In the autumn of 1834, surgeon Henry Riley (1797–1848) and the curator of the Bristol Institution, Samuel Stutchbury (15 January 1798 – 12 February 1859), began to excavate "saurian remains" at the quarry of Durdham Down, at Clifton, presently a part of Bristol, which is part of the Magnesian Conglomerate. In 1834 and 1835, they briefly reported on the finds. They provided their initial description in 1836, naming two new genera: "Palaeosaurus" and "Thecodontosaurus". In 1836 Riley and Stutchbury briefly and informally published on two new fossil teeth (the holotype tooth of "P. platyodon" is listed under BRSMG *Ca7448/3 and the holotype tooth of "P. cylindrodon" is listed under BRSMG *Ca7449/4. Both are now listed under the latter species) found in or near the city of Bristol, England, which they called "Palaeosaurus cylindrodon" and "Palaeosaurus platyodon". Riley and Stutchbury did not mean to assign these species to Saint-Hilaire's genus of teleosaurids; they simply did not know the name had been used. "Thecodontosaurus" was also named in this publication. Only in 1840 do Riley and Stutchbury fully describe their two species of "Palaeosaurus", each based on a single sharp tooth from the Late Triassic Period. The spellings were then corrected to read "Paleosaurus cylindrodon" and "Paleosaurus platyodon".