The genus was named in 2004 by
Michael Maisch,
Andreas Matzke and
Sun Ge. The
type species is
Lonchognathosaurus acutirostris. The genus name is derived from Greek , "lance", , "jaw" and , "lizard", in reference to the fact that it is a reptile with pointed jaws. The
specific name means "needle snout" in
Latin.
Lonchognathosaurus is based on
holotype SGP 2001/19, found near
Urumqi in the southern
Junggar Basin, the front portion of a skull and lower jaws that came from a large individual; the estimated length of the complete skull was about 400 mm (15.75 in). The point of the upper jaw, composed of the
premaxilla bones, was slender and had a needle-like tip. The
teeth of the upper jaw appeared far back of the tip, and were well-spaced, diminishing in size from front to back; they ended again in front of the nostrils. They were placed in tooth-sockets that had a low bony ridge but were not otherwise elevated from the jaw. Each
maxilla only had eight teeth, and the bottom margin of the upper jaw was straight (unlike in other pterosaurs where it is strongly curved). A
sagittal crest was present, with grooves and a
concave leading margin. Averianov
et al., (2022) described a distal fragment of the wing metacarpal from the Lower Cretaceous
Barremian-
Aptian age
Ilek Formation in West
Siberia,
Russia and identified it as cf.
Lonchognathosaurus sp., since it is "nearly identical to the wing metacarpal of
Lonchognathosaurus acutirostris." ==Classification==