Ctenochasma elegans (von Meyer 1852, C. elegans Wagner 1861) Late Jurassic ~160 mya, skull length ~5 cm was originally considered a species of Pterodactylus, but that was quickly rectified by Wagner (1861). Here Ctenochasma elegans was derived from a sister to No. 40 and phylogenetically preceded Ctenochasma gracile.
There’s a big question as to what is and what isn’t Ctenochasma (see below). The other question refers to the species. Is P. elegans (the holotype described by Wagner 1861) actually Ctenochasma? Or something else? Evidently the specimen was destroyed in World War II and never illustrated or photographed, so this is a problem.
In any case, what specimens we do know are all adult material and if not adults, morphologically identical to adults. This we know from embryos, like Pterodaustro, that had just as long of a rostrum and as small of an orbit as adults. Specimens with a shorter rostrum were phylogenetically more primitive, as demonstrated below. That's how the long rostrum with so many procumbent teeth evolved.
C. roemeri (the holotype genus described by von Meyer 1852, which I haven't yet seen) was based on a partial mandible that had ~54 slender teeth per side of the jaws. C. elegans/gracile is known from more than a dozen specimens with ~100 teeth per side, ranging in skull length from
3.3 cm up to 20 cm long.
Distinct from No. 40, the skull of Ctenochasma elegans was longer and had smaller teeth. The occiput was essentially beneath the expanded cranium.
The cervicals were elongated and more robust. The dorsals and sacrals were smaller and more gracile.
The scapula was larger. The humerus had a more pronounced posterior tuberosity and was overall more gracile. The metacarpus was longer. The fingers were shorter with reduced unguals.
The pelvis was relatively smaller and shallower. The tibia was longer. The foot was smaller with reduced unguals. The central phalanges were more disc-like.
The dorygnathid tree is here. The pterosaur family tree is here. |
