| Ischioceratops | |
|---|---|
 | |
| Holotype | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | †Ornithischia |
| Clade: | †Ceratopsia |
| Family: | †Leptoceratopsidae |
| Genus: | †Ischioceratops |
| Species: | †I. zhuchengensis |
| Binomial name | |
| †Ischioceratops zhuchengensis Heet al.,2015 | |
Ischioceratops (lit. 'ischium-horned face') is anextinctgenus of small herbivorousceratopsiandinosaur that lived approximately 77.3-73.5million years ago during the latter part of theCretaceousPeriod in what is nowChina.
Ischioceratops was a small sized, moderately-built, ground-dwelling,quadrupedalherbivore, whose total body length has been estimated to be about 2 m (6.6 ft). The ceratopsians were a group of dinosaurs withparrot-like beaks which fed on vegetation and thrived inNorth America andAsia during the Cretaceous Period, which ended approximately 66 million years ago, at which point they all became extinct. Its name means "ischium horned face", referring to the peculiar shape of theischiatic bones.[2]
Ischioceratops existed in theWangshi Group during the late Cretaceous. It lived alongside centrosaurines, saurolophines, and tyrannosaurines. The most common creatures in the formation wereSinoceratops andZhuchengtyrannus.
In 2015, thetype speciesIschioceratops zhuchengensis was named and described by He Yiming, Peter J. Makovicky, Wang Kebai, Chen Shuqing, Corwin Sullivan, Han Fenglu andXu Xing. The generic name combines a reference to theos ischii, its uniquely formedischium, with ~ceratops, "horn face", a usual suffix in the names of Ceratopia. The suffix itself is derived from Greekkeras, "horn", andops, "face". Thespecific name refers to the provenance from Zhucheng. Because the name was published in anelectronic publication,PLoS ONE,Life Science Identifiers were required for its validity. These were 19A423ED-8EAA -4842-9ECF-695876EC5EC0 for the genus and 71CD0FAE-070C-4CC4-96CC-B37D5B1071CE for the species.[2]Ischioceratops was one of eighteen dinosaur taxa from 2015 to be described in open access or free-to-read journals.[3]
TheholotypeZCDM V0O016 was discovered in Kugou, a locality in theShandong Province of China which presents layers of theUpper Cretaceous Wangshi Group, possibly dating from the lateCampanian or earliestMaastrichtian. It is part of theZhucheng Dinosaur Museum collection and it represents an incomplete, partially articulated specimen comprising the entiresacrum, a few ossified tendons, both halves of thepelvis, the anteriormost fifteen caudalvertebrae in an articulated series, and the rightfemur,tibia andfibula.[2]
Ischioceratops was a relatively small ceratopsian, reaching 2 m (6.6 ft) in length. The describing authors indicated some distinguishing traits. The taxon has been referred toLeptoceratopsidae and is distinguished from other known leptoceratopsids based on the following combination of characters: nine sacral vertebrae, more than in any other known basal (non-ceratopsid) ceratopsian but fewer than in ceratopsids; the ischium has a robust shaft that resembles that of a recurved bow and flares gradually to form a subrectangular-shaped obturator process in its middle portion while an elliptical fenestra perforates the obturator process. This morphology, unique for the Dinosauria as a whole, was seen as a singleautapomorphy, unique derived character.[2]
Ischioceratops is one of the few ceratopsian dinosaurs which is not known by the skull. The most peculiar traits are located in the ischium. With most relatives the ischium shaft has a constant curvature to the rear. Another characteristic ofIschioceratops is the presence of an elevation in the proximal part of its tail, which is present also inProtoceratops,Koreaceratops and in a more similar way inMontanoceratops andCerasinops. The elevation forms a tail crest.
Phylogenetic analyzes confirmedIschioceratops as a leptoceratopsid. Its closest relative taxon orsister species wasMontanoceratops.The followingcladogram is based on an analysis in the describing paper of 2015.[2]
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