Dendrorhynchoides was a genus of anurognathid pterosaur containing only the holotype species D. curvidentatus that is known from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebei Province, China.
The genus was first named Dendrorhynchus in 1998 by Ji Shu'an and Ji Qiang,[1] but that name proved to be preoccupied by a parasitic protozoan named in 1920 by David Keilin. It was therefore renamed in 1999.[2] The type species is Dendrorhynchoides curvidentatus. The genus name is derived from Greek dendron, "tree" and rhynkhos, "snout" in reference to it being assumed a tree-dweller and presumed a close relative of Rhamphorhynchus. The specific name means "curved-toothed" in Latin. A second species, D. mutoudengensis, was described in 2012, and moved to a new genus Luopterus in 2020.[3][4]
The genus is based on holotype GMV2128, a fossil originally discovered around 1995 and obtained by science from illegal fossil dealers who first prepared it. It consists of a near-complete skeleton of a subadult individual and is crushed. Most elements are present, exceptions include the sternum, the tail end, sacrals and the fourth phalanx of the wing finger. This specimen was originally thought to be from the Jianshangou Bed of the Yixian Formation, dated to about 124.6 million years old.[5] However, the specimen was obtained by amateur collectors and altered to contain a piece of a dromaeosaurid tail before being studied. David Hone and Lü Junchang in 2012 considered it more likely that the holotype of D. curvidentatus was actually found in the Middle Jurassic deposits; the authors note that all other Chinese anurognathids are Jurassic in age, and that Jeholopterus was also initially thought to be a Cretaceous taxon until subsequent studies established it to be from the Jurassic.[3]
In 2010 a second specimen, of a juvenile, was announced, that proved that a more elongated tail was present after all, albeit not so long as the faked tail of the holotype: about 85% of femur length.[6] This specimen eventually was designated as the holotype of a new species, Dendrorhynchoides mutoudengensis, by Hone and Lü in 2012.[3] The specimen was originally stored in the Guilin Geological Museum and designated GLGMV 0002; later it was moved to the Jinzhou Paleontological Museum and designated JZMP-04-07-3.[3] In 2020, Hone recognized that D. mutoudengensis was as distinct from D. curvidentatus as other species of anurognathids were from each other, and elevated it to a new genus and combination Luopterus mutoudengensis, named after the late Lü.[4]
Dendrorhynchoides had a wingspan of about forty centimetres, making it one of the smallest known pterosaurs. Of the type specimen, most parts of the skull have become detached so that its shape is difficult to determine, but it was generally short and broad. Eleven teeth have been preserved scattered throughout the matrix, that are recurved with a broader base and have a length of three millimetres. The authors identified lower jaws with a preserved length of fifteen millimetres. The cervical vertebrae are short and broad. Six dorsal vertebrae have been preserved, nine ribs and six belly ribs at the left side. The tail has a preserved length of five centimetres, but part of this is accounted for by a section that might have been added to enhance the value of the fossil. The tail vertebrae at the base, the authenticity of which is certain, are short.[1]