Ultrasaurus is a genus of sauropod dinosaur discovered by Haang Mook Kim in South Korea. However, the name was first used unofficially (as a nomen nudum) in 1979 by Jim Jensen to describe a set of giant dinosaur bones he discovered in the United States. Because Kim published the name for his specimen before Jensen could do so officially, Jensen renamed his specimen Ultrasauros. Jensen's giant sauropod was later found to be a chimera, and the type remains are now assigned to Supersaurus.
A collection of bones discovered by Jim Jensen, of Brigham Young University, at the Dry Mesa Quarry, Colorado were originally believed to belong to the largest dinosaur ever. Jensen informally called this supposedly new dinosaur "Ultrasaurus", and this name was widely used by the press and in scientific literature as a nomen nudum (informal name lacking an actual scientific description).
In 1983, Kim Hang-mook published a paper describing a different specimen representing a new dinosaur species, which he named Ultrasaurus tabriensis, because he believed it was an equally giant relative of Jensen's dinosaur. However, Kim's assessment was incorrect. His dinosaur was much smaller than he believed, because he mistook a partial humerus for an ulna. However, since Kim was the first to publish the name Ultrasaurus, the name officially applied to the small South Korean sauropod, and could no longer be used as an official name for Jensen's giant specimen.
Jensen published a paper describing his original discovery in 1985, but since the name Ultrasaurus was already in use (or "preoccupied"), his discovery was renamed in 1991 to Ultrasauros. However, Jensen also made a mistake. His discovery was a chimera; the collection of fossils came from two different dinosaur species, both of which already had names. So his new name, Ultrasauros, is now just an alternate name (junior synonym) for the dinosaur officially known as Supersaurus.
Kim's Ultrasaurus is currently a nomen dubium. Not enough is known about the specimen to formally assign it to a specific family of sauropods. It may even be a member of a known genus or species, which would make the name Ultrasaurus a junior synonym as well.
Brasilotitan is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous (early Maastrichtian) Adamantina Formation of Brazil. The type species is Brasilotitan nemophagus.Cetiosauridae
Cetiosauridae is a family of sauropod dinosaurs. While traditionally a wastebasket taxon containing various unrelated species, some recent studies have found that it may represent a natural clade. Additionally, at least one study has suggested that the mamenchisaurids may represent a sub-group of the cetiosaurids, which would be termed Mamenchisaurinae.Diplodocinae
Diplodocinae is an extinct subfamily of diplodocid sauropods that existed from the Late Jurassic to Early Cretaceous of North America, Europe and South America, about 161.2 to 136.4 million years ago. Genera within the subfamily include Tornieria, Supersaurus, Leinkupal, Galeamopus, Diplodocus, Kaatedocus and Barosaurus.Cladogram of the Diplodocidae after Tschopp, Mateus, and Benson (2015).Eomamenchisaurus
Eomamenchisaurus (meaning "dawn Mamenchisaurus") is a genus of mamenchisaurid sauropod dinosaur from the Middle Jurassic of Yuanmou, Yunnan, China. The type species is E. yuanmouensis, described by Lü Junchang et al. in 2008.Ferganasaurus
Ferganasaurus was a genus of dinosaur first formally described in 2003 by Alifanov and Averianov. The type species is Ferganasaurus verzilini. It was a sauropod similar to Rhoetosaurus. The fossils were discovered in 1966 in Kyrgyzstan from the Balabansai Formation and date to the Callovian stage of the Middle Jurassic.Flagellicaudata
Flagellicaudata is a clade of Dinosauria. It belongs to Sauropoda and includes two families, the Dicraeosauridae and the Diplodocidae.Gravisauria
Gravisauria is a clade of sauropod dinosaurs consisting of some genera, Vulcanodontidae and Eusauropoda.Huangshanlong
Huangshanlong is a genus of mamenchisaurid dinosaurs native to the Anhui province of China. It contains a single species, Huangshanlong anhuiensis. H. anhuiensis represents, along with Anhuilong and Wannanosaurus, one of three dinosaurs fround in Anhui province.Jiutaisaurus
Jiutaisaurus is a genus of sauropod dinosaur from the Quantou Formation of China. Jiutaisaurus was a sauropod which lived during the Cretaceous. The type species, Jiutaisaurus xidiensis, was described by Wu et al. in 2006, and is based on eighteen vertebrae.Kaijutitan
Kaijutitan (meaning "Kaiju titan" after the type of Japanese movie monsters) is a genus of basal titanosaur dinosaur from the Sierra Barrosa Formation from Neuquén Province in Argentina. The type and only species is Kaijutitan maui.Microcoelus
Microcoelus is a dubius genus of small Titanosaurian sauropod dinosaur native to Argentina. It is known from only a single dorsal vertebra. A left humerus was formerly referred to this species, but it is now considered to belong to Neuquensaurus. This species may be a synonym of the contemporary sauropod Neuquensaurus australis.It was described by British paleontologist Richard Lydekker in 1893.Pilmatueia
Pilmatueia is a diplodocoid sauropod belonging to the family Dicraeosauridae that lived in Argentina during the Early Cretaceous.Supersaurus
Supersaurus (meaning "super lizard") is a genus of diplodocid sauropod dinosaur that lived in North America during the Late Jurassic period. The type species, S. vivianae, was first discovered by Vivian Jones of Delta, Colorado, in the middle Morrison Formation of Colorado in 1972. The fossil remains came from the Brushy Basin Member of the formation, dating to about 153 million years ago. A potential second species, S. lourinhanensis, is known from Portugal and has been dated to a similar time.Tambatitanis
Tambatitanis is an extinct genus of titanosauriform dinosaur from the Early Cretaceous (probably early Albian) of Japan. It is known from a single type species, Tambatitanis amicitiae. It was probably around 14 meters long and its mass was estimated at some 4 tonnes. It was a basal titanosauriform and possibly belonged to the Euhelopodidae.Tastavinsaurus
Tastavinsaurus is a genus of sauropod dinosaur belonging to the Titanosauriformes. It is based on a partial skeleton from the Early Cretaceous of Spain. The type species is Tastavinsaurus sanzi, named in honor of the Rio Tastavins in Spain and Spanish paleontologist José Luis Sanz.Tengrisaurus
Tengrisaurus (meaning "Tengri lizard") is a genus of lithostrotian sauropod, from the Early Cretaceous (Barremian-Aptian), of the Murtoi Formation, Russia. It was described in 2017 by Averianov & Skutschas. The type species is T. starkovi.Vulcanodontidae
The Early Jurassic sauropod dinosaurs Zizhongosaurus, Barapasaurus, Tazoudasaurus, and Vulcanodon may form a natural group of basal sauropods called the Vulcanodontidae. Basal vulcanodonts include some of the earliest known examples of sauropods. The family-level name Vulcanodontidae was erected by M.R. Cooper in 1984. In 1995 Hunt et al. published the opinion that the family is synonymous with the Barapasauridae. One of the key morphological features specific to the family is an unusually narrow sacrum.