Pterodactylus (from ) is a genus of extinct pterosaurs. It is thought to contain only a single species, Pterodactylus antiquus, which was the first pterosaur to be named and identified as a flying reptile and one of the first prehistoric reptiles ever to be discovered.
Fossil remains of Pterodactylus have primarily been found in the Solnhofen limestone of Bavaria, Germany, which dates from the Late Jurassic period (Tithonian stage), about 150.8 to 148.5 million years ago. More fragmentary remains of Pterodactylus have tentatively been identified from elsewhere in Europe and in Africa.
Pterodactylus was a generalist carnivore that probably fed on a variety of invertebrates and vertebrates. Like all pterosaurs, Pterodactylus had wings formed by a skin and muscle membrane stretching from its elongated fourth finger to its hind limbs. It was supported internally by collagen fibres and externally by keratinous ridges. Pterodactylus was a small pterosaur compared to other famous genera such as Pteranodon and Quetzalcoatlus, and it also lived earlier, during the Late Jurassic period, while both Pteranodon and Quetzalcoatlus lived during the Late Cretaceous. Pterodactylus lived alongside other small pterosaurs such as the well-known Rhamphorhynchus, as well as other genera such as Scaphognathus, Anurognathus and Ctenochasma. Pterodactylus is classified as an early-branching member of the ctenochasmatid lineage, within the pterosaur clade Pterodactyloidea. The specimen had been given to the collection by Count around 1780, having been recovered from a lithographic limestone quarry in . The actual date of the specimen's discovery and entry into the collection is unknown however, and it was not mentioned in a catalogue of the collection taken in 1767, so it must have been acquired at some point between that date and its 1784 description by Collini. This makes it potentially the earliest documented pterosaur find; the "Pester Exemplar" of the genus Aurorazhdarcho was described in 1779 and possibly discovered earlier than the Mannheim specimen, but it was at first considered to be a fossilized crustacean, and it was not until 1856 that this species was properly described as a pterosaur by German paleontologist .
thumb|left|Wagler's 1830 restoration of an aquatic Pterodactylus
In his first description of the Mannheim specimen, Collini did not conclude that it was a flying animal. In fact, Collini could not fathom what kind of animal it might have been, rejecting affinities with the birds or the bats. He speculated that it may have been a sea creature, not for any anatomical reason, but because he thought the ocean depths were more likely to have housed unknown types of animals. The idea that pterosaurs were aquatic animals persisted among a minority of scientists as late as 1830, when the German zoologist Johann Georg Wagler published a text on "amphibians" which included an illustration of Pterodactylus using its wings as flippers. Wagler went so far as to classify Pterodactylus, along with other aquatic vertebrates (namely plesiosaurs, ichthyosaurs, and monotremes), in the class Gryphi, between birds and mammals.
thumb|Hermann's original life restoration, the first of any pterosaur, 1800
The German/French scientist Johann Hermann was the one who first stated that Pterodactylus used its long fourth finger to support a wing membrane. Back in March 1800, Hermann alerted the prominent French scientist Georges Cuvier to the existence of Collini's fossil, believing that it had been captured by the invading forces of the French Consulate and sent to collections in Paris (and perhaps to Cuvier himself) as war booty; at the time special French political commissars systematically seized art treasures and objects of scientific interest. Hermann sent Cuvier a letter containing his own interpretation of the specimen (though he had not examined it personally), which he believed to be a mammal, including the first known life restoration of a pterosaur. Hermann restored the animal with wing membranes extending from the long fourth finger to the ankle and a covering of fur (neither wing membranes nor fur had been preserved in the specimen). Hermann also added a membrane between the neck and wrist, as is the condition in bats. Cuvier agreed with this interpretation, and at Hermann's suggestion, Cuvier became the first to publish these ideas in December 1800 in a very short description. The specimen had not in fact been seized by the French. Rather, in 1802, following the death of Charles Theodore, it was brought to Munich, where Baron Johann Paul Carl von Moll had obtained a general exemption of confiscation for the Bavarian collections. this was a typographical error however, and was later corrected by him to Ptéro-Dactyle.
thumb|Von Sömmerring's incorrect 1817 restoration of the species [[Pterodactylus brevirostris]]
Contrary to von Moll's report, the fossil was not missing; it was being studied by Samuel Thomas von Sömmerring, who gave a public lecture about it on December 27, 1810. In January 1811, von Sömmerring wrote a letter to Cuvier deploring the fact that he had only recently been informed of Cuvier's request for information. His lecture was published in 1812, and in it von Sömmerring named the species Ornithocephalus antiquus. The animal was described as being both a bat, and a form in between mammals and birds, i.e. not intermediate in descent but in "affinity" or archetype. Cuvier disagreed, and the same year in his Ossemens fossiles provided a lengthy description in which he restated that the animal was a reptile. It was not until 1817 that a second specimen of Pterodactylus came to light, again from Solnhofen. This tiny specimen was that year described by von Sömmerring as Ornithocephalus brevirostris, named for its short snout, now understood to be a juvenile character. Sömmerring did not change his opinion that these forms were bats and this "bat model" for interpreting pterosaurs would remain influential long after a consensus had been reached around 1860 that they were reptiles. The standard assumptions were that pterosaurs were quadrupedal, clumsy on the ground, furred, warmblooded and had a wing membrane reaching the ankle. Some of these elements have been confirmed, some refuted by modern research, while others remain disputed.
In 1815, the generic name Ptéro-Dactyle was latinized to Pterodactylus by Constantine Samuel Rafinesque. Unaware of Rafinesque's publication however, Cuvier himself in 1819 latinized the name Ptéro-Dactyle again to Pterodactylus, but the specific name he then gave, longirostris, has to give precedence to von Sömmerring's antiquus. Pterodactylus antiquus was a relatively small pterosaur, with an estimated adult wingspan of about , based on the only known adult specimen, which is represented by an isolated skull. However, these smaller specimens have been shown to represent juveniles of Pterodactylus, as well as its contemporary relatives including Ctenochasma, Germanodactylus, Aurorazhdarcho, Gnathosaurus, and hypothetically Aerodactylus if this genus is truly valid.
The skulls of adult Pterodactylus were long and thin, with about 90 narrow and conical teeth. The teeth extended back from the tips of both jaws, and became smaller farther away from the jaw tips. This was unlike the ones seen in most relatives, where teeth were absent in the upper jaw tip and were relatively uniform in size. The teeth of Pterodactylus also extended farther back into the jaw compared to close relatives, and some were present below the front of the nasoantorbital fenestra, which is the largest opening in the skull. In 2013, pterosaur researcher S. Christopher Bennett noted that other authors claimed that the soft tissue crest of Pterodactylus extended backward behind the skull; Bennett himself, however, didn't find any evidence for the crest extending past the back of the skull. The second year class represents individuals one to two years old, and the rare third year class is composed of specimens over two years old. This growth pattern is similar to modern crocodilians, rather than the rapid growth of modern birds.
Diet
Based on the shape, size, and arrangement of its teeth, Pterodactylus has long been recognized as a carnivore specializing in small animals. A 2020 study of pterosaur tooth wear supported the hypothesis that Pterodactylus preyed mainly on invertebrates and had a generalist feeding strategy, indicated by a relatively high bite force.
Paleoecology
thumb|left|Hypothetical restoration of Pterodactylus in its environment
Specimens of Pterodactylus have been found mainly in the Solnhofen limestone (geologically known as the Altmühltal Formation) of Bavaria, Germany. The main composition of this formation is fine-grained limestone that originated mainly from the nearby towns Solnhofen and Eichstätt, which is formed by mud silt deposits. several gallodactylids such as Aerodactylus, and Gnathosaurus, the anurognathid Anurognathus, the germanodactylid Germanodactylus, as well as the basal euctenochasmatian Diopecephalus. Various lizard remains were also found alongside those of Pterodactylus, with several specimens assigned to Ardeosaurus, Bavarisaurus and Eichstaettisaurus. Crocodylomorph specimens were widely distributed within the fossil site, most were assigned to the metriorhynchid genera Cricosaurus, Dakosaurus, Geosaurus and Rhacheosaurus. These genera are colloquially called as marine or sea crocodiles due to their similar built. The turtle genera Eurysternum and Paleomedusa were also found within the formation. Fossils of the ichthyosaur Aegirosaurus also appeared to be present in the site, as well as fish remains, with many specimens assigned to ray-finned fishes such as the halecomorphs Lepidotes, Ophiopsis and Ophiopsiella, the pachycormids Asthenocormus, Hypsocormus and Orthocormus, as well as the aspidorhynchid Aspidorhynchus, and the ichthyodectid Thrissops.
Classification
thumb|A P. antiquus specimen and counterplate (AMNH 1942) showing muscle impressions in the chest and wing membranes
Initial classifications for Pterodactylus started when paleontologist Hermann von Meyer used the name Pterodactyli to contain Pterodactylus and other pterosaurs known at the time. This was emended to the family Pterodactylidae by Prince Charles Lucien Bonaparte in 1838. However, this group has more recently been given several competing definitions.
Beginning in 2014, researchers Steven Vidovic and David Martill constructed an analysis in which several pterosaurs traditionally thought of as archaeopterodactyloids closely related to the ctenochasmatoids may have been more closely related to the more advanced dsungaripteroids, or in some cases, fall outside both groups. Their conclusion was published in 2017, in which they placed Pterodactylus as a basal member of the suborder Pterodactyloidea.
Formerly assigned species
thumb|left|Fossil specimen of the species [[Rhamphorhynchus muensteri, which was previously assigned as the species Pterodactylus münsteri]]
Numerous species have been assigned to Pterodactylus in the years since its discovery. In the first half of the 19th century any new pterosaur species would be named Pterodactylus, which thus became a "wastebasket taxon". Further fossil preparations had uncovered teeth, to which Graf zu Münster created a skull cast. He later sent the cast to Professor Georg August Goldfuss, who recognized it as a pterosaur, specifically a species of Pterodactylus. At the time however, most paleontologists incorrectly consider the genus Ornithocephalus () to be the valid name for Pterodactylus, and therefore the specimen found was named as Ornithocephalus Münsteri, which was first mentioned by Graf zu Münster himself. Another specimen was found and described by Graf zu Münster in 1839, he assigned this specimen to a new separate species called Ornithocephalus longicaudus; the specific name means 'long tail', in reference to the animal's tail size. German paleontologist Hermann von Meyer in 1845 officially emended that the genus Pterodactylus had priority over Ornithocephalus, so he reassigned the species O. münsteri and O. longicaudus into Pterodactylus münsteri and Pterodactylus longicaudus. In 1846, von Meyer created the new species Pterodactylus gemmingi based on long-tailed remains; the specific name honors the fossil collector Carl Eming von Gemming. Later, in 1847, von Meyer finally erected the generic name Rhamphorhynchus () due to the distinctively long tails seen in the specimens found, which are much longer than those seen in Pterodactylus. He assigned the species P. longicaudus as the type species of Rhamphorhynchus, which resulted in a new combination called Rhamphorhynchus longicaudus. The species R. münsteri was later changed to R. muensteri by Lydekker in 1888, due to the ICZN rule that prohibits non-standard Latin characters, such as ü, in scientific names. the specific name means 'the gigantic one' in Latin, in reference to the large size of the remains, and the second species was named in 1851 as Pterodactylus cuvieri, in honor of the French scientist Georges Cuvier. Later in 1851, Owen named and described new pterosaur specimens that have been found yet again in England. He assigned these specimens to a new species called Pterodactylus compressirostris. In 1914 however, paleontologist Reginald Hooley redescribed P. compressirostris, to which he erected the genus Lonchodectes (), and therefore made P. compressirostris the type species, and created the new combination L. compressirostris. In a 2013 review, P. giganteus and P. cuvieri were reassigned to new genera; P. giganteus was reassigned to a genus called Lonchodraco ('lance dragon'), which resulted in a new combination called L. giganteus, and P. cuvieri was reassigned to the new genus Cimoliopterus ('chalk wing'), creating C. cuvieri. Back in 1859, Owen had found remains the front part of a snout in the Cambridge Greensand, and assigned it into the species Pterodactylus segwickii; in honor of Adam Sedgwick, a British geologist. This species however, was reassigned to the genus Camposipterus in 2013, therefore creating the new combination Camposipterus segwickii. though the British paleontologist Harry Govier Seeley had created a separate generic name called Ornithocheirus, and reassigned P. simus as the type species, which created the combination Ornithocheirus simus. Between the years 1869 and 1870, Seeley had reassigned many pterosaur species into Ornithocheirus, while also creating several new species. Many of these species however, are now reclassified to other genera, or considered . this species however, was reassigned to the genus Lonchodectes in 1914 by Hooley, which resulted in an L. sagittirostris.
thumb|left|Specimen YPM1177, the first uncovered skull of [[Pteranodon, which was back then assigned as a species of Pterodactylus]]
Assigning new pterosaur species to Pterodactylus was not only common in Europe, but also in North America; paleontologists such as Othniel Charles Marsh in 1871 for example, described several toothless pterosaur specimens, which were accompanied by teeth that belonged to the fish Xiphactinus, which Marsh assumed that these teeth belonged to the pterosaur specimens he found, since all pterosaurs discovered at the time had teeth. He then assigned these specimens to a new species called "Pterodactylus oweni", but this was changed to Pterodactylus occidentalis because "P. oweni" was found to have been preoccupied by a pterosaur species described with the same name back in 1864 by Seeley. In 1872, American paleontologist Edward Drinker Cope also found various pterosaur specimens in North America, he assigned these to two new species known as Ornithochirus umbrosus and Ornithochirus harpyia, Cope attempted to assign the specimens he found to the genus Ornithocheirus, but misspelled forgetting the 'e'. In 1875 however, Cope reassigned the species O. umbrosus and O. harpyia into Pterodactylus umbrosus and Pterodactylus harpyia, though these species had been considered ever since.
Later, in the 1980s, subsequent revisions by Peter Wellnhofer had reduced the number of recognized species to about half a dozen. Many species assigned to Pterodactylus had been based on juvenile specimens, and subsequently been recognized as immature individuals of other species or genera. By the 1990s it was understood that this was even true for part of the remaining species. P. elegans, for example, was found by numerous studies to be an immature Ctenochasma. Another species of Pterodactylus originally based on small, immature specimens was P. micronyx. However, it has been difficult to determine exactly of what genus and species P. micronyx might be the juvenile form. Stéphane Jouve, Christopher Bennett and others had once suggested that it probably belonged either to Gnathosaurus subulatus or one of the species belonging to Ctenochasma. Another species with a complex history is P. longicollum, named by von Meyer in 1854, based on a large specimen with a long neck and fewer teeth. Many researchers, including David Unwin, have found P. longicollum to be distinct from P. kochi and P. antiquus. Unwin found P. longicollum to be closer to Germanodactylus and therefore requiring a new genus name. "P." longicollum was eventually made the type species of a separate genus Ardeadactylus. More recent studies of pterosaur relationships have found anurognathids and pterodactyloids to be sister groups, which would limit the more inclusive group Caelidracones to just two clades.
In 2017, Bennett challenged this hypothesis, he claimed that while Vidovic and Martill had identified real differences between these three groups of specimens, they had not provided any rationale that the differences were enough to distinguish them as species, rather than just individual variation, growth changes, or simply due to crushing and distortion during the fossilization process. Bennett pointed in particular to the data used to distinguish Aerodactylus, which was so different from the data for related species, it might be due to an unnatural assemblage of specimens. As a result, Bennett continued to consider Diopecephalus and Aerodactylus simply as year-classes of immature Pterodactylus antiquus.
List of species
During its over-200-year history, the various species of Pterodactylus have gone through a number of changes in classification and thus have acquired a large number of synonyms. Additionally, a number of species assigned to Pterodactylus are based on poor remains that have proven difficult to assign to one species or another and are therefore considered (). The following list includes names that were used to identify new pterosaur species that now have been reclassified, or until recently thought to be pertaining to Pterodactylus proper, and names based on other material that has as yet not been assigned to other genera. This list also includes species that are ('naked names'), which are species that were not published formally. Species that are ('forgotten names') are the ones that have been disused, and species that are ('rejected names') are the ones that have been rejected because a more preferable name had been accepted instead.
{| class="wikitable sortable"
|-
! Name
! Author
! Year
! Status
! class="unsortable" | Notes
|-
|Pterodactylus antiquus
|(Sömmerring)
|(1812)
|Valid
|Designated as the type species of Pterodactylus, and replacing Ornithocephalus antiquus due to being an obsolete name
|-
|Pterodactylus "suevicus"
|Oken
|1816
|Nomen nudum
|
|-
|Pterodactylus brevirostris
|(Sömmerring)
|(1817)
|Synonym of Pterodactylus antiquus
|Reclassified from Ornithocephalus brevirostris
|-
|Pterodactylus giganteus
|(Oken)
|(1819)
|Nomen dubium
|Synonym of Rhamphorhynchus muensteri; reclassified from Ornithocephalus giganteus
|-
|Pterodactylus longirostris
|Cuvier
|1819
|Synonym of Pterodactylus antiquus
|
|-
|Pterodactylus grandis
|Cuvier
|1824
|Nomen dubium
|Synonym of Rhamphorhynchus muensteri
|-
|Pterodactylus crocodilocephaloides
|Ritgen
|1826
|Synonym of Pterodactylus antiquus
|
|-
|Pterodactylus nettecephaloides
|Ritgen
|1826
|Nomen oblitum
|Synonym of Aurorazhdarcho micronyx
|-
|Pterodactylus macronyx
|Buckland
|1829
|Reclassified as Dimorphodon macronyx
|
|-
|Pterodactylus (Rhamphorhynchus) macronyx
|(Buckland)
|(1829)
|Synonym of Dimorphodon macronyx
|Reclassified from Dimorphodon macronyx
|-
|Pterodactylus banthensis
|(Theodori)
|(1830)
|Reclassified as Dorygnathus banthensis
|Reclassified from Ornithocephalus banthensis
|-
|Pterodactylus (Rhamphorhynchus) (ensirostris) banthensis
|(Theodori)
|(1830)
|Nomen oblitum
|Synonym of Dorygnathus banthensis
|-
|Pterodactylus goldfussi
|Theodori
|1830
|Synonym of Dorygnathus banthensis
|
|-
|Pterodactylus crassirostris
|Goldfuss
|1831
|Reclassified as Scaphognathus crassirostris
|
|-
|Pterodactylus macronyx
|Meyer non Buckland
|1831 non 1829
|Synonym of Dorygnathus banthensis
|
|-
|Pterodactylus medius
|Münster
|1831
|Nomen dubium
|Synonym of Altmuehlopterus rhamphastinus
|-
|Pterodactylus muensteri
|(Goldfuss)
|(1831)
|Synonym of Rhamphorhynchus muensteri
|Reclassified from Ornithocephalus muensteri
|-
|Pterodactylus (Rhamphorhynchus) muensteri
|(Goldfuss)
|(1831)
|Synonym of Rhamphorhynchus muensteri
|Reclassified from Pterodactylus muensteri
|-
|Pterodactylus bucklandi
|Meyer
|1832
|Indeterminate rhamphorhynchine
|Once assigned to the genus Rhamphocephalus
|-
|Pterodactylus longipes
|Münster
|1836
|Synonym of Ardeadactylus longicollum
|
|-
|Pterodactylus kochi
|Wagner
|1837
|Reclassified as Diopecephalus kochi
|Reclassified from Ornithocephalus kochi; possible synonym of Pterodactylus antiquus (Bennett, 2013 The popular aspect of Pterodactylus consists of an elongated head crest, and potentially large wings. Studies of Pterodactylus, however, conclude that it may even lack a bony cranial crest, though several analysis have proven that Pterodactylus may in fact have a crest made up of soft tissue instead of bone.
See also
- List of pterosaur genera
- Timeline of pterosaur research