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Rhamphorhynchus (animal)
Encyclopedia
Rhamphorhynchus "beak snout", is a genus
of long-tailed pterosaur
s in the Jurassic
period. Less specialized than contemporary, short-tailed pterodactyloid pterosaurs such as Pterodactylus
, it had a long tail, stiffened with ligament
s, which ended in a characteristic diamond-shaped vane
. The jaws of Rhamphorhynchus housed needle-like teeth, which were angled forward, with a curved, sharp, beak-like tip lacking teeth, indicating a diet mainly of fish
and insects.
Although fragmentary fossil
remains possibly belonging to Rhamphorhynchus have been found in England
, Tanzania
, and Spain
, the best preserved specimens come from the Solnhofen
limestone of Bavaria
, Germany
. Many of these fossils preserve not only the bones but impressions of soft tissues such as wing membranes. Scattered teeth believed to belong to Rhamphorhynchus have been found in Portugal as well.
The teeth of Rhamphorhynchus intermesh when the jaw is closed and are suggestive of a piscivorous diet. There are twenty teeth in the upper jaws and fourteen in the lower jaws.
of Rhamphorhynchus, like many pterosaur species known since the Victorian era
, is complex, with a long history of reclassification under a variety of names, often for the same specimens.
The first named specimen of Rhamphorhynchus, was brought to the attention of Samuel Thomas von Soemmerring by the collector Georg Graf zu Münster in 1825. von Soermmerring concluded that it belonged to an ancient bird. When further preparation uncovered teeth, Graf zu Münster sent a cast to Professor Georg August Goldfuss
who recognised it as a pterosaur. Like most pterosaurs described in the mid 19th century, Rhamphorhynchus was originally considered to be a species of Pterodactylus
. However, at the time, many scientists incorrectly considered Ornithocephalus to be the valid name for Pterodactylus. This specimen of Rhamphorhynchus was therefore originally named Ornithocephalus Münsteri. This was first mentioned in 1830 by Graf zu Münster himself. However, the description making the name valid was given by Goldfuss in a 1831 follow-up to Münster's short paper. Note that the ICZN
later ruled that non-standard Latin characters such as ü would not be allowed in scientific names, and the spelling münsteri was emended to muensteri by Richard Lydekker
in 1888.
In 1839, Münster described another specimen he considered to belong to Ornithocephalus (i.e. Pterodactylus), with a distinctive long tail. He named it Ornithocephalus longicaudus, meaning "long tail", to differentiate it from the specimens with short tails (the true specimens of Pterodactylus).
In 1845, Hermann von Meyer
officially emended the original species Ornithocephalus münsteri to Pterodactylus münsteri, since the name Pterodactylus had been by that point recognized as having priority over Ornithocephalus. In a subsequent 1846 paper describing a new species of long-tailed 'pterodactyl', von Meyer decided that the long-tailed forms of Pterodactylus were different enough from the short-tailed forms to warrant placement in a subgenus
, and he named his new species Pterodactylus (Rhamphorhynchus) gemmingi after a specimen owned by collector Captain Carl Eming von Gemming that was later by von Gemming sold for three hundred guilders to the Teylers Museum
in Haarlem
. It was not until 1847 that von Meyer elevated Rhamphorhynchus to a full-fledged genus, and officially included in it both long-tailed species of Pterodactylus known at the time, R. longicaudus (the original species preserving a long tail) and R. gemmingi. The type species
of Rhamphorhynchus is R. longicaudus; its type specimen or holotype
also was sold to the Teylers Museum, where it still resides as TM 6924.
The original species, Pterodactylus muensteri, remained misclassified until a re-evaluation was published by Richard Owen
in an 1861 book, in which he renamed it as Rhamphorhynchus münsteri. The type specimen of R. muensteri, described by Münster and Goldfuss, was lost during World War II
. If available, a new specimen or neotype is designated the type if the original is lost or deemed too poorly preserved. Peter Wellnhofer
declined to designate a neotype in his 1975 review of the genus, because a number of high quality casts of the original specimen were still available in museum collections. These can serve as plastotypes.
By the 1990s (and following Wellnfofer's consolidation of many previously named species), about five species of Rhamphorhynchus were recognized from the Solnhofen limestone of Germany, with a few others having been named from Africa, Spain, and the UK based on fragmentary remains. Most of the Solnhofen species were differentiated based on their relative size, and size-related features such as relative length of the skull.
In 1995, pterosaur researcher Chris Bennett published an extensive review of the currently recognized German species. Bennett concluded that all the supposedly distinct German species were actually different year-classes of a single species, R. muensteri, representing distinct age groups, with the smaller species being juveniles and the larger adults. Bennett's paper did not cover the British and African species, though he suggested these should be considered indeterminate members of the family Rhamphorhynchidae
and not necessarily species of Rhamphorhynchus itself. Despite the reduction of the genus to a single species, the type species remains R. longicaudus.
Juvenile Rhamphorhynchus had relatively short skulls with large eyes, and the toothless beak-like tips of the jaws were shorter in juveniles than adults, with rounded, blunt lower jaw tips eventually becoming slender and pointed as the animals grew. Adult Rhamphorhynchus also developed a strong upward "hook" at the end of the lower jaw. The number of teeth remained constant from juvenile to adult, though the teeth became relatively shorter and stockier as the animals grew, possibly to accommodate larger and more powerful prey. The pelvic and pectoral girdles fused as the animals aged, with full pectoral fusion attained by one year of age.
The shape of the tail vane also changed across various age classes of Rhamphorhynchus. In juveniles, the vane was shallow relative to the tail and roughly oval, or "lancet
-shaped". As growth progressed, the tail vane became diamond
-shaped, and finally triangular
in the largest individuals.
The smallest known Rhamphorhynchus specimen has a wingspan of only 290 millimeters; however, it is likely that even such a small individual was capable of flight. Bennett examined two possibilities for hatchlings: that they were altricial
, requiring some period of parental care before leaving the nest, or that they were precocial
, hatching with sufficient size and ability for flight. If precocious, Bennett suggested that clutches would be small, with only one or two eggs laid per clutch, to compensate for the relatively large size of the hatchings. Bennett did not speculate on which possibility was more likely, though the discovery of a pterosaur embryo (Avgodectes
) with strongly ossified bones suggests that pterosaurs in general were precocial, able to fly soon after hatching with minimal parental care.
s. Growth likely slowed considerably after sexual maturity, so it would have taken more than three years to attain maximum adult size.
This growth rate is much slower than the rate seen in large pterodactyloid pterosaurs such as Pteranodon
, which attained near-adult size within the first year of life. Additionally, pterodactyloids had determinate growth, meaning that the animals reached a fixed maximum adult size and stopped growing. Previous assumptions of rapid growth rate in rhamphorhynchoids were based on the assumption that they needed to be warm-blooded
to sustain active flight. Warm-blooded animals, like modern bird
s and bat
s, normally show rapid growth to adult size and determinate growth. Because there is no evidence for either in Rhamphorhynchus, Bennett considered his findings consistent with an ectotherm
ic metabolism, though he recommended more studies needed to be done. Cold-blooded Rhamphorhynchus, Bennett suggested, may have basked in the sun or worked their muscles to accumulate enough energy for bouts of flight, and cooled to ambient temperature when not active to save energy, like modern reptile
s.
recognized two distinct groups among adult Rhamphorhynchus muensteri, differentiated by the proportions of the neck, wing, and hind limbs, but particularly in the ratio of skull to humerus
length. Both researchers noted that these two groups of specimens were found in roughly a 1:1 ratio, and interpreted them as different sexes. Bennett tested for sexual dimorphism in Rhamphorhynchus by using a statistical analysis, and found that the specimens did indeed group together into small-headed and large-headed sets. However, without any known variation in the actual form of the bones or soft tissue (morphological differences), he found the case for sexual dimorphism inconclusive.
studied the brain anatomy of several types of pterosaurs, including Rhamphorhynchus muensteri, using endocasts of the brain they retrieved by performing CAT scans of fossil skulls. Using comparisons to modern animals, they were able to estimate various physical attributes of pterosaurs, including relative head orientation during flight and coordination of the wing membrane muscles. Witmer and his team found that Rhamphorhynchus held its head parallel to the ground due to the orientation of the osseous labyrinth of the inner ear
, which helps animals detect balance. In contrast, pterodactyloid pterosaurs such as Anhanguera
appear to have normally held their heads at a downward angle, both in flight and while on the ground.
s of Rhamphorhynchus and modern birds and reptiles suggest that it may have been nocturnal, and may have had activity patterns similar to those of modern nocturnal seabirds. This may also indicate niche partitioning with contemporary pterosaurs inferred to be diurnal, such as Scaphognathus
and Pterodactylus
.
Note that Rhamphorhynchus
is also a genus of orchid, named in 1977 by botanist L.A. Garay. In biological nomenclature, the same name may be used for an animal
that has already been used for a plant
or vice versa.
Synonyms of Rhamphorhynchus muensteri:
a skull with lower jaw that is now lost. This set of jaws supposedly differed in having two teeth united at the tip of the lower jaw, and none at the tip of the upper jaw. The skull was 6.5–7.0 cm (2.56–2.76 in), making it a small form. Stolley, who described the specimen in 1936, argued that R. longicaudus also should be reclassified in the genus "Odontorhynchus". Both Koh and Wellnhofer rejected this idea, arguing instead that "Odontorhynchus" was a junior synonym of R. longicaudus. Bennett agreed with their assessments, and included both "Odontorhynchus" and R. longicaudus as synonyms of R. muensteri.
novels by Edgar Rice Burroughs
are a race of giant telepathic Rhamphorhynchus called Mahars. They use Sagoths, a race of gorilla-like people, to collect humans for slavery, sport, and food.
Rhamphorhynchus was featured in the third episode "Cruel Sea" of the British Walking with Dinosaurs
television series. The reptile is shown living amongst the seaside hunting fish, digging for horseshoe crab
eggs and stripping bark off conifer trees to find bark beetle
larva
e. It is also shown being hunted by Eustreptospondylus
.
It also appeared in the 1971 film When Dinosaurs Ruled the Earth
.
In the 1977 Japanese monster movie Legend of Dinosaurs & Monster Birds
, a plesiosaur
and an oversized Rhamphorhynchus terrorize the people around Mt. Fuji until they meet and do battle to the death amidst a volcanic eruption.
In The Land Before Time VII there is a sinister Rhamphorhynchus named Rinkus.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of long-tailed pterosaur
Pterosaur
Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...
s in the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
period. Less specialized than contemporary, short-tailed pterodactyloid pterosaurs such as Pterodactylus
Pterodactylus
Pterodactylus is a genus of pterosaurs, whose members are popularly known as pterodactyls. It was the first to be named and identified as a flying reptile...
, it had a long tail, stiffened with ligament
Ligament
In anatomy, the term ligament is used to denote any of three types of structures. Most commonly, it refers to fibrous tissue that connects bones to other bones and is also known as articular ligament, articular larua, fibrous ligament, or true ligament.Ligament can also refer to:* Peritoneal...
s, which ended in a characteristic diamond-shaped vane
Vane
Vane may refer to:* Cooper vane* Vane anemometer* Weather vaneA vane is also each of the parts besides the shaft in a pennaceous feather...
. The jaws of Rhamphorhynchus housed needle-like teeth, which were angled forward, with a curved, sharp, beak-like tip lacking teeth, indicating a diet mainly of fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
and insects.
Although fragmentary fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
remains possibly belonging to Rhamphorhynchus have been found in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
, and Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
, the best preserved specimens come from the Solnhofen
Solnhofen
Solnhofen is a municipality in the district of Weißenburg-Gunzenhausen in the region of Franconia in the Land of Bavaria in Germany. It lies within the Altmühl valley....
limestone of Bavaria
Bavaria
Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
. Many of these fossils preserve not only the bones but impressions of soft tissues such as wing membranes. Scattered teeth believed to belong to Rhamphorhynchus have been found in Portugal as well.
Description
The largest known specimen of Rhamphorhynchus muensteri (catalog number BMNH 37002) measures 1.26 meters (4.1 ft) long with a wingspan of 1.81 m (5.9 ft).Skull
Contrary to a 1927 report by pterosaur researcher Ferdinand Broili, Rhamphorhynchus lacked any bony or soft tissue crest, as seen in several species of contemporary small pterodactyloid pterosaurs. Broili claimed to have found a two millimeter tall crest made of thin bone that ran much of the skulls length in one Rhamphorhynchus specimen, evidenced by an impression in the surrounding rock and a few small fragments of the crest itself. However, subsequent examination of this specimen by Wellnhofer in 1975 and Bennett in 2002 using both visible and ultraviolet light found no trace of a crest, and both concluded that Broili was mistaken. The supposed crest, they concluded, was simply an artifact of preservation.The teeth of Rhamphorhynchus intermesh when the jaw is closed and are suggestive of a piscivorous diet. There are twenty teeth in the upper jaws and fourteen in the lower jaws.
History and classification
The classification and taxonomyTaxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
of Rhamphorhynchus, like many pterosaur species known since the Victorian era
Victorian era
The Victorian era of British history was the period of Queen Victoria's reign from 20 June 1837 until her death on 22 January 1901. It was a long period of peace, prosperity, refined sensibilities and national self-confidence...
, is complex, with a long history of reclassification under a variety of names, often for the same specimens.
The first named specimen of Rhamphorhynchus, was brought to the attention of Samuel Thomas von Soemmerring by the collector Georg Graf zu Münster in 1825. von Soermmerring concluded that it belonged to an ancient bird. When further preparation uncovered teeth, Graf zu Münster sent a cast to Professor Georg August Goldfuss
Georg August Goldfuss
Georg August Goldfuss was a German palaeontologist and zoologist.-Biography:Goldfuss was born at Thurnau near Bayreuth. He was educated at Erlangen, where he graduated Ph.D. in 1804 and became professor of zoology in 1818. He was subsequently appointed professor of zoology and mineralogy at the...
who recognised it as a pterosaur. Like most pterosaurs described in the mid 19th century, Rhamphorhynchus was originally considered to be a species of Pterodactylus
Pterodactylus
Pterodactylus is a genus of pterosaurs, whose members are popularly known as pterodactyls. It was the first to be named and identified as a flying reptile...
. However, at the time, many scientists incorrectly considered Ornithocephalus to be the valid name for Pterodactylus. This specimen of Rhamphorhynchus was therefore originally named Ornithocephalus Münsteri. This was first mentioned in 1830 by Graf zu Münster himself. However, the description making the name valid was given by Goldfuss in a 1831 follow-up to Münster's short paper. Note that the ICZN
International Commission on Zoological Nomenclature
The International Commission on Zoological Nomenclature is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 28 members from 20 countries, mainly practicing zoological taxonomists...
later ruled that non-standard Latin characters such as ü would not be allowed in scientific names, and the spelling münsteri was emended to muensteri by Richard Lydekker
Richard Lydekker
Richard Lydekker was an English naturalist, geologist and writer of numerous books on natural history.-Biography:...
in 1888.
In 1839, Münster described another specimen he considered to belong to Ornithocephalus (i.e. Pterodactylus), with a distinctive long tail. He named it Ornithocephalus longicaudus, meaning "long tail", to differentiate it from the specimens with short tails (the true specimens of Pterodactylus).
In 1845, Hermann von Meyer
Christian Erich Hermann von Meyer
Christian Erich Hermann von Meyer was a German palaeontologist.He was born at Frankfurt am Main.In 1832 von Meyer issued a work entitled Palaeologica, and in course of time he published a series of memoirs on various fossil organic remains: molluscs, crustaceans, fishes and higher vertebrata,...
officially emended the original species Ornithocephalus münsteri to Pterodactylus münsteri, since the name Pterodactylus had been by that point recognized as having priority over Ornithocephalus. In a subsequent 1846 paper describing a new species of long-tailed 'pterodactyl', von Meyer decided that the long-tailed forms of Pterodactylus were different enough from the short-tailed forms to warrant placement in a subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
, and he named his new species Pterodactylus (Rhamphorhynchus) gemmingi after a specimen owned by collector Captain Carl Eming von Gemming that was later by von Gemming sold for three hundred guilders to the Teylers Museum
Teylers Museum
Teyler's Museum , located in Haarlem, is the oldest museum in the Netherlands. The museum is in the former home of Pieter Teyler van der Hulst . He was a wealthy cloth merchant and Amsterdam banker of Scottish descent, who bequeathed his fortune for the advancement of religion, art and science...
in Haarlem
Haarlem
Haarlem is a municipality and a city in the Netherlands. It is the capital of the province of North Holland, the northern half of Holland, which at one time was the most powerful of the seven provinces of the Dutch Republic...
. It was not until 1847 that von Meyer elevated Rhamphorhynchus to a full-fledged genus, and officially included in it both long-tailed species of Pterodactylus known at the time, R. longicaudus (the original species preserving a long tail) and R. gemmingi. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of Rhamphorhynchus is R. longicaudus; its type specimen or holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
also was sold to the Teylers Museum, where it still resides as TM 6924.
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
in an 1861 book, in which he renamed it as Rhamphorhynchus münsteri. The type specimen of R. muensteri, described by Münster and Goldfuss, was lost during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. If available, a new specimen or neotype is designated the type if the original is lost or deemed too poorly preserved. Peter Wellnhofer
Peter Wellnhofer
Peter Wellnhofer is a German paleontologist at the "Bayerische Staatssammlung fur Paläontologie" in Munich. He is best known for his work on the various fossil specimens of Archaeopteryx or "Urvogel", the first known bird...
declined to designate a neotype in his 1975 review of the genus, because a number of high quality casts of the original specimen were still available in museum collections. These can serve as plastotypes.
In 1995, pterosaur researcher Chris Bennett published an extensive review of the currently recognized German species. Bennett concluded that all the supposedly distinct German species were actually different year-classes of a single species, R. muensteri, representing distinct age groups, with the smaller species being juveniles and the larger adults. Bennett's paper did not cover the British and African species, though he suggested these should be considered indeterminate members of the family Rhamphorhynchidae
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.-Classification:...
and not necessarily species of Rhamphorhynchus itself. Despite the reduction of the genus to a single species, the type species remains R. longicaudus.
Life history
Traditionally, the large size variation between specimens of Rhamphorhynchus has been taken to represent species variation. However, in a 1995 paper, Bennett argued that these "species" actually represent year-classes of a single species, Rhamphorhynchus muensteri, from flaplings to adults. Following from this interpretation, Bennett found several notable changes that occurred in R. muensteri as the animal aged.Juvenile Rhamphorhynchus had relatively short skulls with large eyes, and the toothless beak-like tips of the jaws were shorter in juveniles than adults, with rounded, blunt lower jaw tips eventually becoming slender and pointed as the animals grew. Adult Rhamphorhynchus also developed a strong upward "hook" at the end of the lower jaw. The number of teeth remained constant from juvenile to adult, though the teeth became relatively shorter and stockier as the animals grew, possibly to accommodate larger and more powerful prey. The pelvic and pectoral girdles fused as the animals aged, with full pectoral fusion attained by one year of age.
Scalpel
A scalpel, or lancet, is a small and extremely sharp bladed instrument used for surgery, anatomical dissection, and various arts and crafts . Scalpels may be single-use disposable or re-usable. Re-usable scalpels can have attached, resharpenable blades or, more commonly, non-attached, replaceable...
-shaped". As growth progressed, the tail vane became diamond
Rhomboid
Traditionally, in two-dimensional geometry, a rhomboid is a parallelogram in which adjacent sides are of unequal lengths and angles are oblique.A parallelogram with sides of equal length is a rhombus but not a rhomboid....
-shaped, and finally triangular
Triangle
A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted ....
in the largest individuals.
The smallest known Rhamphorhynchus specimen has a wingspan of only 290 millimeters; however, it is likely that even such a small individual was capable of flight. Bennett examined two possibilities for hatchlings: that they were altricial
Altricial
Altricial, meaning "requiring nourishment", refers to a pattern of growth and development in organisms which are incapable of moving around on their own soon after hatching or being born...
, requiring some period of parental care before leaving the nest, or that they were precocial
Precocial
In biology, the term precocial refers to species in which the young are relatively mature and mobile from the moment of birth or hatching. The opposite developmental strategy is called "altricial," where the young are born or hatched helpless. Extremely precocial species may be called...
, hatching with sufficient size and ability for flight. If precocious, Bennett suggested that clutches would be small, with only one or two eggs laid per clutch, to compensate for the relatively large size of the hatchings. Bennett did not speculate on which possibility was more likely, though the discovery of a pterosaur embryo (Avgodectes
Avgodectes
Avgodectes is a controversial pterosaur genus. The full binomial is Avgodectes pseudembryon, which translates to "false-embryo egg-biter"; avgo is taken from modern Greek for "egg". Named by David Peters in 2004 and based on a pterosaur found within an egg...
) with strongly ossified bones suggests that pterosaurs in general were precocial, able to fly soon after hatching with minimal parental care.
Metabolism
Having determined that Rhamphorhynchus specimens fit into discrete year-classes, Bennett was able to estimate growth rate during one year by comparing the size of one-year-old specimens with two-year-old specimens. He found that the average growth rate during the first year of life for Rhamphorhynchus was 130% to 173%, slightly faster than the growth rate in alligatorAlligator
An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. There are two extant alligator species: the American alligator and the Chinese alligator ....
s. Growth likely slowed considerably after sexual maturity, so it would have taken more than three years to attain maximum adult size.
This growth rate is much slower than the rate seen in large pterodactyloid pterosaurs such as Pteranodon
Pteranodon
Pteranodon , from the Late Cretaceous geological period of North America in present day Kansas, Alabama, Nebraska, Wyoming, and South Dakota, was one of the largest pterosaur genera and had a maximum wingspan of over...
, which attained near-adult size within the first year of life. Additionally, pterodactyloids had determinate growth, meaning that the animals reached a fixed maximum adult size and stopped growing. Previous assumptions of rapid growth rate in rhamphorhynchoids were based on the assumption that they needed to be warm-blooded
Warm-blooded
The term warm-blooded is a colloquial term to describe animal species which have a relatively higher blood temperature, and maintain thermal homeostasis primarily through internal metabolic processes...
to sustain active flight. Warm-blooded animals, like modern bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s and bat
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
s, normally show rapid growth to adult size and determinate growth. Because there is no evidence for either in Rhamphorhynchus, Bennett considered his findings consistent with an ectotherm
Ectotherm
An ectotherm, from the Greek εκτός "outside" and θερμός "hot", refers to organisms that control body temperature through external means. As a result, organisms are dependent on environmental heat sources and have relatively low metabolic rates. For example, many reptiles regulate their body...
ic metabolism, though he recommended more studies needed to be done. Cold-blooded Rhamphorhynchus, Bennett suggested, may have basked in the sun or worked their muscles to accumulate enough energy for bouts of flight, and cooled to ambient temperature when not active to save energy, like modern reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s.
Sexual dimorphism
Both Koh Ting-Pong and Peter WellnhoferPeter Wellnhofer
Peter Wellnhofer is a German paleontologist at the "Bayerische Staatssammlung fur Paläontologie" in Munich. He is best known for his work on the various fossil specimens of Archaeopteryx or "Urvogel", the first known bird...
recognized two distinct groups among adult Rhamphorhynchus muensteri, differentiated by the proportions of the neck, wing, and hind limbs, but particularly in the ratio of skull to humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
length. Both researchers noted that these two groups of specimens were found in roughly a 1:1 ratio, and interpreted them as different sexes. Bennett tested for sexual dimorphism in Rhamphorhynchus by using a statistical analysis, and found that the specimens did indeed group together into small-headed and large-headed sets. However, without any known variation in the actual form of the bones or soft tissue (morphological differences), he found the case for sexual dimorphism inconclusive.
Head orientation
In 2003, a team of researchers led by Lawrence WitmerLawrence Witmer
Lawrence Witmer is an American paleontologist. He is a Professor of Anatomy and a Chang Ying-Chien Professor of Paleontology at the Department of Biomedical Sciences at the College of Osteopathic Medicine in Ohio University. Witmer is considered to be one of the world's foremost Armchair...
studied the brain anatomy of several types of pterosaurs, including Rhamphorhynchus muensteri, using endocasts of the brain they retrieved by performing CAT scans of fossil skulls. Using comparisons to modern animals, they were able to estimate various physical attributes of pterosaurs, including relative head orientation during flight and coordination of the wing membrane muscles. Witmer and his team found that Rhamphorhynchus held its head parallel to the ground due to the orientation of the osseous labyrinth of the inner ear
Inner ear
The inner ear is the innermost part of the vertebrate ear. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts:...
, which helps animals detect balance. In contrast, pterodactyloid pterosaurs such as Anhanguera
Anhanguera (pterosaur)
Anhanguera is a genus of pterodactyloid pterosaur known from the Lower-Cretaceous Santana Formation of Brazil, with referred specimens found in the Upper Chalk Formation and Cambridge Greensand of the UK...
appear to have normally held their heads at a downward angle, both in flight and while on the ground.
Daily activity patterns
Comparisons between the scleral ringSclerotic ring
Sclerotic rings are rings of bone found in the eyes of several groups of vertebrate animals, except for mammals and crocodilians. They can be made up of single bones or small bones together. They are believed to have a role in supporting the eye, especially in animals whose eyes are not spherical,...
s of Rhamphorhynchus and modern birds and reptiles suggest that it may have been nocturnal, and may have had activity patterns similar to those of modern nocturnal seabirds. This may also indicate niche partitioning with contemporary pterosaurs inferred to be diurnal, such as Scaphognathus
Scaphognathus
Scaphognathus was a pterosaur that lived around Germany during the Late Jurassic. It had a wingspan of about one meter.-Naming:The first known Scaphognathus specimen was described in 1831 by August Goldfuss who mistook the tailless specimen for a new Pterodactylus species: P. crassirostris. The...
and Pterodactylus
Pterodactylus
Pterodactylus is a genus of pterosaurs, whose members are popularly known as pterodactyls. It was the first to be named and identified as a flying reptile...
.
Species
A large number of Rhamphorhynchus species have been named, but are currently considered year-classes of R. muensteri by most researchers. Currently recognized specimens of Rhamphorhynchus have previously been published on under the following junior synonyms:Note that Rhamphorhynchus
Rhamphorhynchus (orchid)
Aspidogyne mendoncae is a species of orchid that grows in Brazil.-Biology:Aspidogyne mendoncae grows in humus on the floor of lowland forests, in the Brazilian state of Espirito Santo.-Taxonomic history:...
is also a genus of orchid, named in 1977 by botanist L.A. Garay. In biological nomenclature, the same name may be used for an animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
that has already been used for a plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
or vice versa.
Synonyms
Synonyms of Rhamphorhynchus muensteri:
- Ornithocephalus muensteri Goldfuss, 1831 emend. Lydekker, 1888
- Pterodactylus muensteri Goldfuss, 1831 emend. Lydekker, 1888
- Pterodactylus (Rhamphorhynchus) muensteri (Goldfuss, 1831)
- R. longicaudus (Münster, 1839) von Meyer, 1846
- Pterodactylus longicaudus Münster, 1839
- Odontorhynchus longicaudus (Münster, 1839) Olshevsky, 1978
- Ornithocephalus longicaudus (Münster, 1839) Wagner, 1851
- Rhamphorhynchus (Odontorhynchus) longicaudus (Münster, 1839) Stolley, 1936
- R. gemmingi (von Meyer, 1846) von Meyer, 1855
- Pterodactylus lavateri von Meyer, 1838a
- Ornithopterus lavateri (von Meyer, 1838a) von Meyer, 1838b
- Pterodactylus gemmingi von Meyer, 1846
- Pterodactylus (Rhamphorhynchus) gemmingi von Meyer, 1846
- Pterodactylus (Ornithopterus) lavateri (von Meyer, 1838a) Owen, 1851
- Ornithocephalus gemmingi (von Meyer, 1846) Wagner, 1851
- Rhamphorhynchus (Pterodactylus) gemmingi (von Meyer, 1846) von Meyer, 1855
- R. suevicus O. Fraas, 1855
- Pterodactylus hirundinaceus Wagner, 1857
- Pterodactylus (Rhamphorhynchus) hirundinaceus Wagner, 1857
- R. hirundinaceus (Wagner, 1857) Wagner, 1858
- R. curtimanus Wagner, 1858
- R. longimanus Wagner, 1858
- R. meyeri Owen, 1870
- R. phyllurus Marsh, 1882
- Pteromonodactylus phyllurus (Marsh, 1882) Teryaev, 1967
- R. longiceps Woodward, 1902
- Ornithocephalus giganteus Oken, 1819
- Pterodactylus giganteus (Oken, 1819)
- Pterodactylus grandis Cuvier, 1824
- Ornithocephalus grandis (Cuvier, 1824) Wagner, 1851
- R. grandis (Cuvier, 1824) Lydekker, 1888
- Pterodactylus secundarius von Meyer, 1843
- Ornithocephalus secundarius (von Meyer, 1843) Wagner, 1851
- R. kokeni F. Plieninger, 1907
- R. megadactylus von Koenigswald, 1931
- R. carnegiei Koh, 1937
Dubious species
Dubious species of Rhamphorhynchus:- R. jessoni (Lydekker, 1890)
- R. tendagurensis (Peck, 1931)
- R. intermedius Koh, 1937
- R. intermedius var. brevialata Koh, 1937
"Odontorhynchus"
"Odontorhynchus" aculeatus was based onHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
a skull with lower jaw that is now lost. This set of jaws supposedly differed in having two teeth united at the tip of the lower jaw, and none at the tip of the upper jaw. The skull was 6.5–7.0 cm (2.56–2.76 in), making it a small form. Stolley, who described the specimen in 1936, argued that R. longicaudus also should be reclassified in the genus "Odontorhynchus". Both Koh and Wellnhofer rejected this idea, arguing instead that "Odontorhynchus" was a junior synonym of R. longicaudus. Bennett agreed with their assessments, and included both "Odontorhynchus" and R. longicaudus as synonyms of R. muensteri.
In popular culture
The main villains of the first two PellucidarPellucidar
Pellucidar is a fictional Hollow Earth milieu invented by Tarzan creator Edgar Rice Burroughs for a series of action adventure stories. In a notable crossover event between Burroughs' series, there is a Tarzan story in which the Ape Man travels into Pellucidar.The stories initially involve the...
novels by Edgar Rice Burroughs
Edgar Rice Burroughs
Edgar Rice Burroughs was an American author, best known for his creation of the jungle hero Tarzan and the heroic Mars adventurer John Carter, although he produced works in many genres.-Biography:...
are a race of giant telepathic Rhamphorhynchus called Mahars. They use Sagoths, a race of gorilla-like people, to collect humans for slavery, sport, and food.
Rhamphorhynchus was featured in the third episode "Cruel Sea" of the British Walking with Dinosaurs
Walking with Dinosaurs
Walking with Dinosaurs is a six-part documentary television miniseries that was produced by BBC, narrated by Kenneth Branagh, and first aired in the United Kingdom, in 1999. The series was subsequently aired in North America on the Discovery Channel in 2000, with Branagh's voice replaced with that...
television series. The reptile is shown living amongst the seaside hunting fish, digging for horseshoe crab
Horseshoe crab
The Atlantic horseshoe crab, Limulus polyphemus, is a marine chelicerate arthropod. Despite its name, it is more closely related to spiders, ticks, and scorpions than to crabs. Horseshoe crabs are most commonly found in the Gulf of Mexico and along the northern Atlantic coast of North America...
eggs and stripping bark off conifer trees to find bark beetle
Bark beetle
A bark beetle is one of approximately 220 genera with 6,000 species of beetles in the subfamily Scolytinae. Traditionally, this was considered a distinct family Scolytidae, but now it is understood that bark beetles are in fact very specialized members of the "true weevil" family...
larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e. It is also shown being hunted by Eustreptospondylus
Eustreptospondylus
Eustreptospondylus is a genus of megalosaurid dinosaur, from the Callovian stage of the Middle Jurassic period in southern England, at a time when Europe was a series of scattered islands Eustreptospondylus ("well-curved vertebra", in reference to the arrangement of the spine in the original...
.
It also appeared in the 1971 film When Dinosaurs Ruled the Earth
When Dinosaurs Ruled the Earth
When Dinosaurs Ruled the Earth is a 1970 movie starring Victoria Vetri, set in the time of cavemen. The film was made by Britain's Hammer Films....
.
In the 1977 Japanese monster movie Legend of Dinosaurs & Monster Birds
Legend of Dinosaurs & Monster Birds
is a Japanese science fiction film, released by Toei Company. The film featured a giant Plesiosaur and Rhamphorhynchus....
, a plesiosaur
Plesiosaur
Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...
and an oversized Rhamphorhynchus terrorize the people around Mt. Fuji until they meet and do battle to the death amidst a volcanic eruption.
In The Land Before Time VII there is a sinister Rhamphorhynchus named Rinkus.