Cardiodon (meaning "heart tooth", in reference to the shape) was a herbivorous genus of sauropod dinosaur, based on a tooth from the late Bathonian-age Middle Jurassic Forest Marble Formation of Wiltshire, England. Historically, it is very obscure and usually referred to Cetiosaurus, but recent analyses suggest that it is a distinct genus, and possibly related to Turiasaurus. Cardiodon was the first sauropod genus named.
Temporal range: Middle Jurassic
Richard Owen named the genus for a now-lost tooth, part of the collection of naturalist Joseph Chaning Pearce, found near Bradford-on-Avon, but did not assign it a specific name at the time. The generic name is derived from Greek καρδία, kardia, "heart", and ὀδών, odon, "tooth", in reference to its heart-shaped profile. A few years later, in 1844, he added the specific name rugulosus, meaning "wrinkled" in Latin. Cardiodon was the first sauropod given a formal name to, though Owen was at the time completely unaware of the sauropod nature of the find.
Within a few decades, he and others were viewing Cardiodon as a possible synonym of his most well-known sauropod genus, Cetiosaurus. Richard Lydekker formalized this view in a roundabout way in 1890, by assigning Cetiosaurus oxoniensis to Cardiodon on the basis of teeth from Oxfordshire associated with a skeleton of C. oxoniensis. He also added a second tooth (BMNH R1527) from the Great Oolite near Cirencester, Gloucestershire. More typically, Cardiodon has been assigned to Cetiosaurus, sometimes as a separate species Cetiosaurus rugulosus, in spite of its priority.
In 2003, Paul Upchurch and John Martin, reviewing Cetiosaurus, found that there is little evidence to assign the C. oxoniensis teeth to the skeleton, and the "C. oxoniensis" teeth differ from the Cardiodon teeth (Cardiodon teeth are convex facing the tongue); therefore, they supported Cardiodon being retained as its own genus. Upchurch et al. (2004) repeated this assessment, and found that though the teeth have no known autapomorphies, they are those of a eusauropod. More recently, Royo-Torres et al. (2006), in their description of Turiasaurus, pointed out Cardiodon as a possible relative to their new, giant sauropod, placing it in the Turiasauria. Earlier, Cardiodon had been usually assigned to the Cetiosauridae or a Cardiodontidae of its own.
The original tooth shows, as far as can be deduced from the surviving illustrations, the rare combination of being spatulate and having a convex inner side, though the convexity is slight. Its crown is short and wide, slightly curving to the inside. The outer side is strongly convexly curved from the front to the rear. On this side a shallow groove is present, running parallel to the rear edge. The crown tapers towards its tip. The edges have no denticles. The enamel shows the little wrinkles to which the specific name refers.
Apatosaurinae is the name of a subfamily of diplodocid sauropods that existed between 157 and 150 million years ago in North America. The group includes two genera for certain, Apatosaurus and Brontosaurus, with at least five species. Atlantosaurus and Amphicoelias might also belong to this group.Below is a cladogram of apatosaurinae interrelationships based on Tschopp et al., 2015.Argyrosauridae
Argyrosauridae is a family of large titanosaurian dinosaurs known from the late Cretaceous period of Argentina and Egypt. The group has been recovered as monophyletic, including the type genus Argyrosaurus as well as Paralititan.Brasilotitan
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.Cetiosaurus
Cetiosaurus () meaning 'whale lizard', from the Greek keteios/κήτειος meaning 'sea monster' (later, 'whale') and sauros/σαυρος meaning 'lizard', is a herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 167 million years ago in what is now Europe and Africa.
Cetiosaurus was in 1842 the first sauropod from which bones were described and is the most complete sauropod found in England. It was so named because its describer, Sir Richard Owen, supposed it was a marine creature, initially an extremely large crocodile, and did not recognise it for a land-dwelling dinosaur. Because of the early description many species would be named in the genus, eventually eighteen of them. Most of these have now been placed in other genera or are understood to be dubious names, based on poor fossil material. The last is true also of the original type species, Cetiosaurus medius, and so C. oxoniensis was officially made the new type species in 2014. C. oxoniensis is based on three more or less complete specimens, discovered from 1868 onwards. Together they contain most of the bones, with the exception of the skull.
Cetiosaurus oxoniensis was a "primitive", quadrupedal, long-necked, small-headed herbivore. It had a shorter tail and neck than most sauropods. The forelimbs on the other hand, were relatively long. C. oxoniensis is estimated to have been about 16 metres (52 ft) long and to have weighed roughly 11 tonnes (12 short tons).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.Eusauropoda
Eusauropoda (meaning "true sauropods") is a derived clade of sauropod dinosaurs. Eusauropods represent the node-based group that includes all descendant sauropods starting with the basal eusauropods of Shunosaurus, and possibly Barapasaurus, and Amygdalodon, but excluding Vulcanodon and Rhoetosaurus. The Eusauropoda was coined in 1995 by Paul Upchurch to create a monophyletic new taxonomic group that would include all sauropods, except for the vulcanodontids.Eusauropoda are herbivorous, quadrupedal, and have long necks. They have been found in South America, Europe, North America, Asia, Australia, and Africa. The temporal range of Eusauropoda ranges from the early Jurassic to the Latest Cretaceous periods. The most basal forms of eusauropods are not well known and because the cranial material for the Vulcanodon is not available, and the distribution of some of these shared derived traits that distinguish Eusauropoda is still completely clear.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.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.Pilmatueia
Pilmatueia is a diplodocoid sauropod belonging to the family Dicraeosauridae that lived in Argentina during the Early Cretaceous.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.Turiasauria
Turiasauria is an unranked clade of basal sauropod dinosaurs known from Middle Jurassic to Early Cretaceous deposits in Europe, North America, and Africa.Wintonotitan
Wintonotitan (meaning "Winton titan") is a genus of titanosauriform dinosaur from late Albian (Early Cretaceous)-age Winton Formation of Australia. It is known from partial postcranial remains.