The Lufeng Formation (formerly Lower Lufeng Series ) is a Lower Jurassic sedimentary rock formation found in Yunnan , China . It has two units: the lower Dull Purplish Beds / Shawan Member are of Hettangian age, and Dark Red Beds / Zhangjia'ao Member are of Sinemurian age. It is known for its fossils of early dinosaurs . The Dull Purplish Beds have yielded the possible therizinosaur Eshanosaurus , the possible theropod Lukousaurus , and the " prosauropods " "Gyposaurus" sinensis , Lufengosaurus , Jingshanosaurus , and Yunnanosaurus . Dinosaurs discovered in the Dark Red Beds include the theropod Sinosaurus triassicus , the "prosauropods" "Gyposaurus", Lufengosaurus , and Yunnanosaurus , indeterminate remains of sauropods , and the early armored dinosaurs Bienosaurus and Tatisaurus .
11-1240: Clevosaurus Indeterminate Yunnan Dianchungosaurus D. lufengensis Yunnan Dark Red Beds Formerly considered an ornithopod dinosaur. Indeterminate ornithopod remains Yunnan. Dark Red Beds. Bienosaurus B. lufengensis Yunnan Dark Red Beds A right "[d]entary with teeth," with additional cranial fragments such as a partial frontal. These specimens are catalogued as IVPP V 9612. The dentary preserves 11 teeth or roots with two additional empty alveoli. Tatisaurus T. oehleri Yunnan Dark Red Beds "Isolated dentary." Chuxiongosaurus C. lufengensis Yunnan "Skull Gyposaurus G. sinensis Yunnan "[Two] skeletons, [one] with partial skull, [two] partial skeletons, [three] skull fragments, adult." Fulengia F. youngi Yunnan "Skull." Jingshanosaurus J. xinwaensis Yunnan "Complete skeleton with skull, adult." " Kunmingosaurus " "K. wusdingensis" Yunnan nomen nudum Lufengosaurus L. huenei Yunnan "(including Gyposaurus sinensis , L. magnus )" L. magnus Yunnan Tawasaurus T. minor Yunnan Yunnanosaurus Clevosaurus See text Clevosaurus (meaning "Gloucester lizard")
22-596: Is an extinct genus of rhynchocephalian reptile from the Late Triassic and the Early Jurassic periods . Species of Clevosaurus were widespread across Pangaea , and have been found on all continents except Australia and Antarctica. Five species of Clevosaurus have been found in ancient fissure fill deposits in south-west England and Wales, alongside other sphenodontians, early mammals and dinosaurs. In regards to its Pangaean distribution, C. hadroprodon
33-611: Is at the first appearance of the ammonite genera Vermiceras and Metophioceras in the stratigraphic record. A global reference profile ( GSSP or golden spike ) for the Sinemurian Stage is located in a cliff north of the hamlet of East Quantoxhead , 6 kilometers (3.7 mi) east of Watchet , Somerset , England . The top of the Sinemurian (the base of the Pliensbachian) is at the first appearances of
44-537: Is the oldest record of a sphenodontian from Gondwana, though its affinity to Clevosaurus has been questioned. The first species of Clevosaurus to be described was C. hudsoni , which was described by William Elgin Swinton in 1939 from a fissure fill deposit in Cromhall Quarry ( Magnesian Conglomerate Formation ) in the county of Gloucestershire , England, with the name of the county lending its name to
55-569: The Blue Lias . The Sinemurian Stage was defined and introduced into scientific literature by French palaeontologist Alcide d'Orbigny in 1842. It takes its name from the French town of Semur-en-Auxois , near Dijon . The calcareous soil formed from the Jurassic limestone of the region is in part responsible for the character of the classic Sancerre wines . The base of the Sinemurian Stage
66-979: The Sinemurian aged Lufeng Formation of China ( C. mcgilli, C.wangi and C. petilus ) are now considered indeterminate within the genus. Indeterminate remains are also known from the Stormberg Group (either Elliot or Clarens Formation ) of South Africa, dating to the Hettangian. Below is a cladogram of the relationships within Clevosauridae based on the phylogenetic analysis of Hsiou et al. (2015): Polysphenodon mulleri Brachyrhinodon taylori Clevosaurus sp. (South Africa) Clevosaurus convallis Clevosaurus hudsoni Clevosaurus petilus Clevosaurus bairdi Clevosaurus mcgilli Clevosaurus wangi Clevosaurus brasiliensis Clevosaurus cambrica "Clevosaurus" latidens
77-656: The geologic timescale , the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series . It spans the time between 199.5 ±0.3 Ma and 192.9 ±0.3 Ma (million years ago). The Sinemurian is preceded by the Hettangian and is followed by the Pliensbachian . In Europe the Sinemurian age, together with the Hettangian age, saw the deposition of the lower Lias , in Great Britain known as
88-486: The base of the teeth sit deeply within the jaw bones, which is not known of in any other rhynchocephalian. Species of Clevosaurus were likely insectivorous. Biomechanical modelling suggests that they had high enough tooth pressures and strong enough bite force to crush chitin , indicating that they had the ability to feed on thick-shelled beetles as well as possibly small vertebrates. At least 9 species of Clevosaurus are considered valid: The three species known from
99-808: The genus. Another notable specimen was discovered in 1953 in Cromhall Quarry alongside the holotype of Cryptovaranoides microlanius . Species of Clevosaurus varied in body size, with Clevosaurus sectumsemper having an estimated total length of 12 centimetres (4.7 in), while C. hudsoni had a total length of around 25 centimetres (9.8 in) . The skull length could range from as little as 1.4 centimetres (0.55 in) in C. sectumsemper and up to 4 centimetres (1.6 in) in C. hudsoni . Notable for their greatly reduced number of teeth (3-6 per jaw quadrant), broad skulls and shortened snouts. The teeth of european clevosaurs tended to be mesio-distally elongated, blade-like, and occluded precisely with
110-416: The opposite pair of teeth, leaving conspicuous diagonal wear facets and acting as a self-sharpening cutting surface. However, the teeth of C. brasiliensis have a very different morphology with no diagonal wear facets, the teeth of the dentary are all conical excluding the posterior-most tooth which can be up to three-times bigger than any of the other teeth, they also have a unique form of implantation, where
121-1287: Was recovered outside of Clevosauridae, as the sister taxon of Opisthodontia . It was subsequently assigned to a new genus, Fraserosphenodon , in 2018. Clevosaurus is considered to be a member of the group Eusphenodontia by the groups definition, due to it possessing characters not shared with more primitive sphenodontians. By definition, it is excluded from Neosphenodontia. Position of Clevosaurus within Rhynchocephalia, after DeMar et al. 2022. Younginia capensis Prolacerta broomi Sophineta cracoviensis Pristidactylus Eichstaettisaurus schroederi Megachirella wachtleri Marmoretta oxoniensis Gephyrosaurus bridensis Diphydontosaurus avonis Planocephalosaurus robinsonae Rebbanasaurus jaini Godavarisaurus lateefi Theretairus antiquus Polysphenodon mulleri Opisthiamimus gregori Clevosaurus convallis Clevosaurus brasiliensis Clevosaurus hadroprodon Clevosaurus bairdi Clevosaurus hudsoni Clevosaurus cambrica Brachyrhinodon taylori Colobops noviportensis Sphenodon punctatus Cynosphenodon huizachalensis Sphenovipera jimmysjoyi Sinemurian In
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