| Seazzadactylus | |
|---|---|
 | |
| Holotype specimen | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | †Pterosauromorpha |
| Order: | †Pterosauria |
| Clade: | †Caviramidae |
| Family: | †Austriadraconidae |
| Genus: | †Seazzadactylus Dalla Vecchia, 2019 |
| Type species | |
| †Seazzadactylus venieri Dalla Vecchia, 2019 | |
Seazzadactylus is a basalpterosaur genus that lived during the lateTriassic (Norian stage, about 219-214 million years ago)[1] in the area of present-dayItaly.
In 1997, amateur paleontologist Umberto Venier discovered the skeleton of a pterosaur in a boulder laying in the bed of the Seazza brook, just before it joins theTagliamento river, nearPreone in theDolomites. Venier brought the find to theMuseo Friulano di Storia Naturale atUdine. After partial preparation paleontologistFabio Marco Dalla Vecchia announced the discovery in the scientific literature in 2000.[2] In 2003, Dalla Vecchia referred the specimen toEudimorphodon.[3] In 2009 however, further preparation made him conclude that it was a species new to science, not identical to eitherEudimorphodon orCarniadactylus.[4]
In 2019, Dalla Vecchia named and described thetype speciesSeazzadactylus venieri. The generic name combines that of the Seazza with the Greekdaktylos, 'finger'. Thespecific name honours Venier as discoverer.
Theholotype,MFSN 21545, was found in a layer of theDolomia di Forni Formation dating from the middle to upperNorian. It consists of a partial skeleton with skull and lower jaws. The skeleton is not articulated but the bones are in close association. It lacks the tail and most feet bones. It represents a subadult individual, not fully grown.[5]
Dalla Vecchia established a number ofapomorphic traits. In thepraemaxilla the teeth are limited to the front half of the body. Thejugal bone has a high front branch, tapering to the front and below into a sharp needle-like point. The main body of the jugal bone is pierced in the middle by a large foramen. The front branch of thepterygoid bone makes a right angle to the outer side. The ectopterygoid bone is positioned behind the pterygoid and has a recurved outer side branch in the direction of the jugal as well as a rear branch. Teeth in themaxilla and thedentary bone possess multiple cusps, sometimes as high as six or seven, while erupted teeth with three cusps are absent. The first, second and third maxillary teeth are recurved, with the curvature gradually diminishing along the series. The shoulder blade is fan-like expanded to the rear. The pteroid bone is small and slender, formed like anexclamation mark.[5]
Seazzadactylus was placed in the Pterosauria in 2019, in a basal position outside of theMonofenestrata. Acladistic analysis showed it was part of a yet-unnamedclade also containingArcticodactylus,Austriadraco,Carniadactylus,Raeticodactylus andCaviramus.[5] This unnamed clade was eventually named asCaviramidae in a 2020 study by Matthew G. Baron.[6] In the evolutionary treeSeazzadactylus would be positioned directly aboveAustriadraco and belowCarniadactylus.Eudimorphodon was not recovered as a close relative but in a more derived position instead, underCampylognathoides.[5]
