In the mid-to-late 19th century many dinosaur
taxa were named for isolated teeth; such
genera include
Trachodon,
Palaeoscincus, and
Troodon. Even before the
badlands of
North America started revealing the bones of
Tyrannosaurus,
teeth turning up in many localities in the Western
United States revealed the presence of large predatory dinosaurs. In 1856 Joseph Leidy had named fourteen teeth collected by
Ferdinand Vandeveer Hayden in 1854 and 1855 from the
Judith River Badlands of
Montana In 1866
Edward Drinker Cope chose three nonserrated teeth from the original
syntype series of fourteen as the
lectotypes of
Deinodon horridus. Leidy named these same three teeth
Aublysodon mirandus in 1868. The meaning of the generic name is uncertain because Leidy himself gave no
etymology or explanation of the intended meaning. It is possible the genus name is derived from Greek αὖ,
au, "again", "backwards", "contrariwise", βλύζω,
blyzo, "to spout", "to flow" and ὀδών,
odon, "tooth". The
specific name means "wonderful" or "strange" in
Latin. of the original syntypes of
Deinodon: the small tooth shown in figures 41-45 is ANSP 9535, the later
lectotype of
Aublysodon mirandus. Figures 37-40 show ANSP 9533, and figures 33 and 34 specimen ANSP 9534, the later lectotypes of
Deinodon horridus Because the name
Aublysodon mirandus was based on the same type, it was at first a
junior objective synonym of
Deinodon horridus, which latter name thus had priority. Cope in 1868 mistakenly thought the name
Deinodon was preoccupied by the snake
Dinodon and renamed
Deinodon horridus into an
Aublysodon horridus. If
Deinodon really had been preoccupied, this would have made
Aublysodon a valid genus. In 1899
Oliver Perry Hay pointed out Cope's mistake;
Aublysodon horridus is a junior objective synonym of
Deinodon horridus, just as
Aublysodon mirandus had been. However, in 1892
Aublysodon became an independent genus when
Othniel Charles Marsh further limited its type by choosing a single small nonserrated premaxillary tooth with a D-shaped cross-section, specimen ANSP 9535, as the lectotype of
Aublysodon mirandus. The two other teeth, ANSP 9533 and ANSP 9534, remained as the lectotypes of
Deinodon horridus. The names were thus separated. The tooth-based taxon
Aublysodon was a mystery for a long time since no further skeletal elements were found that could be assigned with certainty to the teeth. In the early twentieth century it was assumed by some workers that it represented a member of the
Ornithomimidae when it was not yet known this group was toothless.
Lawrence Morris Lambe in 1902 referred the tooth to
Struthiomimus; Hay in 1930 renamed
A. mirandus into
Ornithomimus mirandus, forgetting in that case
Aublysodon would have priority. Today it is known that similar teeth are found in juvenile specimens of
Daspletosaurus, and it is likely that teeth referred to
Aublysodon came from that genus. In October 2000, the type specimen of
Aublysodon went missing when being sent by
registered mail from the
Academy of Natural Sciences of Philadelphia to the
Field Museum of Natural History. Because of the presence of
Aublysodon-type teeth in other juvenile tyrannosaurines than
Daspletosaurus, such as those of
Tyrannosaurus, remains of which can also be found in Montana,
Thomas Carr no longer considered the name to represent a real biological taxon, but to be a
nomen dubium. a tooth of a juvenile tyrannosaur which has been synonymized with
Deinodon horridus. In 1892 Marsh named two more species:
Aublysodon amplus and
Aublysodon cristatus, respectively based on teeth YPM 296 and YPM 297; the latter has also been placed in the genus
Deinodon. In 1903
John Bell Hatcher renamed
Laelaps explanatus Cope 1876 into an
Aublysodon explanatus. This probably represents a tooth of
Saurornitholestes. In 1932
Friedrich von Huene classified a fragmentary skeleton named
Ornithomimus grandis by Marsh in 1890 as
Aublysodon grandis, but most later researchers have considered this a synonym of the Campanian tyrannosaur
Deinodon horridus. The first two are today seen as juvenile specimens of
Tarbosaurus; the last represents either a juvenile individual of
Tyrannosaurus or a separate genus
Nanotyrannus. The first skeletal material referred to an original
Aublysodon species was a partial
skull unearthed in
Jordan, Montana in 1966 and described by
Ralph Molnar in 1977/1978. The skull, specimen LACM 28741 at forty-five centimetres the length of an average human arm, bore pointed teeth attached to a long narrow snout. First thought to be a juvenile
Tyrannosaurus, then interpreted as a large dromaeosaurid, this "Jordan theropod" was given the name
Aublysodon molnaris by
Gregory S. Paul in 1988; in 1990 the name was by Paul emended to
Aublysodon molnari, applying the correct
genitive. It was made a separate genus
Stygivenator by George Olshevsky in 1995, but was later, in 2004, reinterpreted to be a juvenile
Tyrannosaurus rex by Thomas Carr and Tom Williamson. but later research by Thomas Carr and Tom Williamson first referred it to
Daspletosaurus In 1988 Paul also created another species when renaming
Shanshanosaurus huoyanshanensis Dong 1977 into
Aublysodon huoyanshanensis. ==Classification==