Specimens of Archaeopteryx the results of his investigation was a talk at the Royal Society in London in November, and was published as an abstract in the Proceedings of the Royal Society the following year. Here he considered the single feather described by von Meyer in 1861 and assigned the new skeleton the same genus. Owen speculated possible short- and long-tailed forms of "Archaeopteryx" and on these grounds assigned the London specimen the species name "macrura", meaning "long-tailed". Owen, who published a monograph on the specimen in 1863, generally considered the animal to be a bird despite describing its structure and proportions as
Archaeopteryx or trunk-climbing lifestyle. This has been interpreted as evidence of theropod ancestry. In 1988, Gregory S. Paul claimed to have found evidence of a hyperextensible second toe, but this was not verified and accepted by other scientists until the Thermopolis specimen was described. "Until now, the feature was thought to belong only to the species' close relatives, the deinonychosaurs." The Thermopolis Specimen was assigned to "Archaeopteryx siemensii" in 2007. The specimen is considered to represent the most complete and best-preserved "Archaeopteryx" remains yet. The discovery of an eleventh specimen was announced in 2011, and it was described in 2014. It