page_title: Joggins Formation
section_title: 1852 survey
hierarchical_section_title: Joggins Formation / History / 1852 survey
caption_attribution_description: English: Portrait of John William Dawson
context_page_description: The Joggins Formation is a geologic formation in Nova Scotia. It preserves fossils dating back to the Carboniferous period, including Hylonomus, the earliest known reptile. In addition to fossils, the Joggins Formation was a valuable source of coal from the 17th century until the mid-20th century.
  The Joggins Formation's spectacular coastal exposure, the Joggins Fossil Cliffs at Coal Mine Point, was named a UNESCO World Heritage Site in 2008.
context_section_description: On Charles Lyell's third trip to the Americas, he made plans to visit Joggins a second time. He joined up with John William Dawson in Halifax and the two arrived at Joggins on 12 September 1852. The two measured 859.28 m (2819 ft, 2 in) of the cliffs, unaware that William Logan had already conducted a survey nine years earlier. While examining the cliffs, Lyell and Dawson discovered the fossil remains of a Dendrerpeton inside a fossil tree at Coal Mine Point. The tree had fallen from the cliffs, and has previously been entombed in Coal 15. Lyell and Dawson also discovered fossilized millipedes in the tree trunks, and fossils of the land snail Dendropupa. Among other things, the evidence of "reptile" (the distinction between reptiles and amphibians had yet to be made clear in 1852) fossils in strata of such age would disprove the argument made by proponents of catastrophism that Palaeozoic fishes had lost global dominance to the reptiles amid a worldwide catastrophe at the beginning of the Mesozoic era.
  Following the expedition, Charles Lyell took the fossils to be studied in Boston, where they were studied by Louis Agassiz and Jeffries Wyman at Harvard University. Agassiz first dismissed the remains as belonging to a coelacanth and Wyman believed they were those of a marine reptile related to Proteus anguinus, but after working the fossils out of the stone they'd been recovered in the scientists confirmed that the fossils represented bones from two reptiles: seven vertebrae and an ilium. At the time, only four tetrapod specimens had been recovered from coal formations around the world, meaning the eight bones recovered by Lyell and Dawson represented one-third of all Carboniferous tetrapod fossils. Lyell communicated this discovery to John W. Dawson in a letter on 6 November 1852, and publicly announced them in a series of lectures - the "Lowell lectures" - delivered at the Lowell Institute several weeks later. It was around this time that Lyell and Dawson became aware of William Logan's 1843 survey of the Joggins Formation, and on 16 December 1852 Lyell sent a request to Logan for a copy of his work to compare against their own. Logan insisted in a letter dated 10 January 1853 that he had already sent Lyell a copy years earlier when his report was first issued, illustrating the ambivalence the researchers had towards each other. Lyell and Dawson's discovery was relayed to the Geological Society in London on 19 January 1853, but unbeknownst to either of them a postscript had been added to their paper by Richard Owen, who had described and named the fossil as Dendrerpeton acadianum. In 1855, Dawson collected his and Lyell's research on Joggins into Acadian Geology, a text that drew serious interest from geologists across England and the United States.
  1855 also marked the only trip that Othniel Charles Marsh made to Joggins. Marsh had only recently begun to study at Yale University and was likely drawn to Joggins by the abundance of fossils described by Charles Lyell and John W. Dawson. Marsh returned to Yale with two vertebrae, which he described in 1862 as belonging to the marine reptile Eosaurus acadianus. Six years later Dawson commented that Marsh's description of Eosaurus closely resembled that of Ichthyosaurus, which at the time had only been found in European limestone such as the quarries of Lyme Regis, England. Vertebrate palaeontologists Donald Baird, Alfred Romer, and Robert L. Carroll have suggested that Marsh's Eosaurus actually represents fossils of Ichthyosaurus which Marsh purchased off someone who claimed they had been found at Joggins and passed the find off as his own discovery.
caption: Portrait of John William Dawson.
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