Taxonomy
The Dodo has been variously declared a small ostrich, a rail, an albatross, and a vulture. In 1842, Johannes Theodor Reinhardt proposed that Dodos were ground pigeons, based on studies of a Dodo skull he had discovered in the royal Danish collection at Copenhagen. This view was met with ridicule, but was later supported by Hugh Edwin Strickland and Alexander Gordon Melville in their 1848 monograph The Dodo and Its Kindred, which attempted to separate myth from reality. After dissecting the preserved head and foot of the specimen at the Oxford University Museum and comparing it with the few remains then available of the extinct Rodrigues Solitaire (Pezophaps solitaria) they found that the two were closely related. Strickland stated that although not identical, these birds shared many distinguishing features of the leg bones, otherwise known only in pigeons.
The Dodo was anatomically similar to pigeons in many features. Strickland pointed to the very short keratinous portion of the beak, with its long, slender, naked basal part. Other pigeons also have bare skin around their eyes, almost reaching their beak, as in Dodos. The forehead was high in relation to the beak, and the nostril was located low on the middle of the beak and surrounded by skin, a combination of features shared only with pigeons. The legs of the Dodo were generally more similar to those of terrestrial pigeons than of other birds, both in their scales and in their skeletal features. Depictions of the large crop hinted at a relationship with pigeons, in which this feature is more developed than other birds. Pigeons generally have very small clutches, and the Dodo is said to have laid a single egg. Like pigeons, the Dodo lacked the vomer and septum of the nostrils, and it shared details in the mandible, the zygomatic bone, the palate and the hallux. The Dodo differed from other pigeons mainly in the small size of the wings and the large size of the beak in proportion to the rest of the cranium.
Throughout the 19th century, several species were classified as congeneric with the Dodo, including the Rodrigues Solitaire and the Réunion Solitaire, as Didus solitarius and Raphus solitarius, respectively (Didus and Raphus being names for the Dodo genus used by different authors of the time). An atypical 17th-century description of a Dodo and bones found on Rodrigues, now known to have belonged to the Rodrigues Solitaire, led Abraham Dee Bartlett to name a new species, Didus nazarenus, in 1852. Based on Solitaire remains, it is now a synonym of that species. Crude drawings of the Red Rail of Mauritius were also misinterpreted as Dodo species, Didus broeckii and Didus herberti.
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