Eudimorphodon

Name Origin: “True Two Types of Teeth”

The scientific name Eudimorphodon comes from the Greek words for “true (Eu),” “two forms (dimorph),” and “tooth (odon).”
This name derives from the characteristics of the 110 teeth lining its mouth.

Two Types of Teeth with Different Roles

A total of 110 teeth were tightly lined up in its mouth, which measured about 6 cm in length.

A total of 110 teeth were tightly lined up in its mouth

Tip

“Long, pointed fangs” for catching slippery prey.

Back

“Flat teeth” with multiple cusps (serrations).

Because it possessed teeth with clearly different shapes depending on their location, it was crowned with the name “True (heterodont).”

Difference from Dimorphodon

The Jurassic pterosaur “Dimorphodon,” which has a similar name, also possessed two types of teeth, but the shapes of the teeth themselves were basically the same.
A major characteristic of Eudimorphodon is that the roles and shapes were clearly distinct, like fangs and molars. Despite the similarity in names and habitat (Europe), the two are not particularly closely related.

Fish or Crustaceans? Diet Revealed by Worn Teeth

What did they eat using these complex teeth?

Piscivore Theory (Dominant)

The most dominant theory is that they were piscivores (fish-eaters).
Since fish scales have been found in the stomach area and fish fossils have been discovered in the same geological strata, it is believed they caught fish near the surface using their long snouts and sharp front teeth.

Crushing Hard Prey

On the other hand, “wear” was observed on many of the discovered teeth.
Since the biting surfaces were flattened, it is possible they used their back teeth to crush not only fish scales but also prey with hard shells, such as crustaceans.

Earlier than Archaeopteryx! Complete Flight Capabilities

Eudimorphodon lived approximately 210 million years ago.
Although this is long before Archaeopteryx, which is considered the oldest bird, its flight functions were already complete.

Abnormally Long “Fourth Finger” Wings

The “fourth finger (ring finger)” of the forelimb extended abnormally long, forming a wing with a membrane stretched from it.

The fourth finger of the forelimb extended long, forming a wing with a membrane stretched from it.

The wingspan was about 1 meter.
The remaining three fingers had claws, which they could use to climb cliffs or grasp objects.

Long Tail Acting as a Rudder

They had a tail longer than their body, with a diamond-shaped rudder (flap) at the tip.

It had a tail longer than its body, with a diamond-shaped rudder at the tip.

As early pterosaurs, it is believed they used this tail to balance and turn quickly in the air.

Fur and Endothermy

Fossils reveal that they were covered in “fur-like skin,” suggesting they were “endothermic (warm-blooded)” animals capable of maintaining their body temperature.
It was because they had warm blood and a coat that high-energy flight was possible.

Suddenly Appeared in Complete Form: An Evolutionary Mystery

Eudimorphodon appears suddenly in the fossil record during the Late Triassic.
Normally, there should be intermediate stages gradually acquiring wings from “flightless ancestors,” but they are found in a state where “wings and flight capabilities are almost complete.”
Partly because bones are fragile and do not preserve well, definitive ancestral fossils have not been discovered.
They are a precious existence that conveys the “first successful form” of vertebrates advancing into the sky.