The Forest Sandstone is a geological formation in southern Africa , dating to roughly between 200 and 190 million years ago and covering the Hettangian to Sinemurian stages of the Jurassic Period in the Mesozoic Era . As its name suggests, it consists mainly of sandstone .
10-668: Fossils of the prosauropod dinosaur Massospondylus and the primitive sauropod Vulcanodon have been recovered from the Forest Sandstone. The formation is a sedimentary unit, consisting mainly of aeolian sands and silts with interbedded fluvial sediments, laid down during a period of increasing aridity. The Forest Sandstone is found in Botswana , Zambia and Zimbabwe , in the Mid-Zambezi, Mana Pools, Cabora Bassa and Limpopo Basins , with its greatest thickness in
20-577: A partial skeleton lacking the skull, with elements of the front and hind limbs, as well as the pelvis and two caudal vertebrae. A cladistic analysis by Ezcurra indicated that Chromogisaurus was a member of a clade basal sauropodomorphs , the Guaibasauridae , together with Guaibasaurus , the disputed Agnosphitys , Panphagia and Saturnalia . Within Guaibasauridae, it forms a smaller clade with its sister taxon Saturnalia ,
30-678: Is Chromogisaurus novasi . The generic name is derived from Greek chroma , "colour", and gè , "earth", a reference to the Valle Pintado , the "Painted Valley". The specific name honours Fernando Emilio Novas . The holotype , PVSJ 845, was found in the Cancha de Bochas Member of the Ischigualasto Formation , dating to the Carnian . This makes Chromogisaurus one of the oldest known dinosaurs . The specimen consists of
40-667: Is alternatively considered its own genus or a synonym of Plateosaurus . Plateosauridae, which was first named by Othniel Charles Marsh in 1895, is a stem-based taxon and it was defined by Sereno, 1998 as all animals more closely related to Plateosaurus engelhardti than to Massospondylus carinatus . Galton and Upchurch, 2004 proposed the following definition: all animals more closely related to Plateosaurus engelhardti than to Massospondylus carinatus and Yunnanosaurus huangi . Yates, 2007 defined it as all animals more closely related to Plateosaurus engelhardti than to Diplodocus longus . Recent cladistic analyses suggest that
50-583: Is an extinct genus of saturnaliid sauropodomorph which existed in Argentina during the Late Triassic ( Carnian ) period. It is from the Cancha de Bochas, Valle Pintado member of the Ischigualasto Formation . It was a herbivore about 2 metres (6 ft 7 in) in length, and was optionally quadrupedal. Chromogisaurus was first named by Martín Daniel Ezcurra in 2010, and the type species
60-666: Is the major groundwater-bearing unit of the Upper Karoo Group. Prosauropod Plateosauridae is a family of plateosaurian sauropodomorphs from the Late Triassic of Europe , Greenland , Africa and Asia . Although several dinosaurs have been classified as plateosaurids over the years, the family Plateosauridae is now restricted to Plateosaurus , Yimenosaurus , Euskelosaurus , and Issi . In another study, Yates (2003) sunk Sellosaurus into Plateosaurus (as P. gracilis ). Gresslyosaurus
70-1126: The Cabora Bassa Basin . The formation is dated at 200 to 190 Ma . The Forest Sandstone is the penultimate formation in the Upper Karoo Group of the Karoo Supergroup , lying above the Pebbly Arkose Formation and below the Batoka Formation . In the Thuli Basin it is sometimes referred to as the Samkoto Formation. The Forest Sandstone has been correlated to the Clarens Formation of the Great Karoo Basin in South Africa. The Forest Sandstone
80-538: The cladogram below: Chromogisaurus Pampadromaeus Panphagia Saturnalia Guaibasaurus Pantydraco Thecodontosaurus Efraasia Plateosauravus Ruehleia Macrocollum Unaysaurus Issi Plateosaurus gracilis Plateosaurus trossingensis Riojasaurus Eucnemosaurus Massopoda [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] Chromogisaurus Chromogisaurus
90-426: The clade Prosauropoda , which was named by Huene in 1920 and was defined by Sereno, 1998 as all animals more closely related to Plateosaurus engelhardti than to Saltasaurus loricatus , is a synonym of Plateosauridae as both contain the same taxa. Plateosauridae was recovered as a monophyletic group in the large phylogenetic analysis of early dinosaurs that was presented by Baron, Norman & Barrett (2017) in
100-468: The journal Nature . In this analysis, the group was found to be sister to Massopoda within the clade Plateosauria . The 2021 study by Beccari et al . describing Issi saaneq recovered it as the sister taxon of Plateosaurus . Their phylogenetic analyses also recovered Macrocollum and Unaysaurus within the Plateosauridae. The results of their phylogenetic analyses are shown in
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