| Name | Anurognathus | Diet | Insectivore |
| Name Meaning | “Without Tail Jaw” | Height | 50 centimeters (20 inches) |
| Pronunciation | An-yu-roe-nath-us | Length | 9 meters (30 feet) |
| Era | Mesozoic – Late Jurassic | Weight | 40 grams (1.4 oz) |
| Classification | Archosauromorpha, Pterosauria & Rhamphorhynchoidea | Location | Germany (Europe) |
Anurognathus Pictures
The Anurognathus
Pterosaurs were flying reptiles that were quite common throughout the Mesozoic Era.
They came in different shapes and sizes, from airplane-sized species to smaller ones that were about the size of modern bats.
Anurognathus was on the smaller end of the spectrum.
The big-eyed pterosaur lived in Germany during the Late Jurassic Period about 149 million years ago.
It was among the smallest and oddest flying reptiles ever found.
The genus “Anurognathus” translates as “without tail and jaws.”
This is a reference to the tail of this dinosaur which is unusually small compared to those of its relatives in the rhamphorhynchoid group.
In addition to the unusual body proportions of this pterosaur, there are other interesting details about it, such as its big eyes, short rounded skull, and broad wings.
In this article, we explore all the fascinating details of this pterosaur’s appearance, lifestyle, and how it lived.
Physical Characteristics
Anurognathus was a relatively small pterosaur and very much unlike any of its contemporaries.
With a wingspan of just 50 centimeters (20 inches) and a nine-centimeter-long body, it is arguably one of the smallest flying reptiles ever found.
The length of this pterosaur’s body includes the length of its unusually large head.
The total weight of the Anurognathus has been estimated to be about 40 grams (1.4 oz).
Anurognathus had a compact and slender body.
The skull was disproportionately large for such a tiny creature, and it had unusually large eyes, too.
Its body was relatively short, and it had elongated hind limbs that would have helped to maintain stability during flight.
Like other pterosaurs, the Anurognathus’ wings were formed by a membrane of skin that stretched between its elongated fourth finger and the body, enabling powered flight.
Anurognathus had elongated jaws that were filled with sharp, pointed teeth. This dental structure suggests that this pterosaur was well-adapted to an insectivore diet.
Scientists have found little bumps around the jaw of this pterosaur.
These bumps were most likely the root of bristles or whiskers, which may have helped sense prey.
The wings of the Anurognathus were also covered with furry microfilaments or pycnofibers.
Although this is seen in other flying reptiles, the filaments on the wings of the Anurognathus were particularly fuzzy.
Experts think they helped dampen the sound their wings produced during flight.
Another distinct feature of the Anurognathus was its unusually short tail.
Although a member of the rhamphorhynchoid pterosaur group (known for their long tails), the Anurognathus’ tail was short, unlike those of its relatives.
The tailbones have been found to be similar to modern birds, giving the pterosaur more maneuverability during flight.
Habitat and Distribution
Anurognathus lived during the Late Jurassic Period in what is now Europe.
More specifically, fossils of this pterosaur have been found in Germany.
Its geographic range suggests that Anurognathus lived in a part of the ancient supercontinent called Laurasia.
During the Late Jurassic, Laurasia had a warm and humid climate, and the region experienced seasonal variations.
During this period, the supercontinent Pangea was starting to break up, forming separate land masses with distinct ecosystems.
Fossils of Anurognathus were found in the Solnhofen Limestone Formation, a famous rock bed known to preserve remains of various island species that lived during the Jurassic Period.
The local ecosystem of this region is quite similar to that of present-day Bahamas.
It was made up of a string of low-lying islands with warm shallow seas separating them.
Parts of this island chain were dry and rocky, but some areas were covered by sparse vegetation.
Anurognathus likely inhabited forested environments, particularly areas near bodies of water such as lakes, rivers, or swamps.
These habitats would have provided an abundant food supply in the form of insects, which formed the primary diet of Anurognathus.
Forested areas also provided ample cover for the Anurognathus while hunting or nesting.
Behavior and Diet
Anurognathus was a pterosaur and possessed adaptations for powered flight.
The lifestyle of the Anurognathus is often compared to other small flying insect hunters such as bats and swallows.
As a pterosaur, this reptile had narrow wings and was quite agile.
They flew actively, and their flight style is often compared to that of acrobatic bird species like swifts and martins.
The elongated hind limbs of this flying reptile may have provided additional stability during flight.
It also had the ability to perch on tree branches and other surfaces when at rest, like modern birds.
It is possible that the Anurognathus exhibited some level of social interaction, but there’s no direct evidence for this.
Some pterosaurs have been found in groups in certain fossil sites, which suggests that at least some of these flying reptiles were social, nesting or roosting in colonies like modern bats.
Anurognathus was an insectivorous pterosaur, which means it primarily fed on insects.
It had elongated jaws with sharp teeth specially adapted for capturing insects while in flight.
Anurognathus had huge eyes that were perfectly adapted for seeing in low-light conditions.
The forward-facing eyes provided some depth perception which is common in animals with binocular vision.
Scientists think the Anurognathus lived a crepuscular lifestyle, meaning they were most active during low light conditions such as dusk or dawn.
To obtain food, Anurognathus likely used a wide range of hunting techniques, including aerial hunting or snatching insects close while perching on branches or other surfaces.
Its excellent eyesight would have made spotting and capturing flying insects easier.
Life Cycle
Based on what is known about the reproduction and lifecycle of other pterosaurs and reptiles, we can infer some things about the reproductive behavior of the Anurognathus.
Like other reptiles, it reproduced sexually, laying eggs instead of giving birth to live young.
However, the exact nesting habits of this flying reptile aren’t known. It is also unclear if they exhibited parental care or not.
They most likely laid their eggs in protected burrows or nests but did not brood like modern birds.
After hatching, young Anurognathus hatchlings would have been young and vulnerable, probably requiring some parental care to get food and ensure their survival.
In one study, scientists found that the growth rate of young pterosaurs was faster than that of modern birds.
This suggests that they were less dependent on their parents and were able to fly sooner than their modern flying relatives.
They may have exhibited accelerated growth rates, reaching maturity relatively quickly. After reaching maturity, pterosaurs grew slowly.
One study found that these flying reptiles gained just 0.03 ounces (one gram) a day. It would have taken them several years to reach full maturity.
Evolution and History
Anurognathus was a flying reptile or pterosaur.
These flying reptiles were quite dominant throughout the Mesozoic Era and came in different shapes and forms.
The pterosaur order was divided into two suborders representing two different evolutionary grades.
The older or more primitive group was called Rhamphorhynchoidea, while the younger group was called the Pterodactyloidea.
Members of the latter group evolved directly from the Rhamphorhynchoidea suborder.
Part of what makes the Anurognathus such an interesting pterosaur is the fact that it shows features that are sort of intermediate between these two groups.
Although it is a member of the basal group, the absence of a long tail, the most distinct feature of the rhamphorhynchoid pterosaurs, makes it quite odd.
Experts think the lack of tail was an acquired trait that the Anurognathus and its closest relatives (the anurognathids) picked up as they evolved.
The short tail of the Anurognathus was more beneficial for maneuverability while hunting.
The pterosaur evolved other unique adaptations relevant to its ecological role as an insectivore.
This includes their broad wings, which would have made it easier to maneuver in the air as well as their sharp, needle-like teeth that helped with catching prey.
They also had furry filaments on their feathers that helped silence their wings while in flight, an adaptation also seen in owls and other hunting birds.
The anurognathids were among the last of the rhamphorhynchoids alive.
Most members of this basal group went extinct by the end of the Jurassic Period, but the anurognathids survived till the Early Cretaceous Period.
Interactions With Other Species
Despite its size, this tiny pterosaur was an accomplished insect hunter.
It targeted a variety of insects, such as beetles, flies, and other flying arthropods.
But the Anurognathus itself was probably hunted by larger pterosaurs, too, such as Rhamphorhynchus.
Some small to medium-sized carnivorous dinosaurs may opportunistically prey on small pterosaurs like Anurognathus.
This pterosaur’s crepuscular hunting habit would have made it easier to access prey while also ensuring that it stayed out of the way of larger pterosaurs that were more active during the day or at night.
In addition to their ability to glide silently, Anurognathus may have used other strategies to make itself invisible to predators.
Fossils of this pterosaur were often found with their wings folded against their body.
Scientists think they flattened their bodies against tree branches, leaves, and other solid surfaces this way to stay hidden from predators.
Cultural Significance
Natural History Museum in Karlsruhe | Ghedoghedo via Wikipedia (CC BY-SA 4.0)
Fossils of the Anurognathus are rare.
They’re only found in sites known for exceptional fossil preservation, such as the Solnhofen Limestone beds.
Their rarity may either be a result of poor distribution or their tiny body size and delicate skeleton.
Scientists have had a hard time studying this pterosaur due to their limited fossil record.
It does represent a unique pterosaur group, and studying this flying reptile provides some important scientific insights into the diversity that existed in the world of the pterosaurs and their unique ecological role.
The fact that it looked like an evolutionary hybrid between the two pterosaur suborders is another point of interest for scientists.
Studying the fossil may shed some light on the evolution of the pterosaurs as well as the ancient ecosystems they lived in.
Anurognathus has been featured in various pterosaur/dinosaur-themed documentaries, such as the BBC mini-series “Walking With the Dinosaurs.”
They appeared in two separate episodes of the series titled “Time of the Titans” and “Ballad of Big AI.”
In the Time of the Titans, it was inaccurately depicted as a tiny, bird-like creature that lived almost entirely on the back of sauropod dinosaurs.
The depiction of the Anurognathus in The Ballad of Big Al was slightly more accurate.
Here, it is shown as an independent pterosaur hunting for its own food rather than a symbiont.
Anurognathus and other pterosaurs are also commonly referenced in books, documentaries, and various illustrations.
In places where it is mentioned, emphasis is often placed on its small size, active insectivore diet, and unique adaptations.
Conclusion
Anurognathus was a relatively small flying reptile that lived in Europe during the Late Jurassic Period.
With a body length of about nine centimeters and a wingspan of about 35 centimeters, this rhamphorhynchoid pterosaur was one of the smallest flying reptiles ever found.
It was an insectivore, capable of snatching insects in the air with its wide mouth and sharp teeth during powered flight or while gliding.
Anurognathus showed several unique adaptations, including the lack of a prominent tail.
This is a feature seen in pterodactyloid pterosaurs even though it was a member of the rhamphorhynchoid.
The Anurognathus also had large eyes, which made it capable of hunting in low light conditions.
Due to the small size and delicate skeleton of this pterosaur, very few fossils have been discovered so far, limiting research about this fascinating creature—how it lived and its intricate relationship with other pterosaurs.
FAQs
How did Anurognathus fly?
Anurognathus had membranous wings supported by an elongated fourth finger. It was capable of powered flight, gliding, and maneuvering through the air.
Where have Anurognathus fossils been found?
Fossils of Anurognathus have been discovered in limestone deposits in the Solnhofen Formation of Germany. The first fossil was named and described in 1923.
Is Anurognathus a bat?
No. Although Anurognathus was similar in size to modern bats, it was not a bat. It was a pterosaur, a group of flying reptiles that lived during the Mesozoic Era.
What did Anurognathus eat?
Anurognathus was an insectivorous pterosaur. It primarily feeds on flying insects such as beetles and flies.
Sources:
- https://en.wikipedia.org/wiki/Anurognathus
- https://en.wikipedia.org/wiki/Rhamphorhynchoidea
- https://eartharchives.org/articles/anurognathus-the-tiny-jurassic-pterosaur/index.html
- https://en.wikipedia.org/wiki/Anurognathidae
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