Anurognathus

Discovery and Name Origin: “Jaw Without a Tail”

Well-Preserved Fossils and a Connection to Japan

The fossils of Anurognathus were discovered in the same geological strata as Archaeopteryx.
What is particularly noteworthy is the excellent condition of the discovered fossils.
Despite being an extremely small creature, it was preserved in such pristine condition that there were more than enough features to identify the species.
Interestingly, although the discoverer was a German scholar, he is said to have had deep ties to Japan.

Meaning of the Name

The genus name Anurognathus directly describes its physical characteristics, meaning “jaw without a tail.”
True to its name, its most prominent features were its “short tail” and “unique head,” which were unseen in other pterosaurs of its lineage at the time.

A Taxonomic Paradox: An Advanced Tail and Primitive Wrists

The taxonomic placement of Anurognathus is highly unique, possessing a combination of features that hint at a transitional phase in evolution.

A “Short Tail” Despite Being a Rhamphorhynchoid?

Taxonomically, they are classified under the “rhamphorhynchoids.”
This group, which also includes Dimorphodon—familiar from the Jurassic Park film series—is typically characterized by having a “long tail” with a “diamond-shaped vane” at the end.

However, despite belonging to this group, the tail of Anurognathus is exceptionally short.
The characteristics of its tail resembled the tailbones seen in modern birds or the advanced pterosaurs (pterodactyloids) that appeared much later, such as Pteranodon.

Wrists Remained “Primitive”

At first glance, it looks like an advanced pterosaur, but it had not entirely evolved past its roots.
Their bodies still firmly retained features typical of early pterosaurs like the rhamphorhynchoids, such as short carpal (wrist) bones.
In other words, as a representative pterosaur of the family Anurognathidae, Anurognathus was a peculiar creature where primitive and seemingly advanced features coexisted.

Bat-Like Appearance and Physical Characteristics

Anurognathus was a very small pterosaur.
It is said that its appearance was akin to that of a modern bat.

Size

Its body length was a mere 9 centimeters (3.5 inches), with a wingspan of about 0.5 meters (1.6 feet).

Head

Its skull was tall and short from front to back.
The snout was rounded.

Teeth

Inside its mouth, small, sharply pointed teeth grew straight up, structured to ensure prey could not escape.

Wings

Compared to its body length, its wings were elongated and well-developed, giving it excellent gliding capabilities.

Ecology as an Aerial Hunter

Preying on Insects Like a Nightjar

Given these physical characteristics, Anurognathus is believed to have been insectivorous.
Their hunting style is often compared to that of the modern bird, the “nightjar.”
Utilizing their excellent flight capabilities and agility, they swiftly flew through the air, snatching up flying insects one after another.

“Agility” Over Speed

While their flight capabilities may not have allowed for high maximum speeds, they seem to have been specialized for “agility.”
In addition to the gliding ability provided by their elongated wings, their short-tailed bodies allowed for tight turns in the air.
This ability would have been immensely helpful when hunting evasive insects like butterflies mid-air.

In the skies of Jurassic Germany, Anurognathus—with its adorable tiny body and peculiar “tailless” appearance—played a vital role in the ecosystem.