Eudimorphodon
Eudimorphodon is a genus of early pterosaurs (Pterosauria) from the Upper Triassic period (Norian to Rhaetian) and thus one of the oldest pterosaurs discovered to date. Its fossil remains were found in 1973 by Mario Pandolfi in limestone formations at the foot of the Alps near Cene in the province of Bergamo.
Like all older pterosaurs, Eudimorphodon has a long tail as a primitive feature. In addition, its metacarpal bone is still relatively short.
The wingspan is one meter. At the end of its long bony tail it possessed a diamond-shaped flap of skin, which probably helped this flying lizard to manoeuvre in the air. Its jaw, only six inches long, is set with 114 distinctly heterodont teeth, some large, single-pointed fangs in the anterior mouth and middle of the upper jaw, and many small, three-pointed and multi-pointed teeth in the middle and posterior regions of the upper and lower jaws. It is thought to have fed on small, primitive bony fish protected with thick ganoid scales. Since this tooth pattern does not appear in any later pterosaurs, Eudimorphodon cannot be their ancestor, but must belong to a lateral lineage extinct at the end of the Triassic.
In 1989, William Amaral discovered a rich fossil site on McKnight Bjerg in eastern Greenland. It was excavated in 1991 and 1992. Part of the material was a small skeleton of a pterosaur. In 2001, Farish Jenkins, Neil Shubin, Stephen Gatesy and Kevin Padian named and described it as a new species of Eudimorphodon: Eudimorphodon cromptonellus. The specific name honors Professor Alfred Walter Crompton. The Latin suffix ~ ellus, indicating diminutive, alluded to the small size of the specimen. The reference to Eudimorphodon was based largely on the similarity of tooth shape, particularly the characteristic multi-cuspid structure with three, four or five points on the crown. In 2003, Alexander Kellner pointed out that other basal pterosaurs also had such teeth. In 2014, Fabio Marco Dalla Vecchia noted that E. cromptonellus had no single feature in common with Eudimorphodon ranzii that was not present in other pterosaurs, but had no distinguishable fang-like teeth, pterygoid teeth, and striated enamel. In 2015, Kellner named a separate genus Arcticodactylus. The genus name derives from Arctic, and Greek δάκτυλος, daktylos, "finger", a common suffix in pterodactyl names since Pterodactylus.
Types
- Eudimorphodon ranzii
- Eudimorphodon rosenfeldi
- Eudimorphodon cromptonellus (until 2014)
Questions and Answers
Q: What type of creature is Eudimorphodon?
A: Eudimorphodon is a recently discovered pterosaur, and comes from shale laid down Upper Triassic rocks in Italy.
Q: How was the skeleton of Eudimorphodon found?
A: A nearly complete skeleton was found in 1973.
Q: What makes the teeth of Eudimorphodon unique?
A: The teeth at the front are fangs, further back the teeth are small and multipointed, many with five cusps. This is unique among pterosaurs, whose teeth are usually of a simple conical form.
Q: What did Eudimorphodon eat?
A: Stomach contents showed it had eaten a small fish, Parapholidophorus. Wear along the sides of these teeth suggests that Eudimorphodon also fed on hard-shelled invertebrates. Juvenile Eudimorphodon had somewhat different and fewer teeth, and may have eaten insects.
Q: How did the top and bottom teeth interact when the jaws were closed?
A: The top and bottom teeth of Eudimorphodon came into direct contact with each other when the jaws were closed, especially at the back of the jaw.
Q: What is unusual about its tail structure compared to other long-tailed pterosaurs?
A: An unsolved puzzle is the flexibility of its tail which lacks very long stiffening vertebral extensions that other long-tailed pterosaurs have.
Q: How does this flexibility affect flight control for this species?
A:This flexibility adds stability to their flight but requires more control by brain for manoeuvring without this stability .
