Iani

Genus of iguanodontian dinosaurs

Iani
Temporal range: Late Cretaceous (Cenomanian), ~99.5 Ma
PreꞒ
O
S
D
C
P
T
J
K
Pg
N
Skeletal reconstruction showing known fossil material in green
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Ornithischia
Clade: Ornithopoda
Clade: Rhabdodontomorpha
Genus: Iani
Zanno et al., 2023
Species:
I. smithi
Binomial name
Iani smithi
Zanno et al., 2023

Iani (after Ianus) is an extinct genus of rhabdodontomorph iguanodontian dinosaur from the Late Cretaceous Cedar Mountain Formation of Utah, United States. The genus contains a single species, I. smithi, known from a partial skeleton including the skull. Its discovery serves as a link between the genus Tenontosaurus and the Rhabdodontidae, with both along with Iani being members of the clade Rhabdodontomorpha.[1]

Discovery and naming

The Iani holotype specimen, NCSM 29373, was discovered in 2014 in sediments of the Cedar Mountain Formation (lower Mussentuchit Member) in Emery County, Utah, United States. The specimen consists of a partial skeleton including a nearly complete, disarticulated skull, cervical, dorsal, sacral, and caudal vertebrae, ribs and haemal arches, partial pectoral and pelvic girdles, and the right arm and leg.[1]

In 2023, Zanno et al. described Iani smithi as a new genus and species of rhabdodontomorph iguanodontian based on these fossil remains. The generic name, "Iani", alludes to Ianus, the Roman god of transitions, referencing the changing biota of the time. The specific name, "smithi", honors Joshua Aaron Smith and his paleontological contributions.[1]

Classification

Zanno et al. (2023) recovered Iani as a basal rhabdodontomorph member of the Iguanodontia. They interpreted it as a transitional taxon between Tenontosaurus and other Late Cretaceous rhabdodontomorphs (the Rhabdodontidae). The cladograms below display the results of their phylogenetic analyses using different datasets:[1]

Topology 1: Poole (2022) dataset[2]


Topology 2: Dieudonné et al. (2021) dataset[3]

Rhabdodontomorpha

Tenontosaurus dossi

Tenontosaurus tilletti

Iani

Rhabdodon sp1

Rhabdodon priscus

Zalmoxes shqiperorum

Zalmoxes robustus

Mochlodon vorosi

Mochlodon suessi

References

  1. ^ a b c d Zanno, Lindsay E.; Gates, Terry A.; Ayrahami, Haviv M.; Tucker, Ryan T.; Makovicky, Peter J. (2023). "An early-diverging iguanodontian (Dinosauria: Rhabdodontomorpha) from the Late Cretaceous of North America". PLOS ONE. 18 (6). e0286042. doi:10.1371/journal.pone.0286042. PMC 10246810. PMID 37285376.
  2. ^ Poole K. 2022. "Phylogeny of iguanodontian dinosaurs and the evolution of quadrupedality". Palaeontologia Electronica. 25(3):1–65
  3. ^ Dieudonné P.E., Cruzado-Caballero P., Godefroit P. & Tortosa T. 2021. "A new phylogeny of cerapodan dinosaurs". Historical Biology. 33(10): 2335
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Taxon identifiers
Iani