Dorygnathus ("spear jaw") was a genus of pterosaur that lived in Europe during the Early Jurassic period, 180 million years ago when shallow seas flooded much of the continent. It had a short 1.5 meters (4.9 feet) wingspan, and a relatively small triangular sternum, which is where its flight muscles attached. Its skull was long and its eye sockets were the largest opening therein. Large curved fangs that "intermeshed" when the jaws closed featured prominently at the front of the snout while smaller, straighter teeth lined the back. Having variable teeth, a condition called heterodonty, is rare in modern reptiles but more common in primitive pterosaurs. The heterodont dentition in Dorygnathus is consistent with a piscivorous (fish-eating) diet. The fifth digit on the hindlimbs of Dorygnathus was unusually long and oriented to the side. Its function is not certain, but the toe may have supported a membrane like those supported by its wing-fingers and pteroids. Dorygnathus was according to David Unwin related to the Late Jurassic pterosaur, Rhamphorhynchus and was a contemporary of Campylognathoides in Holzmaden and Ohmden.
|A cast of UUPM R 156 in Göteborgs Naturhistoriska Museum, a specimen sold by Bernhard Hauff to the University of Uppsala in 1925|
Dorygnathus in general has the build of a basal, i.e. non-pterodactyloid pterosaur: a short neck, a long tail and short metacarpals — although for a basal pterosaur the neck and metacarpals of Dorygnathus are again relatively long. The skull is elongated and pointed. The largest known cranium, that of specimen MBR 1920.16 prepared by Bernard Hauff in 1915 and eventually acquired by the Natural History Museum of Berlin, has a length of sixteen centimetres. In the skull the eye socket forms the largest opening, larger than the fenestra antorbitalis that is clearly separated from the slit-like bony naris. No bony crest is visible on the rather straight top of the skull or snout. The lower jaws are thin at the back but deeper toward the front where they fuse into the symphysis ending in a toothless point after which the genus has been named. In MBR 1920.16, the mandibula as a whole has a length of 147 millimetres.
In the lower jaws the first three pairs of teeth are very long, sharp and pointing outwards and forwards. They contrast with a row of eight or more upright-standing much smaller teeth that gradually diminish in size towards the back of the lower jaw. No such extreme contrast exists in the upper jaws, but the four teeth in the premaxilla are longer than the seven in the maxilla that again become smaller posteriorly. The total number of teeth is thus at least 44. The long upper and lower front teeth interlaced when the beak was closed; due to their extreme length they then projected considerably beyond the upper and lower margins of the head.
According to Padian, eight cervical, fourteen dorsal, three or four sacral and twenty-seven or twenty-eight caudal vertebrae are present. The exceptional fourth sacral is the first of the normal caudal series. The number of caudals is not certain because their limits are obscured by long thread-like extensions, stiffening the tail. The cervical vertebrae are rather long and strongly built, their upper surface having a roughly square cross-section. They carry double-headed thin cervical ribs. The dorsal vertebrae are more rounded with flat spines; the first three or four carry ribs that contact the sternal ribs; the more posterior ribs contact the gastralia. The first five or six, rather short, caudal vertebrae form a flexible tail base. To the back the caudals grow longer and are immobilised by their intertwining extensions with a length of up to five vertebrae which together surround the caudals with a bony network, allowing the tail to function as a rudder.
The breastbone is triangular and relatively small; Padian has suggested it may have been extended at its back with a cartilaginous tissue. It is connected to the coracoid which in older individuals is fused to the longer scapula forming a saddle-shaped shoulder joint. The humerus has a triangular deltopectoral crest and is pneumatised. The lower arm is 60% longer than the upper arm. From the five carpal bones in the wrist a short but robust pteroid points towards the neck, in the living animal a support for a flight membrane, the propatagium. The first three metacarpals are connected to three small fingers, equipped with short but strongly curved claws; the fourth to the wing finger, in which the second or third phalanx is the longest; the first or fourth the shortest. The wing finger supports the main flight membrane.
In the pelvis, the ilium, ischium and pubis are fused. The ilium is elongated with a length of six vertebrae. The lower leg, in which the lower two thirds of the tibia and fibula of adult specimens are fused, is a third shorter than the thighbone, the head of which makes an angle of 45° with its shaft. The proximal tarsals are never fused in a separate astragalocalcaneum; a tibiotarsus is formed. The third metatarsal is the longest; the fifth is connected to a toe of which the second phalanx shows a 45° bend and has a blunt and broad end; it perhaps supported a membrane between the legs, a cruropatagium.
In some specimens, soft parts have been preserved but these are rare and limited, providing little information. It is unknown whether the tail featured a vane on its end, as with Rhamphorhynchus. However, Ferdinand Broili reported the presence of hairs in specimen BSP 1938 I 49, an indication that Dorygnathus also had fur and an elevated metabolism, as is presently assumed for all pterosaurs.
The first remains of Dorygnathus, isolated bones and jaw fragments from the Schwarzjura, the Posidonia Shale dating from the Toarcian, were discovered near Banz, Bavaria and in 1830 described by Carl Theodori as Ornithocephalus banthensis, the specific name referring to Banz. The holotype, a lower jaw, is PSB 757. The fossils were studied by Christian Erich Hermann von Meyer in 1831 and again by Theodori in 1852 when he referred them to the genus Rhamphorhynchus. In this period a close affinity was assumed with a pterosaur known from Britain, later named Dimorphodon. Some fossils were sent to a professor of paleontology in Munich named Johann Andreas Wagner. It was he who, having studied new finds by Albert Oppel in 1856 and 1858, after Richard Owen had named Dimorphodon concluded that the German type was clearly different and that therefore a new genus of pterosaur should be erected, which he formally named Dorygnathus in 1860, from Greek dory, "spear" and gnathos, "jaw". Much more complete remains have been found since in other German locales and especially in Württemberg, including Holzmaden, Ohmden, and Zell. One specimen, SMNS 81840, has in 1978 been dug up in Nancy, France. Dorygnathus fossils were often found in the spoil heaps where unusable rock was dumped from slate quarries worked by local farmers. Most fossils were found in two major waves, one during the twenties, the other during the eighties of the twentieth century. Since then the rate of discovery has slowed considerably because the demand for slate has strongly diminished and many small quarries have closed. At present over fifty specimens have been collected, many of them are preserved in the collection of the State Museum of Natural History Stuttgart, as by law paleontological finds in Baden-Württemberg are property of this Bundesland. Due to the excellent preserval of the later found fossils, Dorygnathus has generated much interest by pterosaur researchers, important studies having been dedicated to the species by Felix Plieninger, Gustav von Arthaber, and more recently Kevin Padian.
In 1971 Rupert Wild described and named a second species: Dorygnathus mistelgauensis, based on a specimen collected in a brick pit near the railway station of Mistelgau, to which the specific name refers, by teacher H. Herppich, who donated it to the private collection of Günther Eicken, a local amateur paleontologist at Bayreuth, where it still resides. As a result the exemplar has no official inventory number. The fossil comprises a shoulder-blade with wing, a partial leg, a rib and a caudal vertebra. Wild justified the creation of a new species name by referring to the great size, with an about 50% larger wingspan than with a typical specimen; the short lower leg and the long wing.
Padian in 2008 pointed out that D. banthensis specimen MBR 1977.21, the largest then known, has with a wingspan of 169 centimetres an even larger size; that wing and lower leg proportions are rather variable in D. banthensis and that the geological age is comparable. He concluded that D. mistelgauensis is a subjective junior synonym of D. banthensis.
The affinity between Dorygnathus and Dimorphodon, assumed by early researchers, was largely based on a superficial resemblance in tooth form. Baron Franz Nopcsa in 1928 assigned the species to the Rhamphorhynchinae, which was confirmed by Peter Wellnhofer in 1978. Modern exact cladistic analyses of the relationships of Dorygnathus have not resulted in a consensus. David Unwin in 2003 found that it belonged to the clade Rhamphorhynchinae, but analyses by Alexander Kellner resulted in a much more basal position, below Dimorphodon or Peteinosaurus. Padian, using a comparative method, in 2008 concluded that Dorygnathus was close to Scaphognathus and Rhamphorhynchus in the phylogenetic tree but also that these species were forming a series of successive off-shoots, meaning that they would not be united in a separate clade. This was again contradicted by the results of a cladistic study by Brian Andres in 2010 showing that Dorygnathus was part of a monophyletic Rhamphorhynchinae. The following cladogram shows the position of Dorygnathus according to Andres:
Dorygnathus is commonly thought to have had a piscivorous way of living, catching fish or other slippery sea-creatures with its long teeth. This is confirmed by the fact that the fossils have been found in marine sediments, deposited in the seas of the European Archipelago. In these it is present together with the pterosaur Campylognathoides that however is much more rare. Very young juveniles of Dorygnathus are unknown, the smallest discovered specimen having a wingspan of sixty centimetres; perhaps they were unable to venture far over open sea. Padian concluded that Dorygnathus after a relatively fast growth in its early years, faster than any modern reptile of the same size, kept slowly growing after having reached sexual maturity, which would have resulted in exceptionally large individuals with a 1.7 metres (5.6 feet) wingspan.
On land, Dorygnathus was probably not a good climber; its claws show no special adaptations for this type of locomotion. According to Padian, Dorygnathus, as a small pterosaur with a long tail, was well capable of bipedal movement, though its long metacarpals would make him better suited for a quadrupedal walk than most basal pterosaurs. Most researchers however, today assume quadrupedality for all pterosaurs.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1860.Allkaruen
Allkaruen (meaning "ancient brain") is a genus of rhamphorhynchoid pterosaur from the Early-to-Middle Jurassic Cañadon Asfalto Formation in Argentina. It contains a single species, A. koi.Anchisauria
The Anchisauria were a clade of sauropodomorph dinosaurs that lived during the Late Triassic and Early Jurassic. The name Anchisauria was first used by Galton and Upchurch in the second edition of The Dinosauria. Galton and Upchurch assigned two families of dinosaurs to the Anchisauria: the Anchisauridae and the Melanorosauridae. The more common prosauropods Plateosaurus and Massospondylus were placed in the sister clade Plateosauria.
However, recent research indicates that Anchisaurus is closer to sauropods than traditional prosauropods; thus, Anchisauria would also include Sauropoda.The following cladogram simplified after an analysis presented by Blair McPhee and colleagues in 2014.Angustinaripterus
Angustinaripterus was a basal pterosaur, belonging to the Breviquartossa, and discovered at Dashanpu near Zigong in the Szechuan province of China.
Angustinaripterus was named in 1983 by He Xinlu.
The type species is Angustinaripterus longicephalus. The genus name is derived from Latin angustus, "narrow" and naris, "nostril", combined with Latinized Greek pteron, "wing". The specific name is derived from Latin longus, "long", and Greek kephale, "head".
The holotype, ZDM T8001, is a single skull with lower jaws, found in 1981 by researchers from the Zigong Historical Museum of the Salt Industry, in the Xiashaximiao Formation (Bathonian).
The skull, of which the left side is severely damaged, is very elongated and flat. The back part is missing; in its preserved state it has a length of 192 millimetres; the total length in a complete state was estimated at 201 millimetres. On its top is a low crest, two to three millimetres high. The nares are long, slit-like and positioned above and in front of the large skull openings, the fenestrae antorbitales, with which they are not confluent. Of the jaws, which are very straight, the front part is lacking. There are six pairs of teeth in the maxillae and three pairs in the praemaxillae. In the mandible there are at least ten pairs of teeth, perhaps twelve. The back teeth are small, the front teeth are very long, robust and curved, pointing moderately forwards. At the front they form a large, intermeshing "prey grab", that may have been used to snatch fish from the water surface. The teeth of Angustinaripterus resemble those of Dorygnathus.
He placed Angustinaripterus into the Rhamphorhynchidae. Because of the derived morphology and the large geographical distance with comparable European forms He also created a special subfamily Angustinaripterinae, of which Angustinaripterus itself is the only known member; because of this redundancy the concept is rarely used. He concluded that Angustinaripterus was directly related to the Scaphognathinae. David Unwin however, considers it a member of the other rhamphorhynchid subgroup: the Rhamphorhynchinae.
Peter Wellnhofer in 1991, assuming the skull length was 16.5 centimetres (6.5 inches), estimated the wingspan at 1.6 metres (5.25 ft).Averostra
Averostra, or "bird snouts", is a clade that includes most theropod dinosaurs that have a promaxillary fenestra (fenestra promaxillaris), an extra opening in the front outer side of the maxilla, the bone that makes up the upper jaw. Two groups of averostrans, the Ceratosauria and the Orionides, survived into the Cretaceous period. When the Cretaceous–Paleogene extinction event occurred, ceratosaurians and two groups of orionideans within the clade Coelurosauria, the Tyrannosauroidea and Maniraptoriformes, were still extant. Only one subgroup of maniraptoriformes, Aves, survived the extinction event and persisted to the present day.Avetheropoda
Avetheropoda, or "bird theropods", is a clade that includes carnosaurians and coelurosaurs to the exclusion of other dinosaurs.Caelestiventus
Caelestiventus ( sə-LES-tih-VEN-təs, meaning "heavenly wind") is a pterosaur genus from the Late Triassic (Norian or Rhaetian) found in western North America. The type species, Caelestiventus hanseni, honors Robin Hansen, the Bureau of Land Management geologist (BLM), who facilitated access to the excavation site.
Caelestiventus is important because it is the sole example of a desert-dwelling non-pterodactyloid pterosaur and is 65 million years older than other known desert-dwelling pterosaurs. Additionally, it shows that even the earliest pterosaurs were morphologically and ecologically diverse and that the Dimorphodontidae originated in the Triassic Period.Campylognathoides
Campylognathoides ("curved jaw", Strand 1928) is a genus of pterosaur, discovered in the Württemberg Lias deposits (dated to the early Toarcian age) of Germany; this first specimen consisted however only of wing fragments. Further better preserved specimens were found in the Holzmaden shale: basing on these specimens Felix Plieninger erected a new genus.Cerapoda
Cerapoda ("ceratopsians and ornithopods") is a clade of the dinosaur order Ornithischia.Changchengopterus
Changchengopterus is a genus of non-pterodactyloid pterosaur from China, Qinglong County, Hebei Province.
The fossil specimen, holotype CYGB-0036, of the type and only species, Changchengopterus pani, was found in the Tiaojishan Formation dating from the Callovian and named and described by Lü Junchang in 2009. The generic name combines the Changcheng, the Great Wall of China, with a Latinised Greek pteron, "wing". The specific name honours Pan Lijun, who collected the fossil and donated it to science. The holotype, a skeleton lacking the skull, represents a young juvenile, of which the combined paired wing elements measure just seventeen centimetres. In 2011, a second specimen was described, PMOL-AP00010, acquired in 2008 by the Paleontological Museum of Liaoning. It consists of a skeleton with lower jaws, of an adult individual.The wingspan of the referred specimen was in 2011 estimated at seventy centimetres. Already in 2010, some estimates for the genus had risen to 475 millimetres (18.7 in).In his original description, Lü's phylogenetic analysis concluded that Changchengopterus was a primitive pterosaur closely related to the earlier European pterosaur Dorygnathus, and he placed it in Rhamphorhynchidae. However, a subsequent study by Wang and colleagues (2010) noted some similarities with the wukongopterids, and they tentatively placed it in that family. Andres & Myers (2013) found it to be outside Wukongopteridae and slightly more closely related to the pterodactyloids within the larger group Monofenestrata.Dinosauriformes
Dinosauriformes is a clade of archosaurian reptiles that include the dinosaurs and their most immediate relatives. All dinosauriformes are distinguished by several features, such as shortened forelimbs and a partially to fully perforated acetabulum, the hole in the hip socket traditionally used to define dinosaurs. The oldest known member is Asilisaurus, dating to about 245 million years ago in the Anisian age of the middle Triassic period.Jingshanosaurus
Jingshanosaurus (meaning "Jingshan lizard") is a genus of sauropodomorph dinosaurs from the early Jurassic period.Neotheropoda
Neotheropoda (meaning "new theropods") is a clade that includes coelophysoids and more advanced theropod dinosaurs, and the only group of theropods who survived the Triassic–Jurassic extinction event. Yet all of the neotheropods became extinct during the early Jurassic period except for Averostra.Orionides
Orionides is a clade of tetanuran theropod dinosaurs from the Middle Jurassic to the Present. The clade includes most theropod dinosaurs, including birds.Orodrominae
Orodrominae is a subfamily of parksosaurid dinosaurs from the Cretaceous of North America and Asia.Parapsicephalus
Parapsicephalus (meaning "beside arch head") is a genus of long-tailed rhamphorhynchid pterosaurs from the Lower Jurassic Whitby, Yorkshire, England. It contains a single species, P. purdoni, named initially as a species of the related rhamphorhynchid Scaphognathus in 1888 but moved to its own genus in 1919 on account of a unique combination of characteristics. In particular, the top surface of the skull of Parapsicephalus is convex, which is otherwise only seen in dimorphodontians. This has been the basis of its referral to the Dimorphodontia by some researchers, but it is generally agreed upon that Parapsicephalus probably represents a rhamphorhynchid. Within the Rhamphorhynchidae, Parapsicephalus has been synonymized with the roughly contemporary Dorygnathus; this, however, is not likely given a large number of differences between the two taxa, including the aforementioned convex top surface of the skull. Parapsicephalus has been tentatively referred to the Rhamphorhynchinae subgrouping of rhamphorhynchids, but it may represent a basal member of the group instead.Preondactylus
Preondactylus is a genus of long-tailed pterosaurs from the Late Triassic (late Carnian or early Norian age, about 228 million years ago) that inhabited what is now Italy. It contains a single known species, Preondactylus buffarinii, which was discovered by Nando Buffarini in 1982 at the Forni Dolostone near Udine in the Preone valley of the Italian Alps.Rhamphorhynchidae
Rhamphorhynchidae is a group of early "rhamphorhynchoid" pterosaurs named after Rhamphorhynchus, that lived in the Late Jurassic. The family Rhamphorhynchidae was named in 1870 by Harry Govier Seeley.Xixiposaurus
Xixiposaurus is a genus of prosauropod dinosaur which existed in what is now Lower Lufeng Formation, China during the lower Jurassic period. It was first named by Sekiya Toru in 2010 and the type species is Xixiposaurus suni.