| Carniadactylus | |
|---|---|
 | |
| Holotype | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | †Pterosauria |
| Family: | †Eudimorphodontidae |
| Subfamily: | †Eudimorphodontinae |
| Genus: | †Carniadactylus Dalla Vecchia, 2009 |
| Species: | †C. rosenfeldi |
| Binomial name | |
| †Carniadactylus rosenfeldi (Dalla Vecchia, 1995) | |
| Synonyms | |
| |
Carniadactylus is a genus ofpterosaur which existed inEurope during theLate Triassic period (Norian stage,[1] about 217-213 million years ago).[2] The genus contains a single species,Carniadactylus rosenfeldi.
In 1995 theItalianpaleontologistFabio Marco Dalla Vecchia named a new species of the genusEudimorphodon:E. rosenfeldi. Thespecific name honors the finderCorrado Rosenfeld.[3] Theholotype was MFSN 1797, a partial fossil skeleton with parts of the skull and lower jaws, but lacking the tail, found nearUdine.
It soon became clear however, that incladistic analysesE. rosenfeldi was not the sister taxon of thetype species ofEudimorphodon:E. ranzii. This made, dependent on the precise analysis, the genusparaphyletic orpolyphyletic.
To avoid this Dalla Vecchia in 2009 created the new genusCarniadactylus. The type species isCarniadactylus rosenfeldi. The genus name is derived fromCarnia, the name of the region the fossil was found, and Greekdaktylos, "finger", a reference to the wing finger typical of pterosaurs. A second specimen, MPUM 6009, is theparatype, consisting of an almost complete skeleton that however has been largely preserved as an impression only. It is a third shorter than the holotype, that itself indicated a wingspan of about seventy centimetres. The disparity was by Dalla Vecchia explained as intraspecific variability.[4]
In 1978,Rupert Wild described a small pterosaur specimen in the collection of theMuseo di Paleontologia dell´Università di Milano, found nearCene, Lombardy. He referred to it as the "Milan Exemplar" and identified it as a juvenile ofEudimorphodon ranzii. The specimen, MPUM 6009, was found in a layer of theCalcari di Zorzino Formation dating from the earlyNorian (upperAlaunian).[5] It consists of a partial skeleton including the skull, compressed on a single plate. It is largely articulated and includes the lower jaws, most of the wings, much of the vertebral column except the tail, and hindlimb elements. Some bones have only been preserved as impressions. Wild noted considerable differences with thetype specimen ofEudimorphodon but these were explained as reflecting the young age of the animal.[6]
Fabio Marco Dalla Vecchia andAlexander Kellner concluded the specimen must have been at least subadult in view of the fusion of the scapula and thecoracoid, the upper wristbones being fused into a syncarpal, and the fusion of the extensor process on the first wing phalanx.[4][7] Dalla Vecchia referred the specimen toCarniadactylus rosenfeldi.[4] Kellner later concluded that the Milan Exemplar represented a different species fromCarniadactylus. He argued it showed differences in build that could not be explained by individual variation, it was much smaller though of similar age, and it was of a younger geological age. In 2015, he named it as the separate genus and speciesBergamodactylus wildi. The generic name combines a reference toBergamo with a Greek δάκτυλος,daktylos, "finger", a usual suffix in pterosaur names sincePterodactylus. Thespecific name honours Wild. Kellner placedBergamodactylus, within theNovialoidea, in theCampylognathoidea.[5]
In 2018, Dalla Vecchia argued that Kellner's observations on development in pterosaurs were oversimplified, and that the Milan Exemplar's distinguishing features were ambiguous, invalid, or individual variation at best. As a result, Dalla Vecchia referred the specimen back toCarniadactylus, renderingBergamodactylus wildi a junior synonym ofCarniadactylus rosenfeldi.[8]
Carniadactylus was similar in appearance and anatomy to its close relativeEudimorphodon, though it was significantly smaller. LikeEudimorphodon, it is notable for its complex multi-cusped teeth. Despite their similarities, the size difference between these two pterosaurs likely meant that they occupied different niches and relied on different food sources. This is supported by studies of their teeth. While similar in construction, the teeth ofCarniadactylus show little to no wear, unlike the larger, fish-eatingEudimorphodon, which may have been able to chew its food. The smallerCarniadactylus probably fed on smaller, soft-bodied prey like worms and insect larvae.[9]
According to earlier analyses byAlexander Kellner,Carniadactylus was thought to be related toPeteinosaurus within theDimorphodontidae.David Unwin later placed it into theCampylognathoididae. This was supported by an analysis by Dalla Vecchia that showedCarniadactylus as the sister taxon ofCaviramus. However, a more thorough phylogenetic analysis by Andres & Myers in 2013 supported the original interpretation ofCarniadactylus as the sister taxon to the type species ofEudimorphodon, and they reclassified it within that genus.[10] The following phylogenetic analysis follows the topology of Upchurchet al. (2015).[11]
In 2020 however, a study upheld by Matthew G. Baron about early pterosaur interrelationships foundCarniadactylus to group withCaviramus,Raeticodactylus, and theAustriadraconidae, which in turn were within a clade calledCaviramidae.[12]
