English paleontologist Harry Govier Seeley, who described the genus, first mentioned the
holotype (SMC B53408), a maxilla or upper jaw bone, in 1869. Seeley was at the time compiling a catalogue of the fossils of the
Woodwardian Museum. Part of these formed the Forbes Collection that after the death of
James Forbes-Young had in 1862 been donated to the
University of Cambridge by his sons Charles Young and Henry Young. The
provenance of this particular bone from that collection was unknown; first believed to be found near
Tilgate from a Lower Cretaceous
stratum, it was later thought to have been discovered somewhere near the coast of Yorkshire in a Jurassic layer. Seeley initially assumed that it was referable to
Iguanodon, and named it
Iguanodon Phillipsii. The
specific name honoured geology professor
John Phillips. The five inch long fragment lacked the teeth, only seventeen empty tooth sockets being visible. By 1875, after subsequent preparation had uncovered the replacement teeth within the jaw bone, Seeley had recognized that it was different, and so gave it the generic name
Priodontognathus. The name is derived from Greek '
, "saw", ', "tooth" and '''', "jaw", in recognition of the form of its teeth. Because the replacement teeth had not yet erupted, their serrations had not been worn down and many sharp denticula could be seen, shaped as the points of a saw. Because armored dinosaurs were very poorly known at the time, he had little to compare it to, and in light of this it is not too surprising that he later, in 1893, had it mixed up with the
stegosaurian
Omosaurus (now
Dacentrurus); although at least one author, Baron
Franz Nopcsa, recognized that it was not, and assigned it to "Acanthopholididae", which we would recognize as
Nodosauridae.
Alfred Sherwood Romer also recognized that it was an ankylosaurian, although he synonymized it with
Hylaeosaurus.
Peter Galton reassessed the genus in 1980 and established that it was a distinct genus, which he compared to
Priconodon and
Sauropelta and assigned to
Nodosauridae. While his assessment of it as a type of ankylosaurian has been accepted, his belief that it was valid was not, and it has been usually considered a dubious genus of uncertain ankylosaurian affinities since then.
"Omosaurus" phillipsii As mentioned, Seeley named a femur
Omosaurus phillipsii in 1893, which has become confused with this animal, due to being discussed in the same article (and considered to possibly be the same genus), and due to them having the same specific name.
Omosaurus phillipsii, now known as "
Dacentrurus"
phillipsii or "Omosaurus"
phillipsii (depending on how an author denotes dubious species), is a dubious
species of
stegosaurian from the
Malton Oolite Member of the
Corallian Oolite Formation,
Slingsby,
North Yorkshire. The femur, which is in three pieces, is that of a
juvenile. ==Paleobiology==