| Campananeyen | |
|---|---|
 | |
| Life restoration | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Superfamily: | †Diplodocoidea |
| Family: | †Rebbachisauridae |
| Genus: | †Campananeyen Lerzo et al.,2024 |
| Species: | †C. fragilissimus |
| Binomial name | |
| †Campananeyen fragilissimus Lerzo et al., 2024 | |
Campananeyen is a genus ofrebbachisauridsauropod dinosaur from the Late Cretaceous (Cenomanian)Candeleros Formation of Argentina. The genus contains asingle species,Campananeyen fragilissimus, known from a fragmentary skeleton.
TheCampananeyenholotype specimen, MMch-PV 71, was discovered in sediments of theCandeleros Formation (Barda Atravesada de Las Campanas locality) nearVilla El Chocón inNeuquén Province, Argentina. The specimen consists of an incomplete skeleton, including thebraincase and the rightquadrate from the skull, a partialdorsal,sacral, andcaudal vertebra, pieces of theilia, and twoungualphalanges.[1] The cranial remains were described in a scientific paper published in 2016, but left unnamed.[2]
In 2024, Lerzo et al.described the specimen as a new genus and species of rebbachisaurid. Thegeneric name,Campananeyen, is derived from Las Campanas—the name of thetype locality—combined with theMapundungunn'eyen', meaning "air", referring to the extreme pneumatic qualities of the holotype. Thespecific name,fragilissimus, means "the most fragile" inLatin, in reference to the notably thin ilium.[1]
Thebraincase ofCampananeyen exhibits several unique characteristics. The crista prootica was poorly developed, and the foramen for cranial nerve VII, thefacial nerve, was open anterior to the crista prootica[1] instead of posterior to it as inLimaysaurus.[2] The paroccipital process waspneumatized. The quadrate fossa, a large fossa on the posterior surface of thequadrate bone, is greatly expanded laterally; all rebbachisaurids have a large quadrate fossa, but that ofCampananenyen is 30—70% larger than any other known rebbachisaurid. The quadrate condyle, which formed the jaw joint, was more similar toNigersaurus thanLimaysaurus in that the medial hemicondyle was twice as wide as the lateral condyle.[1]
Most rebbachisaurids lack thehyposphene-hypantrum articulation between the vertebrae, butCampananeyen is one of the few that has hyposphene-hypantrum articulations. The hyposphene ofCampananeyen is ovoid and hollow posteriorly, as inNigersaurus and an unnamed species from theLa Amarga Formation, and unlike the usual rhomboid hyposphene of most sauropods.[1]
As in other rebbachisaurids, theilium contained pneumatic chambers. Due to the extensive pneumatization, the ilium was thin and fragile, and uniquely toCampananeyen the sacral ribs exhibit a dorsal alar arm that would have reinforced the pelvis to better support the leg muscles, particularly them. iliotibialis.[1]
In their 2024phylogenetic analyses, Lerzo et al. consistently recoveredCampananeyen as thesister taxon ofSidersaura, within theRebbachisauridae, in a clade also containingZapalasaurus. Their results are displayed in thecladogram below. Specimen MACN-Pv-N 35, an unnamed rebbachisaurid from theLa Amarga Formation represented by a single partial vertebra, may also be closely related to these taxa, but it was removed from most analyses to obtain more resolved results.[1]
TheCandeleros Formation is interpreted as adesertdepositional environment, representing the Kokorkom Desert, with someoases in it, andfossils representing a faunal assemblage typical of Middle Cretaceous ecosystems in the western remnants ofGondwana.[3]
The Barda Atravesada de Las Campanas locality from whichCampananeyen was recovered has also yielded partial skeletal remains of another rebbachisaurid,[4] a small unnamedabelisaurid, achelid turtle, andasphenodontian.[5] Several animals are also known from other localities within the formation. The dinosaurs include several more rebbachisaurid sauropods (Limaysaurus,Nopcsaspondylus, andRayososaurus)[6] in addition to titanosaurian sauropods (Andesaurus and an unnamed giant form),[7] diverse theropods (Alnashetri,Bicentenaria,Buitreraptor,Ekrixinatosaurus, andGiganotosaurus),[8] and the enigmatic possiblethyreophoranJakapil.[3] Other animals includerhynchocephalians (Tika andPriosphenodon),[9] the snakeNajash, multiple species of thecrocodyliformAraripesuchus, and the mammalCronopio.[10][11]
{{cite journal}}: CS1 maint: numeric names: authors list (link)
