| Rhabdodon | |
|---|---|
 | |
| ReconstructedR. priscus skeleton | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Ornithopoda |
| Family: | †Rhabdodontidae |
| Genus: | †Rhabdodon Matheron,1869 |
| Species | |
Rhabdodon (meaning "fluted tooth") is agenus ofornithopoddinosaur that lived inEurope approximately 70-66 million years ago in the LateCretaceous. It is similar in build to a very robust "hypsilophodont" (non-iguanodont ornithopod), though all modern phylogenetic analyses find this to be an unnatural grouping, andRhabdodon to be a basal member ofIguanodontia. It was large amongst its relatives, measuring 4 m (13 ft) long and weighing 250 kg (550 lb), with some specimens possibly reaching up to 6 m (20 ft) long.[1]
Two species ofRhabdodon are known,Rhabdodon priscus, the type species, andR. septimanicus (Buffetaut and Le Loeuff, 1991).Rhabdodon remains are currently known from southernFrance, although fragmentary remains from eastern Spain have been assigned to the genus.[2]Rhabdodon was large compared to its nearest relatives, and indeed one recent paper ( Ősiet al. (2012)) determined it is larger than the basal rhabdodontid status; from this they suggested that it actually experienced gigantism on the "mainland"; and not insular dwarfism as previous suggested.[3]
Rhabdodon was probably an important herbivore in Cretaceous Europe.[citation needed]Rhabdodon's predators include the abelisauridArcovenator, and young may have been prey forPyroraptor.[citation needed] Isotope analysis shows thatRhabdodon, along with its smaller cousinZalmoxes, ateC3 plants.[4][5]
Rhabdodon priscus is known from a specimen from theMarnes Rouges Inférieures Formation. The material ofRhabdodon priscus includes a dentary and many other postcranial remains. More specifically, it is known from the Bellevue layer, which has produced many vertebrate fossils. Even though it produced many vertebrates, the formation only has a scarce record of plants and invertebrates. The non-dinosaurian vertebrates consist ofLepisosteus, an indeterminate turtle, and a crocodile. Dinosaurian fauna from the Marnes Rouges Inférieures Formation includeAmpelosaurus, an animal classified as Dromaeosauridae indet., and an indeterminate ankylosaur.[6][7] The birdGargantuavis philoinos, and dinosaur eggs have also been recovered.[7]
Another formationRhabdodon priscus is known from isGres de Saint-Chinian. Along with bothRhabdodon priscus,Rhabdodon septimanicus, dinosaur eggs,Nodosauridae indet. (previously known asRhodanosaurus lugdunensis), Theropoda indet.,Variraptor mechinorum,Avialae indet.,Enantiornithes indet., and a possibleAbelisauridae indet. are known from this formation.[7]
Rhabdodon priscus is one of few vertebrates known from theGres de Labarre Formation. The only other fossils from the formation belong toAmpelosaurus atacis and a Nodosauridae indet.[7]
Rhabdodon sp. is from the latest Cretaceous aged Lo Hueco region in theVillalba de la Sierra Formation. A study shows that the area around Lo Hueco dates to the lateCampanian and earlyMaastrichtian, although a more recent study revised the later date to the latest Maastrichtian.[8] The study showed that Lo Hueco was near the coast of theTethys Sea,[8] a large seaway through southern Europe and northern Africa. The area directly on the coast was shown to be a brackish-freshwater aquatic environment, with a muddy flood-plain beside it. Lo Hueco was found to be inside the flood-plain. The flood plain was found to have distributary channels of sand and terrigenous material.[9]
Many dinosaurs have been found in the Villalba de la Sierra Formation, includingRhabdodon sp. They consist of possibleLirainosaurus remains,Ampelosaurus atacis, unknown basal euornithopods, probable ankylosaurians, one undetermined dromaeosaurine, and one unknown velociraptorine. The plants known from the formation are represented by carbonized branches and leaves. Invertebrates are solely known frombivalves andgastropods. Fishes from the formation includelepisosteids, and unidentifiedactinopterygians andteleosteans. Turtle fossils are very common, but only two different groups have been identified, thebothremydidsPolysternon andRosasia, along with an undeterminedPancryptodiran.Squamate lizards are known only from a few undetermined specimens, andeusuchian crocodiles are known from a specimen with similarities toAllodaposuchus andMusturzabalsuchus.[9]
The cladogram below is based on the analysis of Ösiet al. (2012):[3]
