Moses Billings
With the development of the daguerreotype in the 1840s, the role of the portrait painter declined in general, because it was now much easier and much cheaper to have one's likeness presented in a visual format. While many portrait painters lost business in competition with the daguerreotype, Billings instead began to produce daguerreotype prints himself. It is not known exactly which prints were made by Moses Billings, as daguerreotypes were usually signed, when signed at all, along the side of the plate. Due to the traditional storing methods of daguerreotype plates, even this signature usually quickly became illegible. However, it has been generally noted, or at least hypothesized, that his daguerreotype prints showed a level of talent and artistry above that of amateur daguerreotypists. Though it is not known exactly which prints were his, it is known that he had largely abandoned the process by the 1850s. Even after he stopped making daguerreotypes, he did continue to paint people's portraits on canvas.
Dacentrurus
The holotype, BMNH 46013, was found in a layer of the Kimmeridge Clay Formation dating from the late Kimmeridgian. The main nodule fragment contains the pelvis; a series of six posterior dorsal vertebrae, all sacrals and eight anterior caudal vertebrae; a right femur and some loose vertebrae. In all, thirteen detached vertebrae are present in the material. Also an almost complete left forelimb was contained by another loam clump. Additional elements include a partial fibula with calcaneum, a partial tibia, a right neck plate and a left tail spike.
Several other species would be named within the genus "Omosaurus". Part of the British Museum of Natural History collection was specimen BMNH 46321, a pair of spike bases found in the Kimmeridge Clay by William Cunnington near the Great Western Railway cutting near Wootton Bassett. These Owen in 1877 named "Omosaurus hastiger", the epithet meaning "spike-bearer" or "lance-wielder", the spikes by him seen as placed on the wrist of the animal. In 1887, John Whitaker Hulke named "Omosaurus durobrivensis" based on specimen BMNH R1989 found at Tanholt, close to Eye, Cambridgeshire, the specific name being derived from Durobrivae. (That specimen is sometimes mistakenly said to have been found at Fletton, Peterborough, Cambridgeshire, which is where Alfred Nicholson Leeds made most of his finds.) This in 1956 became the separate genus "Lexovisaurus". In 1893, Harry Govier Seeley named "Omosaurus phillipsii", based on a femur, specimen YM 498, the epithet honouring the late John Phillips. Seeley suggested this may be the same taxon as "Priodontognathus phillipsii" Seeley 1869, which has led to the misunderstanding, due to its having the same specific name, that "Priodontognathus" was simply subsumed by him under "Omosaurus". This interpretation however, is incorrect as both species have different holotypes. "Omosaurus leedsi" is a "nomen nudum" used by Seeley on a label for CAMSM J.46874, a plate found in Cambridgeshire, the epithet honouring Alfred Nicholson Leeds. In 1910 Friedrich von Huene named "Omosaurus vetustus", based on specimen OUM J.14000, a femur found in the west bank of Cherwell River, the epithet meaning "the ancient one". In 1911 Franz Nopcsa named "Omosaurus lennieri", the epithet honouring Gustave Lennier, based on a partial skeleton in 1899 found in the Kimmeridgian "Argiles d'Octeville" near in Normandy, France. The specimen would be destroyed during the allied bombing of Caen in 1944.
Even as the last two "Omosaurus" species were named, it had become known that the name "Omosaurus" had been preoccupied by a "crocodilian" (in fact a phytosaur), "Omosaurus perplexus" Leidy 1856. In 1902 Frederick Augustus Lucas renamed the genus into "Dacentrurus". The name is derived from Greek δα~, "da~", "very" or "full of", κέντρον, "kentron", "point", and οὐρά, "oura", "tail". Lucas only gave a new combination name for the type species "Omosaurus armatus": "Decentrurus armatus", but in 1915 Edwin Hennig moved most "Omosaurus" species to "Dacentrurus", resulting in a "Dacentrurus hastiger", "Dacentrurus durobrivensis", "Dacentrurus phillipsi" and a "Dacentrurus lennieri". Nevertheless, it would be common for researchers to use the name "Omosaurus" instead until the middle of the twentieth century. "D. vetustus", earlier indicated as "Omosaurus" ("Dacentrurus") "vetustus" by von Huene, was included with "Lexovisaurus" as a "Lexovisaurus vetustus" in 1983, but that assignment was rejected with both editions of the "Dinosauria", and "O. vetustus" is now the type species of "Eoplophysis".