re: BSP 1994, the new Eudimorphodon

[David Peters <davidrpeters@earthlink.net>]

Regarding the new Eudimorphodon, BSP 1994:

The specimen, when put together, bears quite a bit of resemblance to the
basalmost Dorygnathus specimens, except for the teeth, of course.
Wellnhofer included Dorygnathus in his chart, but not much in the
discussion. I'm not familiar with the Dory. specimen he chose for the
chart, but Dorygnathus comes in a wide variety. Perhaps the Donau
specimen would have given a closer benchmark.

BSP 1994 and Dorygnathus (Donau) share these similar characters:

1. The slender humerus
2. The small triangular sternal complex
3. The vertical orientation of the slender pubis.
4. The length and shape of the prepubis
5. The dimension of manual 4.1 and 4.2, the first two wing phalanges
would be slightly longer than the elbow when folded.
6. The jugal is also similar, though not exceedinly so.

The broad coracoid is strange. It is the only coracoid that is more than
half as long as its sternal complex along their mutual articulating
edges. It resembles nothing I know of.

Wellnhofer remarked throughout the paper about the relationships between
E. rosenfeldi, MCSNB 8950, E. ranzii and the Bergamo specimen. My work
suggests that multi-cusped teeth represent a primitive grade of
pterosaur, not a genus. After all, Longisquama has multi-cusped teeth,
as do small Tanystropheids. My cladistic analysis places E. rosenfelidi
with the basal anurognathids, MCSNB with Dimorphodon macronyx, the
Bergamo specimen as the basalmost pterosaur and E. ranzii basal to all
but the dimorphodontid pterosaurs.

In my opinion, BSP 1994 is a Eudimorphodon-grade pterosaur, but it is
basal to Dorygnathus, not far from the Donau specimen. Comments are
welcome..

David Peters
St. Louis