Thescelosaurus (Wondrous lizard)
Thescelosaurus (Wondrous lizard)
Named By : Charles W. Gilmore - 1913
Diet : Herbivore
Size : Estimated 2.5 – 4 meters long
Type of Dinosaur : Euornithopod
Type Species : T. neglectus, T. garbanii, T. assiniboiensis
Found in : Canada, Alberta - Dinosaur Park Formation, Oldman Formation, Scollard Formation, Saskatchewan - Frenchman Formation, Ravenscrag Formation. USA, Colorado - Laramie Formation, Montana - Hell Creek Formation, Lance Formation, New Mexico - Fruitland Formation, North Dakota - Hell Creek Formation, South Dakota - Hell Creek Formation, Lance Formation, Wyoming - Lance Formation
When it Lived : Late Cretaceous, 76-67 million years ago
Thescelosaurus (/,thesIl@’so:r@s/ THESS-il-@SOR-@s Thescelosaurus (/,thesIl@’so:r Greek theskelos (theskelostheskelos) that means “godlike”, “marvellous””wondrous” or “wondrous” and sauros (sauros) “lizard”) was an genus belonging to a small neornithischian dinosaurs which appeared in the middle in the Late Cretaceous period in North America. It was a part of dinosaurs’ last species prior to the Cretaceous-Paleogene extinctive event about 65 million years earlier. The quality and preservation of its fossils indicate that it could prefer living close to streams.
The bipedal neornithischian has been identified by a number of skeletons that are partial and skulls which indicate that it was approximately 2.5 or 4.0 metres (8.2 to 13.1 feet) in length, on average. It was strong hindlimbs with small hands that were wide, and a head that had an elongate, pointed snout. The shape of the jaws and teeth suggests a predominantly herbivore species. The genus Dinosaurs is classified as a neornithischian that is traditionally classified as a hypsilophodont but is now recognized in a different way from Hypsilophodon. There are several species that have been proposed for this Genus. Three species are currently recognized as valid: the original species T. neglectus T. garbanii and T. assiniboiensis.
The genus came under media scrutiny in 2000 when the discovery of a specimen at the time of its discovery at South Dakota, United States was believed to contain an emaciated heart. There was plenty of debate about whether the remains could be the heart. There are many scientists who question the authenticity of the object in the context of an confirmation.
The first sample that is part of Thescelosaurus (USNM 757) was first discovered during the year 1891, by paleontologists John Bell Hatcher and William H. Utterback who were working on sediments from the Maastrichtian age of the late. Upper Cretaceous Lance Formation of Niobrara County (at the time part of Converse County), Wyoming, USA. The skeleton was stored in its shipping containers for several years, before Charles W. Gilmore of the Smithsonian Institution’s National Museum of Natural History made it available for study and detailed it in a brief paper in 1913. He named It T. neglectus (neglectus: “neglected”). The time was when he believed it was closely related to Camptosaurus. He wrote a comprehensive monograph in 1915, which described the preserved skeleton. The specimen was mostly in natural articulation and had only the neck and head that were lost to erosion. The name derives from the shock Gilmore was in when he discovered this amazing specimen, which was left untended to for quite a long time. He believed it was an agile and light animal and put it in the Hypsilophodontidae which is a group of tiny bipedal dinosaurs.
Similar remains of animals were found in the late 19th century and into the 20th century. Another well-preserved and preserved skeleton from the somewhat older Horseshoe Canyon Formation, in Alberta, Canada, was called T. warreni in the hands of William Parks in 1926. The skeleton was distinguished that T. neglectus which is why Charles M. Sternberg placed it into a new species, Parksosaurus, in 1937. Sternberg also identified another specie, T. Edmontonensis which was derived from a different articulated skeleton. This time, it was with a skull that was partially uncovered (NMC 8537) and called attention to the genus’s heavy structure and large bones. Because of these distinct features from the typical light hypsilophodont structure, he suggested the genus was worthy of its own family, Thescelosaurinae. T. edmontonensis has, since the review of Peter Galton in 1974 generally been thought to be an extra robust specimen (possibly being the opposite sex of the type species) from T. neglectus. Yet, Boyd and colleagues found that they could not attribute it to one of their species valid to Thescelosaurus. They viewed the specimen as having a questionable place within the Genus. Another issue concerning T. Edmontonensis is the ankle which Galton said was injured and misinterpreted. However, it was considered in the work of William J. Morris (1976) as distinct as T. neglectus.
In his article, Morris described a specimen (SDSM 7210) comprised of a fragmented skull, with a large ridge on the cheek and lower jaw and four vertebrae that are partially displaced along with two bone fragments, as an unknown species of Thescelosaurus that was found in the Maastrichtian-late Maastrichtian age Hell Creek Formation of Harding County, South Dakota, USA. Morris drew attention to the premaxillary teeth as well as its an inset toothline that Morris believed to be indicating the presence of muscles in the cheeks. Morris also highlighted the flaring outwardly of the premaxilla (which could have created a large beak) and the large palpebrals. The skull was identified for hypsilophodonts that were not named several years, but it was not until Galton declared it to be the standard specimen belonging to a new genus as well as the specie Bugenasaura infernalis (“large-cheeked lizard that is found in Lower Regions” infernalis being an allusion to the Hell Creek Formation). Morris also identified a new species of Thescelosaurus for the specimen LACM 33542 as T. garbanii (with a question mark as the specimen was not certain if it was a species). LACM 33542 contained a huge partially hindlimb (“a third larger than the described samples from T. neglectus or Parksosaurus and nearly twice as big than Hypsilophodon”) comprising the foot, tarsus bones in the shin and a portion of thigh bone. There were also five cervical (neck) and 11 dorsal (back) vertebrae, which are from the Hell Creek Formation of Garfield County, Montana, USA. The fossil was found by amateur paleontologist Harley Garbani, hence the designation. T. garbanii would have measured around 4.5 metres (15 feet) in length, which is more than typical examples from T. neglectus. Apart from its dimensions, Morris drew attention to how the ankle was made and he believed it as unique, excluding comparison to Thescelosaurus, which he considered to be an entirely separate species. Since Morris thought that ankles from T. garbanii compared favorably with those that of T. edmontonensis, he decided to assign the species to Thescelosaurus. However, the literature on science supports Galton’s belief that T. Edmontonensis was distinct in any way from T. neglectus (see the previous paragraph). In the same paper in which Galton wrote about Bugenasaura, Galton demonstrated that the traits Morris believed to be the connection between T. garbanii and T. edmontonensis were the result of injuries to the latter’s ankle, which means that T. garbanii could also be thought to be distinct from T. Thescelosaurus. To make it easier to accommodate the type of animal, Galton claimed that the species was part of his new Genus Bugenasaura and was identified as B. garbanii, although Galton also pointed out that it might be related to the similar-sized pachycephalosaurid Stygimoloch or even belong to a third unidentified dinosaur.
Clint Boyd and colleagues published an update of Thescelosaurus, Bugenasaura, and Parksosaurus in 2009, using a new skull material as the basis for. They concluded that Parksosaurus was in fact distinct from Thescelosaurus as well as The skull from Bugenasaura infernalis was basically the same as that found with a postcranial skull which was identical to Thescelosaurus. Since B infernalis was not able to be distinguished from Thescelosaurus and the Genus as a synonym for Thescelosaurus however, they regarded the species as a dubious species as well as SDSM 7210 to be an instance of T. Sp. They discovered that LACM 33542 was fragmentary, but it was actually a specimen of Thescelosaurus. They agree that with Morris in that their ankles were distinct and relegated this specimen back in the category of T. garbanii. They also noted the presence of an additional specimen RSM P.1225.1 was different from T. neglectus by a few specific anatomical characteristics, and could be an entirely new species. Thus, Thescelosaurus per Boyd et al. (2009) is identified by at most two or possibly three valid species: the type specie T. neglectus T. garbanii, and possibly a species that is not named. In December of 2011, RSM P.1225.1 was assigned to its own species, Thescelosaurus assiniboiensis. It was designated in the hands of Caleb M. Brown, Clint A. Boyd and Anthony P. Russell and is only known through its holotype, which is a tiny articulated, almost completely skeleton of the Frenchman Formation (late Maastrichtian stage) of Saskatchewan.