Anurognathus
Encyclopedia
Anurognathus is a genus
of small pterosaur
that lived approximately 150 million years ago during the late Jurassic
Period (Tithonian
stage).
Anurognathus was first named and described by Ludwig Döderlein in 1923. The type species
is Anurognathus ammoni. The genus name Anurognathus is derived from the Greek
αν/an- ("without"), оυρα/oura ("tail"), and γναθος/gnathos ("jaw") in reference to its unusually small tail relative to other "rhamphorhynchoid
" (i.e. basal) pterosaurs. The specific name ammoni honours the Bavarian geologist Ludwig von Ammon, from whose collection Döderlein had acquired the fossil in 1922.
BSP 1922.I.42 (Bayerische Staatssammlung für Palaeontologie und Geologie), found in the Solnhofen limestone
near Eichstätt
. It consists of a crushed relatively complete skeleton on a slab. The counterslab is missing and with it most of the bones: much of the skeleton is only visible as an impression.
Anurognathus had a short head with pin-like teeth for catching insect
s and although it traditionally is ascribed to the long-tailed pterosaur group "Rhamphorhynchoidea
", its tail was comparatively short, allowing it more maneuverability for hunting. According to Döderlein the reduced tail of Anurognathus was similar to the pygostyle of modern birds. Its more typical "rhamphorhynchoid" characters include its elongated fifth toe and short metacarpals and neck. With an estimated wingspan of fifty centimetres (20 inches) and a nine centimetre long body (skull included), its weight was limited: in 2008 Mark Paul Witton estimated a mass of forty grammes for a specimen with a 35 centimetre wingspan. The holotype was redescribed by Peter Wellnhofer
in 1975.
Later a second, smaller, specimen was found, probably of a subadult individual. Its slab and counterslab are separated and both were sold to private collections; neither has an official registration. It was described by S. Christopher Bennet in 2007. This second exemplar is much more complete and better articulated. It shows impressions of a large part of the flight membrane and under UV-light remains of the muscles of the thigh and arm become visible. It provided new information on many points of the anatomy. The skull was shown to have been very short and broad, wider than long. It transpired that Wellnhofer had incorrectly reconstructed the skull in 1975, mistaking the large eye sockets for the fenestrae antorbitales, skull openings that in most pterosaurs are larger than the orbits but in Anurognathus are small and together with the nostrils placed at the front of the flat snout. The eyes pointed forwards to a degree, providing some binocular vision. Most of the skull consisted of bone struts. The presumed pygostyle was absent; investigating the real nine tail vertebrae instead of impressions showed that they were unfused, though very reduced. The wing finger lacked the fourth phalanx. According to Bennett a membrane, visible near the shin, showed that the wing contacted the ankle and was thus rather short and broad. Bennett also restudied the holotype, interpreting bumps on the jaws as an indication that hairs forming a protruding bristle were present on the snout.
Anurognathus was in 1937 assigned by Oskar Kuhn
to the family
Anurognathid
ae. In the modern clade
Anurognathidae, Anurognathus is the sister taxon of the clade Asiaticognathidae, which contains the species Batrachognathus
, Dendrorhynchoides
and Jeholopterus
.
According to Döderlein Anurognathus was, with its long wings, a swift flyer, surprising its prey, similar to the modern nightjar
. Bennett however, infers from the discovery of the true shorter size of the wings, combined with the short tail, that it was a slower flying predator, specialised in hunting by manoeuvrability, its large eyes adapted to a crepuscular way of life. This would also be proven by a very large flexibility of the wing finger joints.
documentary
series Walking with Dinosaurs
. It was shown having a mutual symbiotic
relationship with the dinosaur
Diplodocus
, eating parasitic
insect
s off its skin
. Such a, purely hypothetical, symbiosis would make it similar to the modern day tick bird
.
Anurognathus was featured in the fifth episode of the ITV
science fiction television series Primeval. Here, Anurognathus was erroneously portrayed as living in the Late Cretaceous period, 85 million years ago, with behavior akin to a piranha
. The producers of the program portrayed Anurognathus as having an amazingly keen sense of smell, able to detect blood from hundreds of feet away. A flock was depicted stripping the flesh from a carcass in a matter of minutes, behavior at odds with anatomical evidence that shows this species to have been insectivorous akin to the modern Frogmouth
. These changes were made for dramatic effect. Anurognathus made a reappearance in the ffth episode of the fifth series.
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 small 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...
that lived approximately 150 million years ago during the late 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 (Tithonian
Tithonian
In the geologic timescale the Tithonian is the latest age of the Late Jurassic epoch or the uppermost stage of the Upper Jurassic series. It spans the time between 150.8 ± 4 Ma and 145.5 ± 4 Ma...
stage).
Anurognathus was first named and described by Ludwig Döderlein in 1923. 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...
is Anurognathus ammoni. The genus name Anurognathus is derived from the Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
αν/an- ("without"), оυρα/oura ("tail"), and γναθος/gnathos ("jaw") in reference to its unusually small tail relative to other "rhamphorhynchoid
Rhamphorhynchoidea
The Rhamphorhynchoidea forms one of the two suborders of pterosaurs and represent an evolutionary grade of primitive members of this group of flying reptiles. This suborder is paraphyletic in relation to the Pterodactyloidea, which arose from within the Rhamphorhynchoidea, not from a more distant...
" (i.e. basal) pterosaurs. The specific name ammoni honours the Bavarian geologist Ludwig von Ammon, from whose collection Döderlein had acquired the fossil in 1922.
Description
The genus is based on holotypeHolotype
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...
BSP 1922.I.42 (Bayerische Staatssammlung für Palaeontologie und Geologie), found in the Solnhofen limestone
Solnhofen limestone
The Solnhofen Plattenkalk is a Jurassic Konservat-Lagerstätte that preserves a rare assemblage of fossilized organisms, including highly detailed imprints of soft bodied organisms such as sea jellies...
near Eichstätt
Eichstätt
Eichstätt is a town in the federal state of Bavaria, Germany, and capital of the District of Eichstätt. It is located along the Altmühl River, at , and had a population of 13,078 in 2002. It is home to the Katholische Universität Eichstätt-Ingolstadt, the lone Catholic university in Germany. The...
. It consists of a crushed relatively complete skeleton on a slab. The counterslab is missing and with it most of the bones: much of the skeleton is only visible as an impression.
Anurognathus had a short head with pin-like teeth for catching insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and although it traditionally is ascribed to the long-tailed pterosaur group "Rhamphorhynchoidea
Rhamphorhynchoidea
The Rhamphorhynchoidea forms one of the two suborders of pterosaurs and represent an evolutionary grade of primitive members of this group of flying reptiles. This suborder is paraphyletic in relation to the Pterodactyloidea, which arose from within the Rhamphorhynchoidea, not from a more distant...
", its tail was comparatively short, allowing it more maneuverability for hunting. According to Döderlein the reduced tail of Anurognathus was similar to the pygostyle of modern birds. Its more typical "rhamphorhynchoid" characters include its elongated fifth toe and short metacarpals and neck. With an estimated wingspan of fifty centimetres (20 inches) and a nine centimetre long body (skull included), its weight was limited: in 2008 Mark Paul Witton estimated a mass of forty grammes for a specimen with a 35 centimetre wingspan. The holotype was redescribed by 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...
in 1975.
Later a second, smaller, specimen was found, probably of a subadult individual. Its slab and counterslab are separated and both were sold to private collections; neither has an official registration. It was described by S. Christopher Bennet in 2007. This second exemplar is much more complete and better articulated. It shows impressions of a large part of the flight membrane and under UV-light remains of the muscles of the thigh and arm become visible. It provided new information on many points of the anatomy. The skull was shown to have been very short and broad, wider than long. It transpired that Wellnhofer had incorrectly reconstructed the skull in 1975, mistaking the large eye sockets for the fenestrae antorbitales, skull openings that in most pterosaurs are larger than the orbits but in Anurognathus are small and together with the nostrils placed at the front of the flat snout. The eyes pointed forwards to a degree, providing some binocular vision. Most of the skull consisted of bone struts. The presumed pygostyle was absent; investigating the real nine tail vertebrae instead of impressions showed that they were unfused, though very reduced. The wing finger lacked the fourth phalanx. According to Bennett a membrane, visible near the shin, showed that the wing contacted the ankle and was thus rather short and broad. Bennett also restudied the holotype, interpreting bumps on the jaws as an indication that hairs forming a protruding bristle were present on the snout.
Anurognathus was in 1937 assigned by Oskar Kuhn
Oskar Kuhn
Oskar Kuhn was a German palaeontologist.-Life and career:Kuhn was educated in Dinkelsbühl and Bamberg and then studied natural science, specialising in geology and paleontology, at the University of Munich, from which he received his D. Phil...
to the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Anurognathid
Anurognathid
The Anurognathidae were a group of small pterosaurs, with short tails or tailless, that lived in Europe and Asia during the Jurassic and early Cretaceous periods...
ae. In the modern clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
Anurognathidae, Anurognathus is the sister taxon of the clade Asiaticognathidae, which contains the species Batrachognathus
Batrachognathus
Batrachognathus is an extinct genus of "rhamphorhynchoid" pterosaur from the Late Jurassic Karabastau Svita of the central Asian republic of Kazakhstan....
, Dendrorhynchoides
Dendrorhynchoides
Dendrorhynchoides was a genus of anurognathid pterosaur from the Early Cretaceous Yixian Formation, near Beipiao, Chaoyang, Liaoning, China...
and Jeholopterus
Jeholopterus
Jeholopterus was a small anurognathid pterosaur from the Daohugou Beds of northeastern China , between 168 and 152 million years ago), preserved with hair and skin remains.-Naming:...
.
According to Döderlein Anurognathus was, with its long wings, a swift flyer, surprising its prey, similar to the modern nightjar
Nightjar
Nightjars are medium-sized nocturnal or crepuscular birds with long wings, short legs and very short bills. They are sometimes referred to as goatsuckers from the mistaken belief that they suck milk from goats . Some New World species are named as nighthawks...
. Bennett however, infers from the discovery of the true shorter size of the wings, combined with the short tail, that it was a slower flying predator, specialised in hunting by manoeuvrability, its large eyes adapted to a crepuscular way of life. This would also be proven by a very large flexibility of the wing finger joints.
In popular culture
Anurognathus was featured in the second episode of the BritishGreat Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
documentary
Documentary film
Documentary films constitute a broad category of nonfictional motion pictures intended to document some aspect of reality, primarily for the purposes of instruction or maintaining a historical record...
series 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...
. It was shown having a mutual symbiotic
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
relationship with the dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
Diplodocus
Diplodocus
Diplodocus , or )is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones...
, eating parasitic
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s off its skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
. Such a, purely hypothetical, symbiosis would make it similar to the modern day tick bird
Yellow-headed Caracara
The Yellow-headed Caracara is a bird of prey in the family Falconidae. It is found in tropical and subtropical South America and the southern portion of Central America...
.
Anurognathus was featured in the fifth episode of the ITV
ITV
ITV is the major commercial public service TV network in the United Kingdom. Launched in 1955 under the auspices of the Independent Television Authority to provide competition to the BBC, it is also the oldest commercial network in the UK...
science fiction television series Primeval. Here, Anurognathus was erroneously portrayed as living in the Late Cretaceous period, 85 million years ago, with behavior akin to a piranha
Piranha
A piranha or piraña is a member of family Characidae in order Characiformes, an omnivorous freshwater fish that inhabits South American rivers. In Venezuela, they are called caribes...
. The producers of the program portrayed Anurognathus as having an amazingly keen sense of smell, able to detect blood from hundreds of feet away. A flock was depicted stripping the flesh from a carcass in a matter of minutes, behavior at odds with anatomical evidence that shows this species to have been insectivorous akin to the modern Frogmouth
Frogmouth
The frogmouths are a group of nocturnal birds related to the nightjars. They are found from India across southern Asia to Australia.They are named for their large flattened hooked bills and huge frog-like gape, which they use to capture insects. Their flight is weak.They rest horizontally on...
. These changes were made for dramatic effect. Anurognathus made a reappearance in the ffth episode of the fifth series.