Phobetor (pterosaur)

''Noripterus'' (meaning "lake wing" from Mongolian ''nuur'', "lake" and Greek ''pteron'', "wing") is a genus of dsungaripterid pterodactyloid pterosaur from Lower Cretaceous-age Lianmuqin Formation in the Junggar Basin of Xinjiang, China. It was first named by Yang Zhongjian (also known as C.C. Young in older sources) in 1973. Additional fossil remains have been recovered from Tsagaantsav Svita, Mongolia.

Description

The first, holotype specimen of ''Noripterus'' (IVPP V.4062, type locality IVPP 64045) preserved the front part of the skull and lower jaws, vertebrae, and partial limbs and pelvis. ''Noripterus'' was quite similar to the contemporaneous ''Dsungaripterus'', though it was estimated to be a third shorter. It has long narrow neck vertebrae and, like ''Dsungaripterus'', a crest and no teeth in the front of the lower jaw. The teeth that are present are well-developed and spaced fairly far apart. The sharp snout is straight and not pointed upwards as with ''Dsungaripterus''.

Classification

Because of its similarity to ''Dsungaripterus'', ''Noripterus'' has been assigned to the family Dsungaripteridae.Unwin, David M. (2003) "On the phylogeny and evolutionary history of pterosaurs", in ''Evolution and Palaeobiology of Pterosaurs'', 139-190.

The genus ''Phobetor'', was in 1982 originally described by Natasha Bakhurina as a species of ''Dsungaripterus'' (''D. parvus''), based on a single lower leg bone, PIN 3953. The discovery of more remains later, among which an almost complete skull, GIN 100/31, was reason for Bakhurina to name ''D. parvus'' in 1986 as a separate genus, and the species name became ''Phobetor parvus''. However, the genus name ''Phobetor'' was already being used as a junior synonym of a species of sculpin, namely, the arctic staghorn sculpin, '' Gymnocanthus tricuspis'' (synonym "''Phobetor tricuspis''" Krøyer, 1844) and thus unavailable. In 2009, Lü and colleagues re-examined much of the known dsungaripterid fossil material, and found that "Phobetor" was indistinguishable from ''Noripterus'', causing them to refer to it as a junior synonym.Lü, J., Azuma, Y., Dong, Z., Barsbold, R., Kobayashi, Y., and Lee, Y.-N. (2009), "New material of dsungaripterid pterosaurs (Pterosauria: Pterodactyloidea) from western Mongolia and its palaeoecological implications." ''Geological Magazine'', 146(5): 690-700.

Assigning the "Phobetor" material to ''Noripterus'' increases the known size of the latter as it indicates a maximum wingspan of .

Below is a cladogram showing the results of a phylogenetic analysis presented by Andres and colleagues in 2014. They recovered ''Noripterus'' within the Dsungaripteridae, more specifically within its own subfamily called Noripterinae. Their cladogram is shown below.

In 2019, a different topology, this time by Kellner and colleagues, was published. In this study, ''Noripterus'' was recovered outside the Azhdarchoidea, within the larger group Tapejaroidea, sister taxon to ''Dsungaripterus''. The cladogram of the analysis is shown below.

Paleobiology and ecology

Dsungaripterids like ''Noripterus'' are interpreted as adapted for feeding on shellfish or other hard foodstuffs, with long narrow toothless beak tips for probing and picking up suitable prey, and robust teeth farther back for cracking shells. The skulls of these animals are more robust than those of other pterosaurs, as well as their limbs and vertebrae.

''Noripterus'' lived in the same time and place as the larger ''Dsungaripterus'', in formations that indicate the presence of extensive inland lake systems. Because ''Noripterus'' had a more lightly built skull with weaker, more slender teeth than its larger contemporary, it is likely that the two pterosaurs occupied separate ecological niches.

Like most dsungaripteroids, ''Noripterus'' was well adapted to a terrestrial lifestyle, bearing thick bone walls and stouty bodily proportions.Witton, Mark (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. p. 51. .

See also

* List of pterosaur genera
* Timeline of pterosaur research

References

{{Portal bar, Paleontology, Cretaceous, China

Dsungaripterids
Early Cretaceous pterosaurs of Asia
Taxa named by Yang Zhongjian
Fossil taxa described in 1973