Gastornis

from Wikipedia, the free encyclopedia
Gastornis
Skeletal reconstruction of Gastornis

Skeletal reconstruction of Gastornis

Temporal occurrence
Seelandian ( Paleocene ) to Lutetian ( Eocene )
61.6 to 43.4 million years
Locations
  • Europe
  • North America (" Diatryma ")
Systematics
Birds (aves)
New-jawed birds (Neognathae)
Galloanserae
Gastornithiformes
Gastornithidae
Gastornis
Scientific name
Gastornis
Hébert , 1855

Gastornis is an extinct genus of large, flightless birds that are closely related to the goose birds . It waswidespreadfrom the Middle Paleocene to the Middle Eocene between 62 and 43 million years ago in both present-day Eurasia and North America . The first fossils of the genus Gastornis werediscoverednear Paris in1855and were first described in the same year. The oldest North American finds date from 1876 and were originally assigned to the genus Diatryma . For a long time, both genres were considered independent, for which a faulty reconstruction from the end of the 19th century was partly responsible. It was not until the early 1990s that it was recognized that Diatryma and Gastornis are closely related, and new bone finds from France finally led to the synonymisation of Diatryma with Gastornis .

For a long time, Gastornis was seen as an agile predator specialized in meat nutrition, which primarily hunted smaller mammals and, in connection with its size, represented a top predator of its time. The view went hand in hand with a skeleton structure similar to the South American "terror birds" ( Phorusrhacidae ), which was worked out on the basis of an almost complete skeleton find from Wyoming , discovered in 1916 . This similarity was partly based on incorrect assumptions about the length of individual bones in the foot skeleton. It was not until the 1970s that the image of the agile runner could be corrected with new foot bones found. According to this, Gastornis represented a rather slowly moving, ground-dwelling bird due to its physique. The diet was not clear for a long time. In addition to the specialization in meat food, a purely plant-based diet was discussed again and again, which resulted primarily from anatomical considerations such as the size of the animal and the structure of the beak. Several independent studies from 2013 confirmed the view of specialization in plant foods for the time being.

features

Habitus

Gastornis (artist's impression)

Gastornis was a very large and robustly built, flightless bird that reached a top height of 1.75 to a little over 2 m. European representatives were on average somewhat smaller than North American ones. The body weight for the early forms in Europe was estimated at around 100 kg, for later forms between 135 and 156 kg, making it one of the largest and heaviest birds known. Special features of the representatives of Gastornis were the large head with a powerful beak, the short but powerful neck and the massive legs, the lower sections of which were rather short. As with today's large flightless birds, the wings had greatly reduced bones in length.

Skull and beak

Skull of Gastornis

The skull was very large and measured 43 cm in a complete specimen, the mighty beak took 23 cm of it. This was also very high, a total of 16.5 cm, and heavily narrowed at the sides. The top of the beak had a clearly convex curvature, while the tip of the beak was not elongated like a hook. The latter feature in particular distinguishes Gastornis from the similarly built Phorusrhacidae ("terror birds"). The outer nostrils were about 5 cm in front of the orbit and near the lower edge of the beak. They were small and forward facing. Here, too, there are differences to the Phorusrhaciden, whose nostrils often start directly at the eye window. The orbit itself was surrounded by a strong and prominently raised bulge. The square leg , typical of birds , was characterized by its size, but overall it was rather short and stocky. The zygomatic arches also had a short structure and ran in an S-curve. In contrast to the massive beak, the entire rear skull, which began behind the eye windows, was only slightly extended.

The lower jaw was massive, up to 38 cm long and very high on the bone body with up to 10 cm. Both halves of the lower jaw were firmly fused together through the symphysis in the anterior area, the anterior end tapered to a point. The connection reached partly over a length of 18 cm and thus took up almost half of the total length of the lower jaw, which is unusual for birds.

Body skeleton

The spine is not fully known, but in general the vertebrae were characterized by their robustness and their short vertebral bodies. The neck was formed from 13 or 14 vertebrae. There were seven rib-bearing vertebrae on the back. The ribs that began there were thin and curved. The tail comprised ten or more vertebrae. The forelimbs were severely stunted. Typical of flightless birds was the obtuse angle between the shoulder blade and the raven bone , which reached 180 °, similar to the two-legged dinosaurs with shortened forelegs, but in contrast to the flightless birds, in which the angle is less than 90 °. The hind legs, on the other hand, were extremely strong. The thigh bone reached a length of 38 cm and was a good 10 cm wide at the lower joint end. The tibiotarsus measured almost two feet and had a straight shaft. The fibula, on the other hand, looked very graceful. With a length of around 25 cm, the tarsometatarsus was designed to be very short and rather wide . The legs ended in four-pointed feet, of which three rays protruded forwards (II to IV) and one (I) stood backwards. Of the three toes pointing forward, the middle (III) had the greatest length, which is different from the equally huge moas with three equally long rays. The shortest beam was the one pointing backwards. The terminal phalanges were only short in shape and triangular in cross-section. In the longitudinal view they were only slightly curved, which in turn distinguishes them from the Phorusrhaciden.

biogeography

Fossil finds

Skeleton reconstruction of Gastornis based on finds from the Geiseltal

Gastornis has been found in both Europe and North America . The European finds date from the Middle Paleocene to the Middle Eocene from 62 to about 41 million years ago. The oldest evidence includes the sparse remains of Walbeck in western Saxony-Anhalt , which date back to the Seelandium around 60 million years ago. Amongst them is a 7 cm long raven leg . The most extensive finds on the continent are known from the Geiseltal . They include more than three dozen objects, including mostly remains of the walking legs and the pelvis, but also wing bones and parts of the skull such as the lower jaw. They can be assigned to a total of nine individuals and are distributed over the Lower Coal to the Upper Central Coal of the site, thus dating to the Middle Eocene around 47 to 43 million years ago. The findings of the upper middle coal are also the youngest Gastornis -Funde at all. A singular find in the form of an approximately 30 cm long thigh bone from the Messel pit in Hesse , which was located in a rock nodule, is just as old as the Geiseltaler lower coal . It had already been found during the mining operation at the beginning of the 20th century, but could only be safely assigned in the 1960s. In contrast, numerous remains of the Mont-de-Berru near Reims in the eastern part of the Paris basin are known. They are a little younger than those of Walbeck and represent, among other things, numerous remains of the leg. A lower jaw from the same location is 31 cm long and is significantly smaller than the later representative. The southernmost European remains also include some leg bones, vertebrae and an 18 cm long and 17 cm high remains of an upper beak from Saint-Papoul in the Aude department in southern France . In addition, fossils from Gastornis were found in London and Belgium .

Skull and lower jaw of the first almost complete skeleton from Gastornis

The known North American finds can all be assigned to the Lower Eocene 56 to 49 million years ago and are distributed over 50 sites. One of the few complete skeletons that has been reconstructed is up to 2.1 m high. This comes from the Bighorn Basin in the US state of Wyoming . It was discovered at the beginning of the 20th century and is the result of numerous previous, in-depth investigations, in which some leg and foot bones had already come to light. A larger collection from the Willwood formation comes from the same basin , which also includes remains of skulls and legs as well as vertebral finds. Other finds were also found in New Mexico . A tarsometatarsus is particularly important here, which led to the establishment of the genus Diatryma in 1876 . Few bone remnants could also be described from the Lower Ocene Margaret Formation on Ellesmere Island in the arctic north of Canada . These represent the most northerly known finds of Gastornis at all. Only a few remains are known from Asia that also have a Lower Oocene age. This includes a lower end of a large tibiotarsus from the Yuhuangding formation in the Chinese province of Henan . This was described in 1980 as the genus Zhongyuanus , which is closely related to Gastornis , but a revision in 2013 revealed no significant morphological differences to Gastornis .

Soft tissues, eggs and trace fossils

Apart from fossil bone fragments, only a few remains of the soft tissue are known. As early as the 1920s, feather finds from Loan Creek in the western US state of Colorado were described, which were a good 20 cm long and came from the Green River Formation . After closer examination, these turned out to be the remains of plant fibers. Actual feathers in the form of, among other things, a 24 cm long specimen, on the other hand, came to light in the Fossil Butte Member , also part of the Green River Formation. But since missing more fossil remains, they can only partially because of their size Gastornis be assigned.

From Provence and Languedoc in southeastern and southern France , numerous fragmented eggs were found in deposits of the Upper Paleocene ( Thanetian ) and Lower Eocene ( Sparnacian ), the discovery of which dates back to the 1950s. The eggshells were up to 3.1 mm thick. A few, partly completely preserved eggs reached dimensions of 24 × 15 cm, which makes them larger than those of the African ostrich ( Struthio ) but smaller than those of the Malagasy elephant birds ( Aepyornis ). Some other eggs even had a diameter of up to 40 cm. Based on the curvature of large shell fragments, a volume of up to 1300 cm³ could be calculated for individual eggs; the original weight was probably 1.4 kg. Since the eggshells are of different sizes and structures, they are interpreted as the remains of various bird species, which, since no further fossil material is available, are assigned to the Oogenus Ornitholithus , whereby Ornitholithus arcuatus represents the larger species and could correspond to Gastornis . The closest site with remains of Gastornis is only a few dozen kilometers away at Saint-Papoul. However, it is quite possible that other early birds such as the ostrich-like Palaeotis , a portion of the eggs could have laid. Further finds of eggshells that are assigned to the same oogenus come from the Tremp Formation in northeastern Spain.

Trace fossils are also rare finds . In the Chuckanut Formation in northwest Washington state , step seals of a large bird with three forward-pointing toes were found in Lower Oocene sandstone layers . The largest seals are 28.5 cm long and 24.5 cm wide. Due to the size of the footprints, Gastornis can be regarded as the cause. Since there are no other fossils, they are assigned to the Ichnospecies Rivavipes giganteus . A similar but singular trace had already been reported from King County of the same state, which belongs to the Middle to Upper Eocene and is therefore outside the temporal range of Gastornis in North America. Today this trace is considered a pseudofossil. Fossil traces of large birds were also known from Europe, from plaster deposits of Montmorency north of Paris, and were associated with Gastornis . However, these belong to the Upper Eocene, for which there is no evidence of this bird genus in Europe.

Paleobiology

Drawing reconstruction of Diatryma

Diet

The diet of Gastornis was and is the subject of scientific controversy. Very early on, scientists concluded from the mighty and very powerful beak that Gastornis must have been a carnivore. This developed convergent to the South American, now also extinct Phorusrhacidae ("terror birds"), which among other things have a similar type of beak. As a result, both lines emerged independently of one another after the extinction of the dinosaurs around 65 million years ago and occupied the niche that became free for large predators. Investigations into the biomechanics of the lower jaw in connection with the massive symphysis and the powerful upper jaw showed that the beak and the temporomandibular joints were designed to develop a high bite force, especially in the back of the beak. The symphysis withstood large, both transverse and vertical loads. The resulting force, it was calculated, was sufficient to crack every known nut . The beak was therefore considered too well equipped for a purely plant-based diet, even if its structure is similar to that of parrots and other seed and nut eaters. According to this view, it was used to catch prey, to mangle carrion and to break bones or crustaceans . Smaller mammals such as Propalaeotherium , which occurs frequently in the Geiseltal , as well as smaller reptiles and molluscs served as the basis of food . Gastornis acted as a strong "bush breaker" when catching prey. As the top predator of its time, Gastornis would only have competed with the large, mostly water-dwelling crocodiles .

A predominantly plant-based diet was adopted as an alternative scenario as early as the 1970s, although this view gained a new impetus in the early 1990s. It was argued that the upper beak lacks the hook-shaped end that is typical for birds of prey - only a juvenile skeleton from the Bighorn Basin in Wyoming has a slightly downward-pointing middle jawbone . The feet did not have the characteristic raptor claws, which are also among the phorusrhacidae are detected ( "terror birds") and its absence is also in the fossil preserved Gastornis associated footprints can observe. According to this view, Gastornis fed on numerous plants of the dense tropical rainforests , which he bit or cut with his beak. The Takahe ( Porphyrio ), which is still alive today, is also regarded as a species of bird that is analogous in appearance and possibly in diet to Gastornis . This flightless bird, which is widespread in New Zealand today , has a strong, high beak, a short neck and also short leg bones, but only weighs a maximum of 3 kg and is a relative of the railing . A completely plant-based diet is little known in today's airworthy birds, since the energy required for flight has to be provided directly from the food. Such a diet does occur in large flightless birds. Since leaves are a rather low-energy food that is digested for a long time, Gastornis should have spent a lot of time eating a plant -based diet that is clearly rich in leaves. The switch to a purely plant-based diet for Gastornis was seen in connection with the enormous increase in body size. An analysis of calcium isotopes in the fossil bones of Gastornis finds from the Geiseltal in 2013 revealed isotope ratios similar to those of herbivorous mammals. These in turn differ significantly from those of the carnivorous mammals and the equally nourishing dinosaurs such as Tyrannosaurus , since animals with such a diet have a significantly higher proportion of volatile isotopes ( 42 Ca). Studies of Gastornis remains from several sites in France came to comparable results . These were compared with various carnivorous and herbivorous birds and mammals, and new biomechanical investigations of the beak were carried out. It turned out that the adductor mandibulae in particular was developed with a similarly strong development as in today's seed-cracking forms of Darwin's finches , while it is less prominent in predatory birds of prey. The muscle is connected to the intake of food and serves to close the beak and thus to break up the ingested food. Gastornis is also assumed to bite hard seeds. It is now more likely that the representatives of the genus Gastornis were herbivores.

Locomotion

The legs are similar to those of today's African ostrich ( Struthio ). As with this, a large part of the muscle mass of the legs is also concentrated directly below the body in Gastornis , which can be recognized by the rather short and very compact thigh bone . As a result, the legs act like a pendulum under the torso and enable movement. As a fast runner, the ostrich has a long and slender tarsometatarsus and two toe rays protruding forward on the feet. Other live today ground-dwelling birds, including cassowaries ( Casuarus ) and rheas ( Rhea ), have also next to a long tarsometatarsus on feet with three forward-facing rays. This reduction in the number of toe rays compared to four in many airworthy birds is a functional adaptation to fast running in open landscapes and reduces the frictional resistance with the ground. Gastornis, on the other hand, has a comparatively short and wide tarsometatarsus. The leg also ends in four-pointed feet, one of which points backwards ( anisodactyl ). This combination of features is to be regarded as very primitive, also in comparison to other ratites living today. Due to the short bones of the foot and the fourth toe pointing backwards, only a low running speed is reconstructed for Gastornis . Since the predominant habitat of the bird species is dense tropical and subtropical rainforest, a slow walk is assumed, which may have been interrupted by short, faster gaits. The slightly curved claws of the feet also represent an adaptation to stronger ground activities and slow walking and are less suitable for a quick hunt for prey. It is unclear whether the back short toe functionally supported the foot in locomotion. The step seals from the Chuckanut formation do not have a rear, fourth toe print, so that this toe could possibly have been too much reduced.

Systematics

Phylogenetic position of Gastornis according to Agnolin 2007
  Aves  

 Phorusrhacidae


  Galloanseres  

 Chicken birds  (Galliformes)


   

 Gastornis


  Goose birds (Anseriformes)  

 Brontornithidae ( Brontornis et al.)


   

 Dromornithidae


  Anseres  

 Ducks i. w. S. (anatoidea)


   

 Cleft foot geese (Anseranatidae)


   

 Defense birds (Anhimidae)









Template: Klade / Maintenance / Style

Gastornis is a genus of the Gastornithidae family . These represent large flightless birds, which are characterized by a strong, laterally narrowed beak, which has a convex curved upper side ( culmen ), but in contrast to the similarly built Phorusrhacidae does not have a hook-like tip. The origin of the Gastornithidae is not fully understood. Maybe they can with large birds from the Upper Cretaceous be associated as with Gargantuavis , using a 6.5 cm long Synsacrums from near Fox Amphous in the French department of Var in Provence were first detected for this time period. Other finds, such as a pelvis, a femur and several vertebrae, also come from southern France. These fossil remains indicate a bird the size of an ostrich, possibly weighing up to 140 kg, and have similarities to those of Gastornis , but these late Cretaceous birds are most likely not the direct ancestors. The features of the limb bones and the temporomandibular joint make it clear, however, that Gastornis and its relatives summarized in the order Gastornithiformes are related to the goose birds (Anseriformes) and the chicken birds (Galliformes). Today they form the sister group to the geese birds.

In the course of the history of research, numerous types of gas tornis have been described;

  • G. geiselensis Fischer , 1976
  • G. gigantaeus Cope , 1876
  • G. parisiensis Hébert , 1855
  • G. russelli Martin , 1992
  • G. sarasini Schaub , 1929
  • G. xichuanensis Hou , 1980

G. russelli is the oldest and smallest species in phylogeny , which only reached half the size of today's ostrich. It is a sister form to the other types of Gastornis . Other species described, such as G. steini , G. edwardsi and G. klaasseni , are no longer valid today. For North America, in addition to G. gigantaeus , G. regens is also recognized as an independent species, which differs slightly in the proportions of the toe joints. Other researchers consider G. geiselensis to be synonymous with G. sarasini , but this is only partially recognized. In general, a new revision of the genre is called for.

Tribal history

Since the oldest records of Gastornis come from today's Europe, the genus and family is believed to have originated here. However, the origin has not yet been clarified. During the Paleocene , today's Europe represented an island with endemic fauna, which found numerous ecological niches here after the mass extinction on the Cretaceous-Paleogene border , to which a large part of the land vertebrates over 25 kg body weight fell victim. At the time of the earliest records of Gastornis around 62 million years ago, the largest mammals on this island only reached a weight of around 45 kg. It is possible that the genus developed into a giant form under such an isolated island ecosystem, similar to what has been handed down from later times with the Aepyornithidae in Madagascar , which grew into the largest indigenous group of animals there, exceeding all existing mammals in size. Only in the transition to the Lower Eocene were connections to North America (via Greenland ), which also resulted in a considerable exchange of fauna. On the one hand, this led to Gastornis being replaced as the largest inhabitant by some large mammals such as Coryphodon from the Pantodonta group ; on the other hand, it also enabled him to reach new regions. The most likely route is the one over Greenland, which is also shown by the sparse finds from Ellesmere Island . The genus reached Asia either via North America or possibly directly via the Turgai Strait , which separated the continent from Europe. However, large herbivorous mammals already lived on both land masses, which in the case of the pantodonts weighed up to 600 kg. It is therefore acceptable that Gastornis died out in competition with these in North America and Asia at the end of the Lower Eocene. The genus persisted successfully in Europe until the end of the Middle Eocene, around 43 million years ago.

Gastornis and Diatryma - On the research history of a bird genus

Reconstruction of Gastornis after Lemoine 1881
Reconstruction of Diatryma after Matthew and Granger 1917

Research into the genus Gastornis dates back to the middle of the 19th century. In 1855, the French physicist Gaston Planté (1834–1889), who later invented the lead-acid battery , discovered the first bones of a giant bird in deposits from the Upper Paleocene and Lower Eocene , the "Conglomérat de Meudon" in a western suburb of Paris . which included a femur and a tibiotarsus . In the same year these were described by Edmond Hébert as belonging to the newly created genus Gastornis , which at that time was one of the oldest known bird genera. The name Gastornis is derived from the first name Plantés, Gaston, and the Greek name ὄρνις ( órnis ) for "bird". Only a short time later, a few more finds came to light near Passy, ​​also near Paris. The systematic position of Gastornis was completely unclear at that time. Hébert himself concluded (1855) that Gastornis was too heavy to fly and, like Alphonse Milne-Edwards (1867) , put the genus close to the duck birds (Anatidae), Édouard Armand Lartet (1855) thought of a relationship with the plover-like (Charadriiformes) ), Achille Valenciennes (1855) even saw similarities with albatrosses (Diomedeidae) and Charles Lucien Jules Laurent Bonaparte (1856) considered Gastornis to be a relative of the large Malagasy bird Aepyornis . Richard Owen, in turn, gave a first precise description of the tibiotarsus in 1859 and thought Gastornis was a terrestrial bird. Very extensive material was discovered after a period of around 20 years in the Lower Palaeocene "Conglomérat de Cernay" near Reims , which was the oldest known fossil site of the Tertiary in Europe at that time. These find material prompted Victor Lemoine (1823–1911) to make a skeleton reconstruction in 1881, which differed considerably from the actual appearance of Gastornis known today . So he created a large, graceful looking bird with a long neck, short wings and long legs with a long and slender tarsometatarsus. The paddle-like feet also suggested swimming ability. Lemoine was inspired by recently discovered birds such as Archeopteryx or Hersperornis for his reconstruction . Over the next few decades, this was decisive for the appearance of Gastornis . In the following time only a few other finds were made on Gastornis , such as the fossil remains of Croydon in England and Walbeck in Germany.

Using a large tarsometatarsus from the Lower Eocene in the US state of New Mexico , Edward Drinker Cope (1840-1897) described the genus Diatryma in 1876 , the name referring to a foramen penetrating the upper end of the bone shaft, an opening in the bone. Cope recognized similarities to the European gas tornis , but favored a generic name of its own. However, anatomical comparisons between the two species of birds were hardly possible in the following years, as only sparse fossil remains were known from North America. A toe bone from New Jersey referred Othniel Charles Marsh to Barornis in 1894 , who was later reunited with Diatryma . The situation did not change until 1916, when an almost complete skeleton was found in the Bighorn Basin of Wyoming , which William Diller Matthew (1871-1930) and Walter W. Granger (1872-1941) described extensively the following year. Their reconstruction of the skeleton turned out to be completely different from Lemoines, which was illustrated by the stocky, robust body and the huge head with a powerful beak. This made a comparison with the European Gastornis relatively difficult for the two researchers , and they cautiously expressed doubts as to whether all the bones in Lemoine's reconstruction belonged to Gastornis . Furthermore, they certified both bird representatives an independent genus status, a view that was later followed by numerous scientists. During the reconstruction of the Diatryma skeleton, Matthew and Granger reconstructed the tarsometatarsus due to the partly incomplete foot skeleton, possibly influenced by the long legs of today's ratites, as a result of which not only the mighty beak but also the limbs similar to those of the Phorusrhacidae ("Terrorvögel “) Worked. This group of birds had come into the public eye since the 1880s with intensive research in Patagonia . Mainly in the Santa Cruz formation numerous "terror birds" like Phorusrhacos , Psilopterus and Patagornis were discovered. These were large, flightless birds with long limbs, massive bills with a raptor-like, pointed end and feet with strong, curved claws, which characterized the animals as fast and effective predators. Both researchers advocated a separation of the Diatryma and the Phorusrhaciden, but also adopted a comparable way of life due to the almost identical size and the similarities in physique including the long lower limbs. In the period that followed, new European finds, for example from the Geiseltal and the Messel pit in Germany or from Lyon in France, were assigned to the genus Diatryma .

Live reconstruction from 1917

Although Matthew and Granger, in their first publication of the skeleton of Diatryma , expressed little about its way of life in addition to its basic outward correspondence with the "terror birds", partly caused by the incorrect reconstruction of a long tarsometatarsus, the point of view came for the first time in the mid-1920s about a carnal diet for this giant bird based on small reptiles and mammals. The extremely popular idea of ​​a hunt for the small primitive horses at the beginning of their tribal history , such as Hyracotherium or arthropods such as Diacodexis, established itself in the 1930s, largely supported by Alfred Romer . Even the discovery of a partial skeleton of a still juvenile Diatryma -like bird in 1928 in the Bighorn Basin of Wyoming with a nearly complete foot and a short and wide tarsometatarsus instead of the long narrow one, hardly influenced this idea (the partial skeleton was described as Omorhamphus , now a synonym for Gastornis ). Numerous researchers took the view of a fast-running, hunting giant bird in the Eocene, for example George Gaylord Simpson in 1950 in his comparison of Diatryma with the South American "terror birds" and the European Gastornis according to Lemoine. The view was also widespread in Europe, for example for the Diatryma finds from the Geiseltal, where the propalaeotherium found here was assumed to be the bird's prey . It was Karlheinz Fischer , who in 1978 for the first time demonstrated the correct proportions in the limbs of Diatryma based on complete finds of the tarsometatarsus from the Geiseltal compared to other leg bones . The tarsometatarsus reached around 24 to 25 cm in length, significantly different from the 38 cm projected by Matthew and Granger, and took up almost 21% of the leg length, making the foot significantly shorter than previously assumed. With this, Diatryma turned out not to be a fast running bird, but a mostly slow one.

Until the late 1980s, the two bird genera Gastornis and Diatryma were assigned to different families, the former to the Gastornithidae and the latter to the Diatrymidae. The realization that both species of birds were much more similar only emerged in the early 1990s. During a revision of the skeletal reconstruction of Lemoine and the inclusion of new finds in 1992, LD Martin realized that the reconstruction was based only to a small extent on fossil remains from birds, namely only on a vertebra and parts of the treadmill and some foot bones, the much larger one On the other hand, part of it came from fish and reptiles , which gave rise to the primeval shape of Gastornis . Martin also established morphological similarities between Gastornis and Diatryma and referred both to the Gastornithidae family. New discoveries from Reims, such as an upper end of a tibiotarsus, which had not yet been described by Gastornis , but had already been found several times by Diatryma , raised the question in 1997 whether the two genera were not identical. Only a few years later, in 2002, gastornis and diatryma were formally synonymous , which was confirmed in 2008 by the discovery of another tibiotarsus from Saint-Papoul . Here was Éric Buffetaut this Fund to type species G. parisiensis provided but noted at the same time both similarities to comparable bones of G. geiselensis , originally as Diatryma had been described, as well as to similar finds from North America. The individual, existing differences are seen as so small that Diatryma is now synonymous with Gastornis .

literature

  • Allison V. Andors: Diatryma among the Dinosaurs. Natural History 1995 (6), pp. 68-72
  • Eric Buffetaut and Delphine Angst: "Terror cranes" or peaceful plant eaters: changing interpretations of the palaeobiology of gastornithid birds. Revue de Paléobiologie 32 (2), 2013, pp. 413-422
  • Eric Buffetaut and Delphine Angst: Stratigraphic distribution of large flightless birds in the Palaeogene of Europe and its palaeobiological and palaeogeographical implications. Earth Science Reviews 32 (2), 2014, pp. 394-408
  • Meinolf Hellmund: Reappraisal of the bone inventory of Gastornis geiselensis (Fischer, 1978) from the Eocene “Geiseltal Fossillagerstätte” (Saxony-Anhalt, Germany). New yearbook for geology and palaeontology treatises 269 (2), 2013, pp. 203–220

Individual evidence

  1. ↑ a b c Karlheinz Fischer: New remains of the giant ratite Diatryma from the Eocene of the Geiseltal near Halle (GDR). Communications Zoologisches Museum Berlin, Suppl., 54, Annalen für Ornithologie 2, 1978, pp. 133-144.
  2. ↑ a b c d e f g h i Meinolf Hellmund: Reappraisal of the bone inventory of Gastornis geiselensis (Fischer, 1978) from the Eocene “Geiseltal Fossillagerstätte” (Saxony-Anhalt, Germany). New yearbook for geology and palaeontology treatises 269 (2), 2013, pp. 203–220.
  3. ↑ a b c d Gerald Mayr: Gastornithidae. In: Gerald Mayr: Paleogene Fossil Birds. Springer-Verlag, Berlin and Heidelberg, 2009, pp. 44–47.
  4. ↑ a b c d e f Eric Buffetaut and Delphine Angst: Stratigraphic distribution of large flightless birds in the Palaeogene of Europe and its palaeobiological and palaeogeographical implications. Earth Science Reviews 32 (2), 2014, pp. 394-408.
  5. ↑ a b c d e f g h William Diller Matthew and Walter W. Granger: The skeleton of Diatryma, a gigantic bird from the lower Eocene of Wyoming. Bulletins of the American Museum Natural History, 37, 1917, pp. 307-326.
  6. ↑ a b c d e Lawrence M. Witmer and Kenneth D. Rose: Biomechanics of the jaw apparatus of the gigantic Eocene bird Diatryma: implications for diet and mode of life. Paleobiology 17 (2), 1991, pp. 95-120.
  7. ↑ a b Delphine Angst and Eric Buffetaut: The first mandible of Gastornis Hébert, 1855 (Aves, Gastornithidae) from the Thanetian (Paleocene) of Mont-de-Berru (France). Revue de Paléobiologie, Genève 138, 2013, pp. 423–432.
  8. ^ A b c d e Allison V. Andors: Diatryma among the Dinosaurs. Natural History 1995 (6), pp. 68-72.
  9. ↑ Gerald Mayr: The birds from the Paleocene fissure filling of Walbeck (Germany). Journal of Vertebrate Paleontology 27 (2), 2007, pp. 394-408.
  10. ^ A b Karl-Heinz Fischer: The giant flightless bird Diatryma from the Eocene brown coal of the Geiseltal. Hallesches Jahrbuch für Mitteldeutsche Erdgeschichte 4, 1962, pp. 26–33.
  11. ↑ Dietrich E. Berg: Evidence of the giant flightless bird Diatryma in the Eocene from Messel near Darmstadt / Hessen. Notes of the Hessian State Office for Soil Research 93, 1965, pp. 68–72.
  12. ↑ Norbert Micklich: ratites. In: Gabrielle Gruberg and Norbert Micklich (eds.): Messel - Treasures of primeval times. Stuttgart, 2007, pp. 85-93.
  13. ↑ a b c d Eric Buffetaut: New remains of the giant bird Gastornis from the Upper Paleocene of the eastern Paris Basin and the relationships between Gastornis and Diatrjtma. New yearbook for geology and palaontology monthly books 1997 (3), pp. 179–190.
  14. ^ Estelle Bourdon, Cecilie Mourer-Chauvire and Yves Laurent: The birds (Aves) from the Early Eocene of La Borie, southern France. Acta Palaeontologia Polonica 61 (1), 2016, pp. 175–190 doi: 10.4202 / app.00083.2014 .
  15. ^ A b c Eric Buffetaut, First evidence of the giant bird Gastornis from southern Europe: a tibiotarsus from the Lower Eocene of Saint-Papoul (Aude, southern France). Oryctos, 7, 2008, pp. 75-82.
  16. ^ A b Edward Drinker Cope: On a gigantic bird from the Eocene of New Mexico. Proceedings of the Academy of Natural Sciences of Philadelphia 28, 1876, pp. 10-11.
  17. ^ RM West and Mary R. Dawson: Vertebrale Paleontology and the Cenozoic History of the North Atlantic Region. Polarforschung 48 (1/2), 1978, pp. 103-119.
  18. ↑ Jaelyn J. Eberle and David R. Greenwood: Life at the top of the greenhouse Eocene world - A review of the Eocene flora and vertebrate fauna from Canada's High Arctic. Geological Society of America Bulletin; January / February 124 (1/2), 2012, pp. 3–23.
  19. ↑ Hou Lian-hai: New form of the Gastornithidae from the Lower Eocene of the Xichuan, Honan. Vertebrata Palasiatica 18 (2), 1980, pp. 111-115.
  20. ↑ a b Eric Buffetaut: The giant bird Gastornis in Asia: A revision of Zhongyuanus xichuanensis Hou, 1980, from the Early Eocene of China. Paleontological Journal 47 (11), 2013, pp. 1302-1307.
  21. ^ TDA Cockerell: The supposed plumage of the Eocene bird Diatryma. American Museum Novitates 62, 1923, pp. 1-4.
  22. ↑ Alexander Wetmore: The Supposed Plumage of the Eocene Diatryma. Auk 47 (4), 1930, pp. 579-580.
  23. ^ Lance Grande: The lost world of Fossil Lake. Snapshot from deep time. University of Chicago Press, Chicago and London, 2013, pp. 1-425 (pp. 216 and 225).
  24. ↑ a b c George E. Mustoe, David S. Tucker, Keith L. Kemplin: Giant Eocene bird footprints from Northwest Washington, USA. Palaeontology 55 (6), 2012, pp. 1293-1305 doi: 10.1111 / j.1475-4983.2012.01195.x .
  25. ^ A b William J. Sinclair: Omorhamphus, a New Flightless Bird from the Lower Eocene of Wyoming. Proceedings of the American Philosophical Society 67 (1), 1928, pp. 51-65.
  26. ^ Max Planck Society: Harmless Terrorvogel. The prehistoric bird Gastornis was probably not a bird of prey, but a herbivore. MPG of August 30, 2013 ( [1] ).
  27. ↑ Thomas Tütken, P. Held and SJG Galer: Isotopes in vertebrate bioapatite: proxies for climate, pCO2 and diet. Miner Mag 77, 2013, p. 2368 (Conference abstracts) ( [2] ).
  28. ↑ Alexander K. Hastings and 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.
  29. ↑ a b Delphine Angst, C. Lécuyer, R. Amiot, Eric Buffetaut, F. Fourel, F. Martineau, S. Legendre, A. Abourachid and A. Herrel: Isotopic and anatomical evidence of an herbivorous diet in the Early Tertiary giant bird Gastornis. Implications for the structure of Paleocene terrestrial ecosystems. Natural Sciences 101, 2014, pp. 313–322.
  30. ↑ Federico L. Agnolin: Brontornis burmeisteri Moreno & Mercerat, un Anseriformes (Aves) gigante del Mioceno Medio de Patagonia, Argentina. Revista del Museo Argentino de Ciencias Naturales, Nueva Series 9 (1), 2007, pp. 15-25 ( [3] ).
  31. ↑ Eric Buffetaut, Jean Le Loeuff, Patrick Mechin and Annie Mechin-Salessy: A large French Cretaceous bird. Nature 377, 1995, p. 110.
  32. ↑ Eric Buffetaut and Jean Le Loeuff: Gargantuavis philoinos: Giant bird or giant pterosaur? Annales de Paléontologie 96 (2010), pp. 135–141.
  33. ↑ Eric Buffetaut: Les oiseaux fossiles du Crétacé Supérieur de L'Herault. Bulletin de la Societe d'Etude des Sciences Naturelles de Béziers 66, 2012, pp. 34-39.
  34. ↑ Eric Buffetaut: The unfinished story of the Early Tertiary giant bird Gastornis. DGF On Line Series 1, 1997 ( [4] ).
  35. ↑ a b c d Eric Buffetaut and Delphine Angst: "Terror cranes" or peaceful plant eaters: changing interpretations of the palaeobiology of gastornithid birds. Revue de Paléobiologie 32 (2), 2013, pp. 413-422.
  36. ^ A b Eric Buffetaut: L'oiseau géant Gastornis: interprétation, reconstitution et vulgarisation de fossiles inhabituels dans la France du XIXe siècle. Bulletin de la Société géologique de France 168, 1997, pp. 805-811.
  37. ↑ Eric Buffetaut: Tertiary ground birds from Patagonia (Argentina) in the Tournouër collection of the Muséum National d'Histoire Naturelle, Paris. Bulletin de la Société Géologique de France 185 (3), 2014, pp. 207-214.
  38. ↑ Federico J. Degrange, Jorge I. Noriega and Juan I. Areta: Diversity and paleobiology of the Santacrucian birds. In: Sergio F. Vizcaíno, Richard F. Kay and M. Susana Bargo (eds.): Early Miocene paleobiology in Patagonia: High-latitude paleocommunities of the Santa Cruz Formation. Cambridge University Press, New York, 2012, pp. 138-155.
  39. ↑ George Gaylord Simpson: Are Nonflying Wings Functionless? Science 112, 1950, p. 342.

Web links

Commons : Gastornis  - collection of images, videos and audio files
Wiktionary: Gastornis  - explanations of meanings, word origins, synonyms, translations