Additional subfossils were recovered during the 1860s, but more complete remains were found during the 1874 transit of Venus, since an observation station was located on the island. Many of these excavations were requested by the English ornithologists (and brothers) Alfred and Edward Newton, who used them to describe the osteology of the bird in detail. Thousands of bones were excavated, and mounted skeletons were composed from the remains of several specimens. Study of skeletal features by the Newtons indicated that the solitaire was morphologically intermediate between the dodo and ordinary pigeons, but differed from them in its unique carpal knob.