Ldkr. Merseburg-Querfurt (Saxony-Anhalt) - preliminary report on the excavations 2003-2005. In: Annual publication for Central German prehistory. 90, 2006, pp. 9-69.
15. ↑ Thomas Litt: On the stratigraphic classification of Neumark-Nord on the basis of new pollen analysis findings. In: Altenburger scientific research. 7, 1994, pp. 328-333.
16. ↑ Jaqueline Strahl, Matthias R. Krbetschek, Joachim Luckert, Björn Machalett, Stefan Meng, Eric A. Oches, Ivo Rappsilber, Stefan Wansa, Ludwig Zöller: Geology, paleontology and geochronology of the Eem basin Neumark-Nord 2 and comparison with the basin Neumark-Nord 1 (Geiseltal, Saxony-Anhalt). In: Ice Age and the Present (Quaternary Science Journal). 59 (1/2), 2010, pp. 120-167.
17. ↑ Mark J. Sier, Wil Roebroeks, Corrie C. Bakels, Mark J. Dekkers, Enrico Brühl, Dimitri De Loecker, Sabine Gaudzinski-Windheuser, Norbert Hesse, Adam Jagich, Lutz Kindler, Wim J. Kuijper, Thomas Laurat, Herman J. Mücher, Kirsty EH Penkman, Daniel Richter, Douwe JJ van Hinsbergen: Direct terrestrial – marine correlation demonstrates surprisingly late onset of the last interglacial in central Europe. In: Quaternary Research. 75, 2011, pp. 213-218.
18. ↑ Daniel Richter, Matthias Krbetschek: Preliminary luminiscense dating results for two Middle Palaeolithic occupations at Neumark-Nord 2. In: Sabine Gaudzinski-Windheuser, wil roebroeks (ed.): Multidisciplinary studies of the Middle Palaeolithic record from Neumark-Nord (Germany) . (Publications of the State Museum for Prehistory, 69), Halle / Saale 2014, pp. 131–136.
19. ↑ Wolf-Dieter Heinrich: Remnants of small mammals from the Pleistocene basin deposits of Neumark-Nord 1. In: Dietrich Mania et al. (Ed.): Neumark-Nord: An interglacial ecosystem of the Middle Palaeolithic people. (Publications of the State Museum for Prehistory, 62). Halle / Saale 2010, pp. 327–337.
20. ↑ Dieter-Hans Mai, Jeanette Hoffmann: The vegetation of Neumark-Nord - A reconstruction based on carpological remains. In: H. Meller (Ed.): Elefantenreich - Eine Fossilwelt in Europa. Halle / Saale 2010, pp. 140–149.
21. ↑ Roland Fuhrmann: The ostracod fauna of the interglacial basins of Neumark-Nord (Geiseltal, Saxony-Anhalt) and their statement on the stratigraphic position. In: Mauritiana. 32, 2017, pp. 40-105 ( [2] ).
22. ↑ Roland Fuhrmann: Warthe cold period or Warthe stage - for the stratigraphic structure of the younger Quaternary. In: Mauritiana. 22, 2011, pp. 77-93 ( (PDF) ).
23. ↑ Dietrich Mania, Maria Seifert, Matthias Thomae: Late and post-glacial in the Geiseltal (middle Elbe-Saale region). In: Ice Age and the Present. 43, 1993, pp. 1-22.
24. ↑ Tatjana Böttger, Achim Hiller, Frank Wolfgang Junge, Thomas Litt, Dietrich Mania, Norbert Scheele: Late glacial stable isotope record, radiocarbon stratigraphy, pollen and mollusc analyzes from the Geiseltal area, Central Germany. In: Boreas. 27, 1998, pp. 88-100.
25. ↑ ^{a b c} Hartmut Haubold: Vertebrate excavation and research in the Geiseltaleocene. In: Hallesches Jahrbuch für Geoswissenschaften. B 17, 1995, pp. 1-18.
26. ↑ ^{a b} Hartmund Haubold: The reference fauna of the Geiseltalium, MP Levels 11 to 13 (Middle Eocene, Lutetian). In: Palaeovertebrata. 19 (3), 1989, pp. 81-93.
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145. ↑ Martin Luther University Halle-Wittenberg: Geiseltalmuseum closes - fossils from 2015 in the natural history university museum. Press release of the press office of the Martin Luther University Halle-Wittenberg, number 237/2011 of October 21, 2011 ( [4] ), last accessed on March 25, 2018.
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147. ^ Leopoldina: From the Dawn: Horse-Chasing Crocodiles and Giant Birds. Exhibition of the Martin Luther University Halle-Wittenberg at the Leopoldina March to May 2015 ( [6] ), last accessed on March 25, 2018.
148. ↑ State Museum for Prehistory in Halle: Climate violence - the driving force of evolution. Special exhibition of the State Museum for Prehistory in Halle November 2017 to May 2018 ( [7] ), last accessed on March 25, 2018.
149. ↑ Protection of cultural property in Germany: Nationally valuable cultural property. Country directories of nationally valuable cultural assets of the countries. Database ( [8] ), No. 14805, last accessed on April 11, 2019.

Web links

Commons : Geiseltal fossil deposit  - Collection of images, videos and audio files

• Geiseltalsammlung at the Martin Luther University Halle-Wittenberg
• Special exhibition: From the dawn: Horse-hunting crocodiles and giant birds

This article was added to the list of excellent articles on December 11, 2013 in this version .

Coordinates: 51 ° 18 '27.7 "  N , 11 ° 52' 9.1"  E