Anurognathus (Dmitri Bogdanov).


Anurognathus (Greek for "without tail and jaw"); pronounced ANN-your-OG-nah-thuss


Woodlands of western Europe

Historical Epoch:

Late Jurassic (150 million years ago)

Size and Weight:

About three inches long and a few ounces



Distinguishing Characteristics:

Small size; stubby tail; short head with pin-shaped teeth; 20-inch wingspan


About Anurognathus

Except for the fact that it was technically a pterosaur, Anurognathus would qualify as the smallest dinosaur that ever lived.

This hummingbird-sized reptile, no more than three inches long and a handful of ounces, differed from its fellow pterosaurs of the late Jurassic period thanks to its stubby tail and short (yet extremely strong) jaws, after which its name, Greek for "without tail and jaw," derives. The wings of Anurognathus were very thin and delicate, stretching from the fourth fingers of its front talons back to its ankles, and they may have been brightly colored, like those of modern butterflies. This pterosaur is known by a single, well-preserved fossil specimen discovered in Germany's famous Solnhofen beds, also the source of the contemporary "dino-bird" Archaeopteryx; a second, smaller specimen has been identified, but has yet to be described in the published literature.

The exact classification of Anurognathus has been a subject of debate; this pterosaur doesn't fit easily into either the rhamphorhynchoid or pterodactyloid family trees (typified, respectively, by the small, long-tailed, big-headed Rhamphorhynchus and the slightly larger, stubby-tailed, slender-headed Pterodactylus).

Lately, the weight of opinion is that Anurognathus and its relatives (including the similarly tiny Jeholopterus and Batrachognathus) constituted a relatively unevolved "sister taxon" to the pterodactyloids. (Despite its primitive appearance, it's important to keep in mind that Anurognathus was far from the earliest pterosaur; for example, the slightly bigger Eudimorphodon preceded it by 60 million years!)

Because a free-flying, bite-sized Anurognathus would have made a quick snack for the much bigger pterosaurs of its late Jurassic ecosystem, some paleontologists wonder if this diminutive creature nested on the backs of large sauropods like the contemporary Cetiosaurus and Brachiosaurus, similar to the relationship between the modern Oxpecker bird and the African hippopotamus This arrangement would have afforded Anurognathus some much-needed protection from predators, and the bugs that constantly hovered around skyscraper-sized dinosaurs would have provided it with a steady source of food. Unfortunately, we don't have a scrap of evidence that this symbiotic relationship existed, despite that episode of Walking with Dinosaurs in which a tiny Anurognathus pecks insects off the back of a docile Diplodocus.

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Your Citation
Strauss, Bob. "Anurognathus." ThoughtCo, Jan. 24, 2017, Strauss, Bob. (2017, January 24). Anurognathus. Retrieved from Strauss, Bob. "Anurognathus." ThoughtCo. (accessed March 21, 2018).