Specimens of 'saurian animals' were first noted in autumn, 1834 from the limestone quarries of Durdham Down, Clifton. At that time, Clifton, located in the county of Somerset, was a separate town from Bristol, which was part of Gloucestershire. However, the two towns adjoined, and Clifton was formally incorporated into the city of Bristol in the 1830s.

These quarries are now largely infilled or built over, and there has been some confusion over their exact location, and the location of the dinosaur finds. The first indication of the site is given as 'the quarry east of Durdham Down' by Anonymous (1835). Information in papers by Etheridge (1870) and Moore (1881) allowed David Whiteside in 1982 to confirm this and identify the site at the east end of a series of old quarries, and located beside a set of steps called Quarry Steps (See map; National Grid Reference, ST 572747; Benton and Spencer, 1995, p. 89).

Map of north Clifton and the Downs, Bristol, showing five suggested locations of the Thecodontosaurus find in 1834, numbered 1-5. The key map (top left) shows the distribution of Triassic exposured in England and Wales, and the locations of Bristol and London.

Etheridge (1870, figs. 4, 5) gave two drawings showing the reptile deposit at about 320 ft. above mean sea level and noted (Etheridge, 1870, p. 188) that 'the spot where these remains were found is no longer recognizable or determinable, having been many years ago quarried away, and the site built upon. Fortunately, we have records of the exact position; and many years since, W. Sanders... most accurately determined the site of the reptilian quarry on the eastern side of Durdham Down.' Moore (1881, p. 72) confirmed this, mentioning specifically a place known as 'The Quarry and The Quarry Steps' and states 'Looking from it [the platform of Quarry Steps], along the Down escarpment to the west, the eye takes in Bellevue Terrace [= 'Belgrave Terrace'; numbers 19-23 Upper Belgrave Road], on the edge of the Down; and it was between these houses and the quarry, a distance probably of 200 yards, along the same face of limestone, and on the same horizon, that the deposit containing the Thecodontosaurian remains was found. Unfortunately the precise spot is unknown... and built over.' This is only partly true, as Etheridge (1870) had first-hand evidence from people who had witnessed the discoveries. First, he relied on testimony from William Sanders (1799-1875), a keen amateur geologist who lived in Clifton, and who from 1835 onwards produced a detailed geological map of the whole area (Clark, 2004). Further, Etheridge (1870, fig. 6) was also able to reproduced a sketch he had been given years before by Samuel Stutchbury, showing the position of the bones in the cave breccia as they were being removed.

Huene (1908a, p. 191) seemingly misunderstood Moore, naming the site of discovery as Avenue Quarry at the end of Avenue Road, but Moore (1881) had identified this Avenue Quarry as distinct from the Thecodontosaurus find site just noted, as a location 680 yards away from Quarry Steps and terminating a transect of workings that hosted fissures of different ages. Further, Perceval (1907, p. 5) suggested a third possible location for the 1834 Thecodontosaurus discovery: 'The exposure of rock from which they were obtained used to be visible on the west side at the south end of Worrall Road. This exposure is represented in the maps that accompanied Wright's Bristol Directories of the years 1870 to 1874. At page 111 of Arrowsmith's Dictionary of Bristol, 1884, the locality is thus described: 'Reptilian remains were found some years ago in a dike of new red conglomerate, near Lower Belgrave Road Durdham Down.' The exposure in Worrall Road is no longer visible, having apparently been built over.' This is the further, western, end of the Worrall Road quarries, and yet it in no way matches the first-hand evidence from Sanders and Stutchbury reported by Etheridge (1870).

As noted by Benton et al. (2000) and Galton (2007), there are five quarry sites around this area (see map):

1. Worrall Road quarries, east end, extending some 300 m from the eastern limit, at Quarry Steps/ High Street to Sutherland Place;
2. Worrall Road quarries, west end, lying to the west of Sutherland Place (='Sunderland Place' on some old maps), and extending to the end of Worrall Road, where it joins Upper Belgrave Road (Perceval's, 1907, suggested site);
3. Down (the A4176 road) opposite the end of The Avenue, a residential street;
4. Redland House Quarry, lying north of the roundabout at the junction of the A4176 and A4018. Quarrying had ended in 1876, and the site was used in turn as a sports and recreation centre by music company Duck, Son and Pinker, then after 1946 as a public recreation site owned by John Ley, then from 1953 to 1983 as the Locarno (renamed Tiffany's) Dance Hall, and finally a BUPA private hospital, now named the Spire. This quarry is located within the Redland district of Bristol, and is sometimes termed the 'Redland quarry' (Galton, 2007, fig. 1), lying as it does some 100 m west of the former Redland House.
5. Durdham Down quarries, lying under grass within the Downs today, to the northwest of Upper Belgrave Road; these are remains of former lead workings, known formerly as 'the Dumps' (Ralph, 1961).

The exact dates of operation of the various quarries is not clear, but it is interesting that there is no sign of the Worrall Road quarries, nor indeed of Worrall Road, on a famous 1828 map (Ashmead, 1828). The line of Worrall Road was represented at the east end by Caroline Row, which joined what is now the upper part of Whiteladies Road, called Blackboy Hill, but it curved substantially and meandered westwards as an open country road.

The site of discovery of Thecodontosaurus, according to the testimony of Etheridge (1870) and Moore (1881) may still be seen, largely overgrown, forming a cliff behind a block of flats, and with an old set of stone steps (Quarry Steps) descending beside it. The topotype quarry contains at least one fissure with a lithology similar to that of the bone-bearing matrix, but all bones appear to have been quarried away.

Some confusion might arise from the slightly later discovery of a bone-bearing fissure on Durdham Down, but this time a Pleistocene fissure containing fragmentary bones of ice age mammals, found early in 1842, and in which David Williams took an interest. He had begun his geological career in the 1820s with studies on the famous Mendips bone caves at Banwell, Holwell, Bleadon, and Uphill. However, Stutchbury and Riley carried out the excavations, and specimens of rhinoceros, elephant, horse, hyaena, and bear were extracted for the Museum (Stutchbury, 1842; Wilson, 1886, 1890). The exact location of the fissure is unknown, but it seems to have been in a quarry on the south side of Stoke Road, at map ref. ST 567752; the fauna indicates an Ipswichian age (Hawkins and Tratman, 1977).

• Anonymous, 1835. Saurian remains in the Magnesian Conglomerate of Bristol. West of England Journal of Science and Literature 1, 84-85.
• Ashmead, G., 1828. A Plan of the City of Bristol and its Suburbs, Reduced from the Original Survey of the late J. Plumley With additions by Geo. C. Ashmead. Ashmead, Bristol.
• Benton, M.J., Juul, L., Storrs, G.W., Galton, P.M., 2000. Anatomy and systematics of the prosauropod dinosaur Thecodontosaurus antiquus from the Upper Triassic of southwest England. Journal of Vertebrate Paleontology 20, 77-108.
• Benton, M.J., Spencer, P.S., 1995. Fossil Reptiles of Great Britain. Chapman and Hall, London, 386 pp.
• Clark, R.D., 2004. Sanders, William. Oxford Dictionary of National Biography. http://10.1093/ref:odnb/24623.
• Etheridge, R., 1870. On the geological position and geographical distribution of the reptilian or dolomitic conglomerate of the Bristol area. Quarterly Journal of the Geological Society of London 26, 174-192.
• Galton, P.M., 2007. Notes on the remains of archosaurian reptiles, mostly basal sauropodomorph dinosaurs, from the 1834 fissure fill (Rhaetian, Upper Triassic) at Clifton in Bristol, southwest England. Revue de Paléobiologie 26, 505-591.
• Hawkins, A.B., Tratman, E.K., 1977. The Quaternary deposits of the Mendip, Bath and Bristol areas; including a reprinting of Donovan's 1954 and 1964 bibliographies. Proceedings of the University of Bristol Spelaeological Society 14, 197-232.
• Huene, F. von, 1908a. Die Dinosaurier der europäischen Triasformationen mit Berücksichtigung der aussereuropäischen Vorkommnisse. Geologische und Paläontologische Abhandlungen. Supplement 1, 1-419.
• Moore, C., 1881. On abnormal geological deposits in the Bristol district. Quarterly Journal of the Geological Society of London 37, 67-82.
• Perceval, S.G., 1907. On certain collections in the Bristol Museum. How they originated. Bristol Times and Mirror, Jan. 5th (author's reprint, 7 pp.).
• Ralph, E., 1961. The Downs 1861-1961. The City of Bristol Printing and Stationary Dept.
• Stutchbury, S., 1842. [Report of a lecture to the Philosophical Society.] Felix Farley's Bristol Journal 31st December, 1842.
• Wilson, E., 1886. The bone-cave or fissure of Durdham Down. Proceedings of the Bristol Naturalists' Society, New Series 5, 31-45.
• Wilson, E., 1890. VI.--Fossil types in the Bristol Museum. Geological Magazine, Decade III 7, 363-372.

The paper

Benton, M.J. 2012. Naming the Bristol dinosaur, Thecodontosaurus: politics and science in the 1830s. Proceedings of the Geologists' Association 123, 766-778. Download pdf of the paper.