Plateosaurus

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Plateosaurus
Skeleton reconstruction of Plateosaurus engelhardti from Trossingen (copy number AMNH 6810) in the American Museum of Natural History in New York

Skeleton reconstruction of Plateosaurus engelhardti from Trossingen (copy number AMNH 6810) in the American Museum of Natural History in New York

Temporal occurrence
Upper Triassic (middle Norium to Rhaetium )
217.4 to 201.3 million years
Locations
  • Europe
Systematics
Lizard dinosaur (Saurischia)
Sauropodomorpha
"Prosauropoda"
Plateosauridae
Plateosaurus
Scientific name
Plateosaurus
von Meyer , 1837

Plateosaurus ("Breitweg lizard") is a basal (original) genus of the sauropodomorphic dinosaur . It is the type and eponymous genus of the Plateosauridae family . Finds of these animals come from the Upper Triassic (middle Norium to Rhaetian ), especially Central Europe , and are therefore around 217 to 201 million years old.

Two species of Plateosaurus are currently recognized: the type P. engelhardti from the late Norium and Rhaetian and the geologically somewhat older species P. gracilis from the early Norium. However, the systematics and taxonomy of the plateosaurid dinosaurs are still controversial, and there is a large number of generic and species synonyms.

The first find of a Plateosaurus was made in 1834 by Johann Friedrich Engelhardt in the Heroldsberg region not far from Nuremberg . He handed the material over to the Frankfurt vertebrate paleontologist Hermann von Meyer for processing. He described it in 1837 under the name Plateosaurus engelhardti . This made Plateosaurus the fifth scientifically described dinosaur, even if the genus Richard Owen was not subsequently used to define the Dinosauria , since the material known at the time was quite incomplete and difficult to recognize as a dinosaur according to the state of knowledge at the time. Today Plateosaurus is one of the best known dinosaurs, of which well over 100 partially complete skeletons have been found in very good condition.

Plateosaurus was a bipedal (two-legged) herbivore with a small skull perched on a long, flexible neck, sharp but stocky teeth, strong hind legs, and a strong grasping hand with an enlarged thumb claw that may have been used in food procurement or defensive behavior. Unusual for a dinosaur is the pronounced developmental plasticity of Plateosaurus : Adult individuals were not all more or less the same size, but between 4.8 and 10 m long and weighed between 600 kg and 4 tons. The lifespan of most of the individuals studied so far ranged from 12 to 20 years.

Despite the abundant finds and the good preservation of the material, the appearance of Plateosaurus was controversial for a long time, which led to partially contradicting reconstructions. Some researchers drew up hypotheses on locomotion, nutrition, paleobiology and ecology as well as the taphonomy of the finds, which, according to the current state of research, are in clear contradiction to the geological and paleontological findings that can be derived from the skeletal anatomy and the conditions of the find places. Since 1980 the taxonomy and taphonomy, since 2000 the biomechanics and other aspects of the paleobiology of Plateosaurus have been re-examined, which fundamentally changed the overall picture of the genus.

Because of its frequency in southern Germany, the paleontologist Friedrich August Quenstedt gave Plateosaurus the nickname "Swabian Lindworm".

description

A large specimen of P. engelhardti compared to a human

Plateosaurus belongs to a group of early herbivorous lizard basin dinosaurs that were traditionally referred to as prosauropods . Today, most researchers speak of "basal sauropodomorphs" instead of "prosauropods", ie sauropodomorphs that are below the sauropods in the family tree . Plateosaurus shows a construction plan typical of two-legged herbivores: a small skull sits on a long, flexible neck made up of ten cervical vertebrae, the body is compact and merges into a long, flexible tail made up of over 40 vertebrae. The arms of Plateosaurus are among the shortest that "prosauropods" have, but they were strong and the hand was adapted to gripping large objects. The shoulder girdle was narrow (often incorrectly reconstructed in skeletal montages and drawings), with the collarbones touching in the middle , as they are also known from other “prosauropods”. The legs were long and held vertically under the body, and the foot was digitigrad . Plateosaurus was therefore a toe walker and adapted to brisk two-legged running.

P. engelhardti skull cast in the Royal Ontario Museum

Plateosaurus' skull was small and narrow. The snout was occupied by many small, leaf-shaped teeth, five or six of which were in the premaxillary (intermaxillary bone), 24 to 30 in the maxillary (upper jawbone) and between 21 and 28 in the lower jaw. The corrugated, wide, leaf-shaped tooth crowns were suitable for crushing plant material. It is likely that Plateosaurus lived entirely on plants. The eyes were directed sideways, not forwards, so that there was good all-round vision, but not stereoscopic vision. In some finds, sclerotic circles under the eyes are preserved. Such rings made of ossified plates protect the eyeball from injury.

As is common for dinosaurs, the rump ribs of Plateosaurus were two-headed, that is, they forked at their upper end into an upper and a lower branch, each with a joint head (capitulum or tuberculum). The joint heads together with the corresponding joint surfaces (diaposphysis or parapophysis) of the respective vertebra form a hinge joint with moderate leeway . The interaction of all these joints with the respiratory muscles made it possible for the rib cage to expand and narrow again in the rhythm of the breath. With the help of a computer- modeled skeleton, taking into account the natural position of each vertebra and the resulting alignment of the axes of rotation of the two articulating ribs, a tidal volume of approx. 20 l for a specimen with a body weight of approx. 690 kg could be estimated, which is a value of 29 ml per kilogram of body weight. This latter value is typical for many birds, for example geese, and significantly higher than the average value for mammals. From this it can be concluded that Plateosaurus presumably had a bird-like lung with unidirectional air flow and ventilation through air sacs , although Plateosaurus did not show any postcranial pneumatization of the skeleton (openings and cavities that indicate the presence of air sacs in the bones). Together with evidence from the structure and growth of the bones, this indicates a warm-bloodedness of Plateosaurus .

The type species of Plateosaurus is P. engelhardti . Adult individuals of this species reached a body length between 4.8 and 10 meters and a body weight of 600 kg up to 4 tons. The second, older species P. gracilis (formerly Sellosaurus gracilis ) was somewhat smaller and reached body lengths of 4 to 5 meters. There is no reliable knowledge about the skull of this species, since the affiliation of a very well preserved skull (copy number GPIT 18318a) in the collection of the Institute for Geosciences Tübingen to P. gracilis is questionable.

Discovery and History

The chemistry professor Johann Friedrich Philipp Engelhardt discovered some vertebrae and leg bones near Heroldsberg near Nuremberg in 1834 . He left this to Hermann von Meyer , who described it in 1837 as the new genus Plateosaurus with the species name engelhardti . Since then, remains of well over 100 individuals of Plateosaurus have been found.

In total, Plateosaurus material has been found at over 50 sites in Germany , mainly along the Neckar and Pegnitz rivers , as well as in Switzerland and France. Three sites are of particular importance because a particularly large amount of particularly well-preserved material was found here. Between 1910 and 1930, between 39 and 50 skeletons were found during excavations in a clay pit in Halberstadt in Saxony-Anhalt , most of which belong to Plateosaurus , but also to Liliensternus and Halticosaurus . Some of the plateosaur material was placed by Otto Jaekel on P. longiceps , a species that is now considered to be the younger synonym of P. engelhardti and therefore invalid. Most of the material went to the Museum für Naturkunde in Berlin , where large parts were destroyed in the Second World War. The site in Halberstadt is now built over with a residential area.

P. engelhardti copy number MSF 23 in the Frick dinosaur museum , the most complete Plateosaurus skeleton from Frick to date .

At the second rich site of Plateosaurus in Germany, a quarry in Trossingen , between the Black Forest and the Swabian Alb, children discovered bones at the beginning of the 20th century and handed them over to their teacher. This notified Eberhard Fraas , curator at the Stuttgart Natural History Collection (today State Museum for Natural History Stuttgart ). The site was made accessible in three excavations between 1911 and 1932. During excavation campaigns led by Fraas (1911-1912), Friedrich von Huene (1921-23), and finally Reinhold Seemann (1932), a total of 35 complete or largely complete skeletons of Plateosaurus were found, as well as parts from a further 70 individuals. A new excavation began in 2007 (as of October 2010).

The Plateosaurus fossils in the clay pit of Tonwerke Keller AG in Frick (Switzerland) were first noticed in 1976. The bones of this site were mostly severely deformed during the compaction and solidification of the clays during the diagenesis . Nevertheless, Frick offers skeletons that are comparable to those of Trossingen and Halberstadt in terms of completeness and posture. In 2015 an excavation team in Frick uncovered an eight-meter-long skeleton of a Plateosaurus; it is the largest dinosaur skeleton ever found in Switzerland.

During an oil exploration well in the Snorre oil field in the northern North Sea, a bone was drilled from 2,651 m below sea level in 1997, which the workers initially believed to be a plant fossil. However, the bone was identified in 2003 as a fragment of a Plateosaurus leg bone . Other finds have also been made on mainland Greenland.

Systematic classification and type material

As early as the first mention in 1837, von Meyer postulated a close relationship between Plateosaurus and the " dinosaur " genera Iguanodon and Megalosaurus described from England . In 1845 he coined the group name "Pachypodes" for Plateosaurus , Iguanodon , Megalosaurus and Hylaeosaurus , which fell due to the priority rule in synonymy with the name " Dinosauria " coined in 1842 by Owen .

Plateosaurus is the type genus of the Plateosauridae family, to which it has given its name. This was first set up in 1895 by Othniel Charles Marsh within the Theropoda and moved in 1926 from Huene to the Prosauropoda ; an assignment that was accepted by most of the subsequent editors. For a long time the family only included Plateosaurus and its synonyms (including Sellosaurus ), until 2004 a membership of Unaysaurus was suggested.

Plateosaurus is also the first scientifically described "prosauropod". The taxonomy of the "Prosauropoda" is controversial in the scientific literature, and it is now doubted by many researchers that they are a monophyletic group. Instead, they probably represent a series of branches from the stem line of the sauropods, which is why the term is used in quotation marks. A current study by Adam Yates finds Plateosaurus as a sister taxon to Unaysaurus , both together as Plateosauridae as a sister group to Ruehleia , and together with this in the Plateosauria as a sister group to a taxon that includes Riojasaurus , Massospondylus and the Sauropoda .

 Sauropodomorpha  

Saturnalia


   

Thecodontosaurus


   

Pantydraco


   

Efraasia


   

Plateosauravus


  Plateosauria  

Ruehleia


  Plateosauridae  

Unaysaurus


   

Plateosaurus



   

Riojasauridae


   

Massospondylidae


   

Jingshanosaurus


   

Anchisauria (including sauropoda )


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(The term "Prosauropoda" is mostly used today for all taxa from Efraasia to Sauropoda, but there is no clear agreement with some taxa whether they are sauropods or more highly developed "prosauropods". The term "basal sauropodomorpha" is also often used , which, however, does not find general acceptance because of the partly strongly derived characteristics of e.g. Plateosaurus . Also within the family tree, strongly different relationships are suggested. The above family tree is therefore only to be seen as an example of possible relationships.)

The Plateosaurus engelhardti type series consisted of "approximately 45 bones", of which almost half have been lost. The remaining material is kept at the Institute for Paleontology at the University of Erlangen-Nuremberg. From this series Markus Moser chose an incomplete sacrum as the lectotype . The exact type locality is not known, but Moser came to the conclusion, based on the old literature and the bone coloring and preservation, that the material comes from Buchenbühl, about 2 km south of Heroldsberg near Nuremberg in Bavaria .

The holotype of Plateosaurus gracilis , an incomplete skeleton without a head from the Stuttgart district of Heslach , is kept at the State Museum of Natural History in Stuttgart .

etymology

The derivation of the name "Plateosaurus" can not be clarified properly. As explained in detail by Markus Moser, the first description by von Meyer does not contain any information. A number of interpretations have been suggested, the first of which was by Agassiz. This gave ancient Greek platy (sic) / πλάτη (paddle, oar; Agassiz translated this into Latin pala = spade), as well as sauros / σαῦρος (lizard, lizard). He consequently changed the name to Platysaurus , which he probably derived from the Greek platys / πλατύς (broad, flat, broad-shouldered). This name is a younger and therefore invalid synonym. Later authors copied this derivation, so that Plateosaurus is often translated as "broad lizard" or "flat lizard". It is often claimed that platys / πλατύς should refer to the laterally flattened teeth of Plateosaurus . However, this is not possible because there were no teeth at all when it was first described. Moser therefore suggests ancient Greek plateia / πλατεία (broad way) as a probable strain , which fits better with the strain of Plateosaurus , which is clearly "plate" - and not "platy". Therefore Plateosaurus should be translated as "broad-path lizard".

Species of Plateosaurus

Valid types

Live reconstruction of P. gracilis , earlier than Sellosaurus known

The history of the taxonomy of Plateosaurus is complex and confusing. As of 2009, only two species are recognized as valid, the type species P. engelhardti and the somewhat older species P. gracilis , which was previously listed in an independent genus as Sellosaurus gracilis . Peter Galton showed that all skull material from Trossingen, Halberstadt and Frick belongs to one species. Markus Moser's detailed investigation of almost all plateosaurid material from Germany and Switzerland showed that everything up to now belongs to Plateosaurus and most of the material from the Keuper belonging to other plateosaurid genera belongs to the same species as the type material (ie to P. engelhardti ). Moser questioned the independence of Sellosaurus as a genus, but did not comment on whether this material is an independent species in the Plateosaurus genus . Adam Yates of the University of the Witwatersrand stated that this material is indeed a second, older species of Plateosaurus , P. gracilis . Von Huene suggested this as early as 1926.

Invalid types

All species of Plateosaurus except P. gracilis have proven to be younger synonyms of the type species or invalid names. Von Huene created a species or even genus for almost every fairly complete skeleton, a total of three species from Pachysaurus and seven from Plateosaurus for the Trossinger finds, as well as one species from Gresslyosaurus and eight from Plateosaurus from the Halberstadt material. Later he synonymized many of these species, but like Jaekel remained convinced that more than one genus and more than one species of Plateosaurus occurred at both sites. Systematic studies by Galton drastically reduced the number of genera and species considered valid. Galton initially synonymized all skull material, but described differences between the syntypes of P. engelhardti and the Trossinger material, which he compared to P. longiceps . He recognized P. trossingensis , P. fraasianus and P. integer as synonymous with P. longiceps . However, Markus Moser showed that P. longiceps itself is a younger synonym for P. engelhardti . In addition, a number of species existed in other genera of material belonging to P. engelhardti , including Dimodosaurus poligniensis , Gresslyosaurus robustus , Gresslyosaurus torgeri , Pachysaurus ajax , Pachysaurus giganteus , Pachysaurus magnus, and Pachysaurus wetzelianus .

However, a number of “prosauropod” finds from the marl marl are stored in museum collections, mostly listed as Plateosaurus in the catalog, which do not belong to the type species and possibly also not to the genus Plateosaurus . Some of this material cannot be used diagnostically, others are recognized as not belonging, but have never been described and named in detail.

Taphonomy

The taphonomy of the three large Plateosaurus discovery sites Trossingen, Halberstadt (both D) and Frick (CH) is unusual in various respects: Almost monospecific accumulations were found on all three, which means that almost all finds belong to the same species. However, lost theropod teeth were unearthed at all three sites, as was Proganochely's early tortoise . Complete and almost complete skeletons, as well as partial skeletons and individual bones, were found at all sites. The partial skeletons usually consist of hind legs, the hips and the whole or parts of the tail, while partial front bodies and necks are rare. All finds come from fully grown or at least almost adult animals; Young animals or even hatchlings were never found. Those finds that are complete or consist of hind legs plus other remains are almost always "correct", ie with the belly down, like the turtles. In addition, they are usually well articulated, and the rear legs are positioned three-dimensionally in a folded position, so that the feet are often significantly lower in the sediment than the hips.

Earlier interpretations

In the first publication about the Plateosaurus finds from Trossingen, Fraas suggested that the animals got stuck in the mud because only such an embedding situation could explain the preservation of the only known fully articulated skeleton at the time. Jaekel similarly interpreted the Halberstadt finds as animals that waded too deep into swamps and got stuck there and drowned. In Jaekel's opinion, partial skeletons were washed into the site by water, and were in clear contradiction to the catastrophic embedding of a herd. Von Huene, on the other hand, interpreted the sediments as aeolian , carried by the wind in a desert, where the weakest individuals, for the most part subadult (not fully grown), fell victim to the harsh conditions and sank into the mud of ephemeral waterholes. Von Huene justified his point of view with the fact that the high degree of completeness excludes transport and saw partial skeletons and isolated bones as a result of weathering and trampling by other animals. Seemann developed another scenario in which herds of plateosaurs gathered at large waterholes, with some herd members being pushed into the water. Lighter animals were released, heavier ones got stuck and died.

Another point of view, suggested by Weishampel almost half a century later, sees the finds in the lower layers of Trossingen as a herd that perished in a mud flow, while the skeletons of the upper layers were collected over a longer period of time. Weishampel explained the unusual monospecific accumulation with the fact that Plateosaurus was very common during this time. This theory was incorrectly attributed to Seemann in a popular science publication by the Institute and Museum for Geology and Paleontology (now the Institute for Geosciences) of the Eberhard Karls University of Tübingen and has since become the standard explanation on most websites, in children's books and other popular representations. Reiber proposed a more complicated scenario in which the animals died of thirst and the carcasses were later washed up by streams of mud.

Today's interpretation

A detailed re-examination of the taphonomy by Martin Sander showed that the “sunk in the mud” hypothesis proposed by Fraas for the first time is most likely: Animals above a certain weight sank into the mud, which was further liquefied by the kicking during their attempts at liberation . The Fraas-Sander scenario is the only one that conclusively explains all taphonomic observations. The completeness of the individual finds was not influenced by the transport, which can be seen from the fact that there are no signs of such, but by the extent to which scavengers have eaten on the carcasses. Plateosaurus juveniles and other herbivores were too easy to sink in or were able to free themselves, and are therefore not represented among the fossilized animals in Trossingen. Similarly, theropods that ate from the dead plateosaurs did not get stuck in the mud because their total weight was lower and was distributed over a proportionally larger footprint. There are no signs of the occurrence of Plateosaurus in herds (and none against it) or an accumulation (“flushing”) caused by a single event of animals that previously died occasionally elsewhere.

Paleobiology

Posture and locomotion

Cast of a P. engelhardti skeleton in the bipedal posture, which is now regarded as correct, in the Museo di Storia Naturale in Milan

Over time, almost every conceivable posture for Plateosaurus has been suggested in the specialist literature . For the animals he dug up in Trossingen, Von Huene assumed digitigrade bipedes with hind legs standing under the body (i.e. vertical), whereby the trunk should be erect at least when running fast. In contrast to this, the editor of the Halberstadt material, Otto Jaekel , initially concluded that it was a lizard-like locomotion, i.e. four-legged , plantigrades running in a straddling gait with strong lateral flexion of the body. Only a year later, however, Jaekel favored a clumsy, kangaroo-like hopscotch, a change of heart for which he was mocked by the zoologist Gustav Tornier, who viewed the shape of the joint surfaces in the hip as typically reptilian. Eberhard Fraas, who led the first excavations in Trossingen, also spoke out in favor of a reptile-like attitude. Another publication on this topic comes from Müller-Stoll, who listed a number of features that are necessary for a parasagittal (vertical view from the front) leg posture, but Plateosaurus is said to be missing, so that only a crawl is possible. However, these characteristics are very well present in Plateosaurus .

From 1980, a better understanding of the biomechanics of dinosaurs in general and in particular studies of the resistance to bending in the back and the structure of the pelvis of Plateosaurus by Andreas Christian and Holger Preuschoft led to the fact that a parasagittal, toe-walking stance and a more or less horizontal position of the Back generally accepted. Many researchers were of the opinion that Plateosaurus could move both biped (fast) and quadruped (slow), while Peter Wellnhofer, because of a strong downward curvature of the tail, concluded that bipedal movement was impossible. However, Moser showed that the tail was actually straight.

This almost universal view, according to which Plateosaurus represented a transition between the original two-legged dinosaurs and the obligate quadruped (exclusively four-legged) sauropods , was refuted in 2007 by a detailed study in which Bonnan and Senter showed that Plateosaurus did not have the ability to close its hand pronate (turn palm down). The pronated position of some skeletal structures in museums is created by an anatomically impossible exchange of the positions of the radius and ulna (spoke and ulna) in the elbow. This means that Plateosaurus was obligatorily biped (i.e., walked exclusively on two legs). Further indicators of purely bipedal locomotion are the large difference in leg length (the rear leg is more than twice as long as the front leg), the severely restricted range of motion of the front leg, and the position of the center of gravity above the feet.

Plateosaurus exhibits a number of adaptations to fast running, including a relatively long lower leg, an elongated metatarsus, and a digitigrade foot position. In contrast to mammals that are adapted to running, the lever arms of the leg-extending muscles are short, especially in the ankle, where there is no backward-facing process on the calcaneus (heel bone). This means that, unlike mammals , Plateosaurus presumably did not use fast gaits where there is a phase of flight (i.e., no foot is in contact with the ground for a short period of time). So Plateosaurus couldn't run. Instead, Plateosaurus must have achieved high speeds through high step frequencies with small step lengths, which were achieved by vigorously pulling the barely bent leg forward and backward. This emphasis on pulling back, not stretching, the leg is typical of non-avian dinosaurs.

nutrition

Skull of P. engelhardti in the Natural History Museum in Nuremberg

A number of important features on the skull of the original Sauropodomorpha such as Plateosaurus , such as the jaw joint, are more similar to herbivorous reptiles than carnivorous, and the tooth shape resembles that of modern herbivorous or omnivorous iguanas . The greatest width of the tooth crown is larger than that of the root, which leads to a cutting edge like that of today's omnivorous or herbivorous lizards. The corrugated, wide, leaf-shaped tooth crowns were suitable for crushing plant material. Due to its low position, the jaw joint offered the jaw-closing muscles a good lever arm, so that Plateosaurus had a powerful bite. In summary, therefore, it seems likely that Plateosaurus lived exclusively on plants.

Barrett suggested that original sauropodomorph dinosaurs supplemented their plant-based diets by grabbing small prey or consuming carrion, a speculation that is neither supported nor disproved by the fossil record.

So far no fossil of Plateosaurus with gastroliths (stomach stones) is known. The widespread view that almost all large dinosaurs, including Plateosaurus , used stomach stones for digestion because of their inability to chew their food, was confirmed in a study of the abundance, volume and surface structure of fossil gastrolites and those of birds and Alligators refuted. Apart from psittacosaurs, in which stomach stones were probably present as a parallel readjustment, the use of stomach stones as a digestive aid seems to have originated in the trunk line of the birds.

Growth, metabolism and lifespan

Similar to almost all other non-avian dinosaurs studied to date, Plateosaurus grew in a pattern that differs from that of mammals and avian dinosaurs. The closely related sauropods , which showed a growth pattern typical of dinosaurs, grew very quickly at first and continued their growth at a somewhat reduced rate after sexual maturity. However, the growth of the sauropods was determinate (limited) - the animals reached a stage in which they hardly grew any further. Mammals also grow very quickly, but their sexual maturity usually more or less coincides with the stopping of growth. The final size is fairly constant in both groups. Today's lizards show a sauropod-like growth pattern, with initially faster growth, then a reduction in the rate from around sexual maturity, and only minimal growth in old age. However, their initial rate is significantly lower than that of mammals, birds, and dinosaurs. In addition, it is subject to strong fluctuations, so that individuals of the same age can reach significantly different sizes and the final size achieved also varies greatly. In animals living today, this growth pattern is associated with behavior-related thermoregulation and a low metabolic rate ( poikilothermia and ectothermia ) and is called developmental plasticity .

Plateosaurus followed a growth curve similar to that of sauropods, but exhibited a variable rate of growth and final size as in today's lizards and snakes, arguably in response to environmental variables such as food supply. Some individuals were fully grown with a body length of only 4.8 meters, while others reached 10 meters in length. However, the cell structure of the bones indicates rapid growth, as is known from sauropods and mammals, which indicates endothermia . Thus Plateosaurus represents an early stage in the development of endothermia, in which it was decoupled from developmental plasticity. This hypothesis is based on a detailed study of long bone histology by Martin Sander and Nicole Klein. The probably bird-like lungs, ventilated by air sacs, which can be deduced from the breathing volume, also speaks for an endothermia of Plateosaurus .

By means of bone histology , the age of an individual can be estimated. Similar to the annual rings of trees, growth marks in the bones are viewed as an expression of different growth rates over the course of a year. The number of growth marks thus provides clues for the minimum age of the respective individual. However, with increasing age, more and more bone substance is reabsorbed ("dissolved"), whereby older growth marks are lost, so that a number of years that is difficult to estimate precisely must be added. In the case of long bones , for example, the thickest still visible growth ring is used to deduce the maximum number of growth marks that have been absorbed from the diameter of the medullary cavity . This method is likely to overestimate the age of the animal a little.

Sander and Klein found out in this way that some individuals of Plateosaurus were fully grown by at least 12 years, while others grew slowly by at least 20 years. A specimen must therefore have grown relatively quickly even when it is at least 18 years old. Most of the animals examined in this regard were aged between 12 and 20 years at the time of death. The oldest individual was around 27 years old. It can be assumed, however, that Plateosaurus could definitely reach an even higher age, since the fossilized animals in Trossingen and Frick, which were the subject of this analysis, did not die of old age, but had an accident in a swamp. Because there are no animals under 4.8 meters in length, it is not possible to create a complete growth series of Plateosaurus or to estimate the growth rates in the first ten years of life.

Web links

Commons : Plateosaurus  - album with pictures, videos and audio files

Individual evidence

  1. ^ Fabien Knoll: Review of the tetrapod fauna of the "Lower Stormberg Group" of the main Karoo Basin (southern Africa): implication for the age of the Lower Elliot Formation. In: Bulletin de la Société Géologique de France. Vol. 175, No. 1, 2004, ISSN  0037-9409 , pp. 73-83, doi : 10.2113 / 175.1.73 .
  2. ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , pp. 166-168, online .
  3. ↑ a b c Friedrich Frh. Von Huene : The fossil reptile order Saurischia, its development and history (= monographs on geology and palaeontology. Series 1, issue 4, ZDB -ID 634428-8 ). Part 1. Borntraeger, Leipzig 1932.
  4. ↑ a b c d e f g h Otto Jaekel : The vertebrates. An overview of the fossil and living forms. Borntraeger, Berlin 1911.
  5. ↑ a b c d e f g h i j k l m n o p q Markus Moser: Plateosaurus engelhardti Meyer, 1837 (Dinosauria: Sauropodomorpha) from the Feuerletten (Mittelkeuper; Upper Triassic) of Bavaria. = Plateosaurus engelhardti Meyer, 1837 (Dinosauria: Sauropodomorpha) from the Feuerletten (Middle Keuper; Upper Triassic) of Bavaria (= Zitteliana. Series B: Treatises of the Bavarian State Collection for Paleontology and Geology. Vol. 24, ISSN  1612-4138 ). Bavarian State Collection for Paleontology and Geology, Munich 2003, (At the same time: Munich, Ludwig Maximilians University, dissertation, 2005).
  6. ↑ a b c d e f g h i j k l m n Friedrich von Huene: Complete osteology of a plateosaurid from the Swabian Keuper (= Geological and palaeontological treatises. NF Vol. 15, No. 2, ZDB -ID 501422-0 ) . Fischer, Jena 1926.
  7. ↑ a b c d e f g h Heinrich Mallison: The digital Plateosaurus II: An assessment of the range of motion of the limbs and vertebral column and of previous reconstructions using a digital skeletal mount. In: Acta Palaeontologica Polonica. Vol. 55, No. 3, 2010, ISSN  0567-7920 , pp. 433-458, doi : 10.4202 / app.2009.0075 .
  8. ^ Adam M. Yates, Cecilio C. Vasconcelos: Furcula-like clavicles in the prosauropod dinosaur Massospondylus. In: Journal of Vertebrate Paleontology. Vol. 25, No. 2, 2005, ISSN  0272-4634 , pp. 466-468, doi : 10.1671 / 0272-4634 (2005) 025 [0466: FCITPD] 2.0.CO; 2 .
  9. ^ A b c Andreas Christian, Dorothee Koberg, Holger Preuschoft: Shape of the pelvis and posture of the hindlimbs in Plateosaurus. In: Paleontological Journal. Vol. 70, No. 3/4, 1996, ISSN  0031-0220 , pp. 591-601, doi : 10.1007 / BF02988095 .
  10. ↑ a b c d e f g Heinrich Mallison: The Digital Plateosaurus I: Body Mass, Mass Distribution, and Posture Assessed by Using CAD and CAE on a Digitally Mounted Complete Skeleton. In: Palaeontologia Electronica. Vol. 13, No. 2, 2010, ISSN  1094-8074 , p. 8A, online .
  11. ↑ a b c d e f g h i j k Peter M. Galton : Cranial anatomy of the prosauropod dinosaur Plateosaurus from the Knollenmergel (Middle Keuper, Upper Triassic) of Germany. I. Two complete skulls from Trossingen / Württ. With comments on the diet. In: Geologica et Palaeontologica. Vol. 18, 1984, ISSN  0072-1018 , pp. 139-171.
  12. ↑ Peter B. Frappell, Dave S. Hinds, Dona F. Boggs: Scaling of Respiratory Variables and the Breathing Pattern in Birds: An Allometric and Phylogenetic Approach. In: Physiological and Biochemical Zoology. Vol. 74, No. 1, 2001, ISSN  1522-2152 , pp. 75-89, doi : 10.1086 / 319300 .
  13. ^ Mathew Wedel: What pneumaticity tells us about 'prosauropods', and vice versa. In: Paul M. Barrett , David J. Batten (eds.): Evolution and palaeobiology of early sauropodomorph dinosaurs (= Special Papers in Palaeontology. Vol. 77). The Palaeontological Association, London 2007, ISBN 978-1-4051-6933-2 , pp. 207-22, digitized version (PDF; 1.15 MB) .
  14. ↑ a b c d e f g h i j k l m n o P. Martin Sander : The norian Plateosaurus bonebeds of central Europe and their taphonomy. In: Palaeogeography, Palaeoclimatology, Palaeoecology. Vol. 93, No. 3/4, 1992, ISSN  0031-0182 , pp. 255-299, doi : 10.1016 / 0031-0182 (92) 90100-J .
  15. ^ A b c d e P. Martin Sander, Nicole Klein: Developmental Plasticity in the Life History of a Prosauropod Dinosaur. In: Science . Vol. 310, No. 5755, 2005, pp. 1800-1802, doi : 10.1126 / science.1120125 .
  16. ↑ Steven F. Perry, Thomas Breuer, Nadine Pajor: Structure and function of the sauropod respiratory system. In: Nicole Klein, Kristian Remes, Carole T. Gee, P. Martin Sander (eds.): Biology of the Sauropod Dinosaurs. Understanding the Life of Giants. Indiana University Press, Bloomington IN et al. 2011, ISBN 978-0-253-35508-9 , pp. 83-93.
  17. ^ A b c d Hermann von Meyer : Communication to Prof. Bronn (Plateosaurus engelhardti). In: New yearbook for mineralogy, geognosy, geology and petrefacts. Born 1837, ZDB -ID 123936-3 , p. 316, digitized .
  18. ↑ a b c d e Adam M. Yates: The species taxonomy of the sauropodomorph dinosaurs from the Löwenstein Formation (Norian, Late Triassic) of Germany. In: Palaeontology. Vol. 46, No. 2, 2003, ISSN  0031-0239 , pp. 317-337, doi : 10.1111 / j.0031-0239.2003.00301.x .
  19. ↑ a b c d e f David B. Weishampel : Trossingen: E. Fraas, F. von Huene, R. Seemann, and the "Swabian Lindwurm" Plateosaurus. In: Wolf-Ernst Reif , Frank Westphal (eds.): Third symposium on Mesozoic Terrestrial Ecosystems, Tübingen 1984. Short papers. Attempto, Tübingen 1984, ISBN 3-921552-50-8 , pp. 249-253.
  20. ↑ a b c d e Otto Jaekel: About the vertebrate finds in the upper Triassic of Halberstadt. In: Palaeontological Journal. Vol. 1, No. 1, 1914, pp. 155-215, doi : 10.1007 / BF03160336 .
  21. ↑ a b Markus Schmitz / mas: Saurians in Trossingen. In: Südkurier , October 7, 2010.
  22. ^ A b c Friedrich von Huene: Life picture of the Saurischier occurrence in the uppermost Keuper of Trossingen in Württemberg. In: Palaeobiologica. Vol. 1, 1928, ZDB -ID 533418-4 , pp. 103-116.
  23. ^ Largest dinosaur skeleton in Switzerland found in Frick. Swiss radio and television , July 1, 2015, accessed on July 1, 2015 .
  24. ↑ a b Jørn Harald Hurum, Morten Bergan, Reidar Müller, Johan Petter Nystuen, Nicole Klein: A Late Triassic dinosaur bone, offshore Norway. In: Norwegian Journal of Geology. Vol. 86, No. 2, 2006, ISSN  0029-196X , pp. 117–123, digitized version (PDF; 305.25) ( Memento of the original from September 24, 2015 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. . @1@ 2Template: Webachiv / IABot / www.geologi.no
  25. ↑ Farish A. Jenkins , Neil H. Shubin , William W. Amaral, Steven M. Gatesy, Charles R. Schaff, Lars B. Clemmensen, William R. Downs, Army R. Davidson, Niels Bonde, Frank Osbaeck: Late triassic continental vertebrates and depositional environments of the Fleming Fjord Formation, Jameson Land, East Greenland (= Meddelelser om Grønland. Geoscience. Vol. 32). Commissions for videnskabelige Undersøgelser i Grønland, Copenhagen 1994, ISBN 87-601-4573-0 .
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  29. ↑ Chung-chien Yang: A complete osteology of Lufengosaurus huenei Young (gen. Et sp. Nov.) From Lufeng, Yunnan, China (= Palæontologia sinica. Series C: Fossil vertebrates of China. No. 121 = NS No. 7, ZDB ID 1168040-4 ). Geological Survey of China, Pehpei et al. 1941.
  30. ↑ José F. Bonaparte : Los tetrápodos del sector superior de la formación Los Colorados, La Rioja, Argentina (triásico superior) (= Opera Lilloana. Vol. 22, ISSN  0078-5245 ). Volume 1. Universidad Nacional de Tucumán - Fundación y Instituto Miguel Lillo, Tucumán 1971.
  31. ^ Friedrich von Huene: About the Triassic Dinosaurs of Europe. In: Journal of the German Geological Society. Vol. 57, 1905, ISSN  0012-0189 , pp. 345-349.
  32. ↑ Luciano A. Leal, Sergio AK Azevedo, Alexander WA Kellner, Átila AS Da Rosa: A new early dinosaur (Sauropodomorpha) from the Caturrita Formation (Late Triassic), Paraná Basin, Brazil (= Zootaxa . 690). Magnolia Press, Auckland 2004.
  33. ^ Adam M. Yates: A revision of the problematic sauropodomorph dinosaurs from Manchester, Connecticut and the status of Anchisaurus Marsh. In: Palaeontology. Vol. 53, No. 4, 2010, pp. 739-752, doi : 10.1111 / j.1475-4983.2010.00952.x .
  34. ↑ Max Blankenhorn: Dinosaur finds in the Franconian Keuper. In: Meeting reports of the Physikalisch-Medicinischen Societät in Erlangen. Issue 29, 1897, ISSN  0371-2117 , pp. 67-91, digitized .
  35. ↑ Louis Agassiz : Nomenclator Zoologicus, continens nomina systernatica generum animalium tam viventium quam fossilium, secundum ordinem alphabeticum disposita, adjectis auctoribus, libris in quibus reperiuntur, anno editionis, etymologia et familiis, ad quas pertinent, in sirigulis class. Fasciculus 6: Reptilia. Jent & Gassmann, Soloduri 1844.
  36. ↑ Louis Agassiz: Nomenclatoris zoologici index universalis, continens nomina systernatica classium, ordinum, familiarurn et generum animalium omnium, tam viventium quam fossilium, secundum ordinem alphabeticum unicum disposita, adjectis homonymiis, plantarum, necibus non variis et emendation. Jent & Gassmann, Soloduri 1846.
  37. ^ Alfred Vollrath: sequence of layers (stratigraphy). In: Geological State Office in Baden-Württemberg (Hrsg.): Explanations on the geological map of Stuttgart and the surrounding area. 1: 50,000. Baden-Württemberg State Surveying Office, Stuttgart 1959, pp. 27-89.
  38. ↑ Peter M. Galton: Cranial anatomy of the prosauropod dinosaur Plateosaurus from the Knollenmergel (Middle Keuper, Upper Triassic) of Germany. II. All the cranial material and details of soft-part anatomy. In: Geologica et Palaeontologica. Vol. 19, 1985, pp. 119-159.
  39. ^ Peter M. Galton: Prosauropod dinosaur Plateosaurus (= Gresslyosaurus) (Saurischia: Sauropodomorpha) from the Upper Triassic of Switzerland. In: Geologica et Paleontologica. Vol. 20, 1986, pp. 167-183.
  40. ^ Peter M. Galton: The prosauropod dinosaur Plateosaurus Meyer, 1837 (Saurischia, Sauropodomorpha). I: The syntypes of P. engelhardti Meyer, 1837 (Upper Triassic, Germany), with notes on other European prosauropods with “distally straight” femora. In: New Yearbook for Geology and Paleontology. Treatises. Vol. 216, No. 2, 2000, ISSN  0077-7749 , pp. 233-275.
  41. ^ Peter M. Galton: The prosauropod dinosaur Plateosaurus Meyer, 1837 (Saurischia: Sauropodomorpha; Upper Triassic). II. Notes on the referred species. In: Revue Paléobiologie. Vol. 20, No. 2, 2001, ISSN  0253-6730 , pp. 435-502.
  42. ↑ David B. Weishampel, Paul M. Barrett, Rodolfo A. Coria , Jean Le Loeuff, Xing Xu , Xijin Zhao , Ashok Sahni, Elizabeth Gomani, Christopher R. Noto: Dinosaur distribution. In: David B. Weishampel, Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , pp. 517-683, here p. 524.
  43. ↑ a b c Eberhard Fraas : The latest dinosaur finds in the Swabian Triassic. In: The natural sciences . Vol. 1, No. 45, 1913, pp. 1097-1100, doi : 10.1007 / BF01493265 , digitized .
  44. ↑ Reinhold Seemann : The dinosaur camp in the Keuper marl near Trossingen. In: Annual books of the Association for Patriotic Natural History in Württemberg. Vol. 89, 1933, ISSN  0368-4717 , pp. 129-160.
  45. ↑ a b David B. Weishampel, Frank Westphal: The plateosaurs of Trossingen in the geological institute of the Eberhard-Karls-Universität Tübingen (= exhibition catalogs of the University of Tübingen. Vol. 19). Attempto, Tübingen 1986, ISBN 3-921552-76-1 .
  46. ↑ Hans Rieber: The plateosaur from Frick. In: University of Zurich. No. 6, 1985, pp. 3-4.
  47. ↑ Friedrich von Huene: The dinosaurs of the European Triassic formation with consideration of the non-European occurrences (= geological and palaeontological treatises. Supplement volume 1, ZDB -ID 510890-1 ). 2 parts (text parts, table parts). Fischer, Jena 1907–1908.
  48. ↑ Otto Jaekel: The foot position and way of life of the great dinosaurs. In: Monthly reports of the German Geological Society. No. 1, 1910, ZDB -ID 564381-8 , pp. 270-277, digitized .
  49. ↑ Gustav Tornier : Comments on the statements of Mr. Jäkel. In: Journal of the German Geological Society. Vol. 64, B: Monthly Reports. No. 1, 1912, ZDB -ID 511192-4 , pp. 2-24, digitized .
  50. ↑ Eberhard Fraas: The Swabian dinosaurs. In: Annual books of the Association for Patriotic Natural History in Württemberg. Vol. 68, 1912, pp. LXVI-LXVII, digitized .
  51. ↑ Hanns Müller-Stoll: Study of the biological anatomy of the genus Plateosaurus. In: Negotiations of the Natural History Medical Association in Heidelberg. Vol. 18, No. 1, 1935, ZDB -ID 201638-2 , pp. 16-30.
  52. ↑ a b Andreas Christian, Holger Preuschoft: Deducing the body posture of extinct large vertebrates from the shape of the vertebral column. In: Palaeontology. Vol. 39, No. 4, 1996, pp. 801-812, digitized version (PDF; 768.69 kB) .
  53. ^ A b Peter M. Galton: Basal Sauropodomorpha-Prosauropoda. In: David B. Weishampel, Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . University of California Press, Berkeley CA et al. 1990, ISBN 0-520-06726-6 , pp. 320-344.
  54. ^ A b Peter M. Galton, Paul Upchurch : Prosauropoda. In: David B. Weishampel, Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , pp. 232-258.
  55. ↑ a b Gregory S. Paul: Dinosaur models: the good, the bad, and using them to estimate the mass of dinosaurs. In: Donald L. Wolberg, Edmund Stump, Gary Rosenberg (Eds.): Dinofest International. Proceedings of a Symposium held at Arizona State University. Academy of Natural Sciences, Philadelphia PA 1997, ISBN 0-935868-94-1 , pp. 129-154, digitized version (PDF; 13.26 MB) .
  56. ^ A b Peter Wellnhofer : Prosauropod dinosaurs from the Feuerletten (Middle Norian) of Ellingen near Weissenburg in Bavaria. In: Revue de Paléobiologie. Volume special. 7, 1993, ISSN  0253-6730 , pp. 263-271.
  57. ↑ Matthew F. Bonnan, Phil Senter: Were the basal dinosaurs sauropodomorpha Plateosaurus and Massospondylus habitual quadrupeds? In: Paul M. Barrett, David J. Batten (eds.): Evolution and palaeobiology of early sauropodomorph dinosaurs (= Special Papers in Palaeontology. Vol. 77). The Palaeontological Association, London 2007, ISBN 978-1-4051-6933-2 , pp. 139-155.
  58. ^ Heinrich Mallison: Plateosaurus in 3D: How CAD Models and Kinetic-Dynamic Help Bringing an Extinct Animal to life. In: Nicole Klein, Kristian Remes, Carole T. Gee, P. Martin Sander (Eds.): Biology of the Sauropod Dinosaurs. Understanding the Life of Giants. Indiana University Press, Bloomington IN et al. 2011, ISBN 978-0-253-35508-9 , pp. 216-236.
  59. ↑ Stephen M. Gatesy: Caudofemoral musculature and the evolution of theropod locomotion. In: Paleobiology. Vol. 16, No. 2, 1990, ISSN  0094-8373 , pp. 170-186.
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  61. ↑ Oliver Wings: A review of gastrolith function with implications for fossil vertebrates and a revised classification. In: Acta Palaeontologica Polonica. Vol. 52, No. 1, 2007, pp. 1-16, online .
  62. ↑ a b Oliver Wings, P. Martin Sander: No gastric mill in sauropod dinosaurs: new evidence from analysis of gastrolith mass and function in ostriches. In: Proceedings of the Royal Society. Series B: Biological Sciences. Vol. 274, No. 1610, 2007, ISSN  0080-4649 , pp. 635-640, doi : 10.1098 / rspb . 2006.3763 .
  63. ^ P. Martin Sander: Life history of Tendaguru sauropods as inferred from long-bone histology. In: Messages from the Museum of Natural History in Berlin. Earth science series. Vol. 2, No. 1, 1999, ISSN  1435-1943 , pp. 103-112, doi : 10.1002 / mmng.1999.4860020107 .
  64. ^ A b Nicole Klein, P. Martin Sander: Bone histology and growth of the prosauropod dinosaur Plateosaurus engelhardti von Meyer, 1837 from the norian bonebeds of Trossingen (Germany) and Frick (Switzerland). In: Paul M. Barrett, David J. Batten (eds.): Evolution and palaeobiology of early sauropodomorph dinosaurs (= Special Papers in Palaeontology. Vol. 77). The Palaeontological Association, London 2007, ISBN 978-1-4051-6933-2 , pp. 169-206.
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