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The Walcott–Rust quarry is an excellent example of an obrution (rapid burial or "smothered") Lagerstätten. Unique preservation of trilobite appendages resulted from early consolidation (cementation) of the surrounding rock, followed by spar filling of the interior cavity within the appendages. The presence of so many well preserved trilobites in one location alone qualifies the beds as an exceptional trilobite site, but the beds are further distinguished as the source of the first trilobites for which appendages were definitively described.〔 ==Historical overview== By 1860 William Palmer Rust (1826–1897) and his father Hiram were actively excavating fossils from quarries on the family farm originally opened for building stone.〔() William Rust biography from Harvard〕 1870 saw Charles Doolittle Walcott working a new trilobite locality in Upper Ordovician limestones on a creek near the Rust farm, where Walcott had recently moved. Walcott and Rust began to quarry the site with Walcott marrying Rust's daughter Laura Ann on January 9, 1872. In 1873 Walcott and Rust sold their collections to Louis Agassiz at the Museum of Comparative Zoology, Harvard University. At this meeting between Walcott and Agassiz, Walcott mentioned that he had seen evidence of appendages and soft tissue, which Agassiz recommended he pursue. Discovery of soft body preservation at the Walcott–Rust quarry pre-dates Walcott's discovery of the more famous Burgess Shale lagerstätte by 40 years. Walcott left the area and active working of the quarry in 1876 (his wife Lura Ann died of tuberculosis on January 23, 1876) although he returned for brief periods throughout his career. In 1876/7 Walcott published several papers on trilobite appendages, the first documentation of these features. In 1879 Walcott took up his appointment with the USGS and sold the fossils he and Rust had collected between 1873 and 1879 to Alexander Agassiz at the Museum of Comparative Zoology. Rust and his friends continued to extract and sell specimens from the quarry until Rust's death in 1897. It is estimated that over the years were excavated. The old fossil quarry site was reopened in 1990 by Thomas E. Whiteley (also involved in the rediscovery of Beecher's Trilobite Bed) and extensively re-examined.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Walcott–Rust quarry」の詳細全文を読む スポンサード リンク
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