Chaoyangopteridae

The Chaoyangopteridae are a family of pterosaurs within the Azhdarchoidea.

Chaoyangopterids
Temporal range: Early Cretaceous, 125–120 Ma
↓
Possible Late Cretaceous record[1]
Holotype specimen of Jidapterus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Order: †Pterosauria
Suborder: †Pterodactyloidea
Clade: †Neoazhdarchia
Family: †Chaoyangopteridae
Lü et al., 2008
Type species
†Chaoyangopterus zhangi
Wang & Zhou, 2003
Genera

The clade Chaoyangopteridae was first defined in 2008 by Lü Junchang and David Unwin as: "Chaoyangopterus, Shenzhoupterus, their most recent common ancestor and all taxa more closely related to this clade than to Tapejara, Tupuxuara or Quetzalcoatlus".[2] Based on neck and limb proportions, it has been suggested they occupied a similar ecological niche to that of azhdarchid pterosaurs,[3] though it is possible they were more specialised as several genera occur in Liaoning, while azhdarchids usually occur by one genus in a specific location. The Chaoyangopteridae are mostly known from Asia, though the possible member Lacusovagus occurs in South America[4] and there are possible fossil remains from Africa, including the possible member Apatorhamphus.[5] Microtuban may extend the clade's existence into the early Late Cretaceous.[6]

Chaoyangopterids are distinguished from other pterosaurs by several traits of the nasoantorbital fenestra, a large hole on the side of the snout formed by the assimilation of the nares (nostril holes) into the antorbital fenestra. In members of this family, the nasoantorbital fenestra is massive, with the rear edge extending as far back as the braincase and jaw joint. The front edge is formed by a rod of bone known as the premaxillary bar, which is unusually slender in members of this family.[2]

Like their azhdarchid relatives, chaoyangopterids were terrestrial predators.[6][7]

Classification

Below is a cladogram following Andres and Myers (2013).[8]

 Neoazhdarchia 
 
 Thalassodromidae 
 

Thalassodromeus sethi

 
 
 

Tupuxuara leonardii

 
 

Tupuxuara longicristatus

 
 
 
 Dsungaripteridae 
 
 

Domeykodactylus ceciliae

 
 

Dsungaripterus weii

 
 
 
 

Noripterus complicidens

 
 

Noripterus parvus

 
 
 
 
 
 Chaoyangopteridae 
 

Eoazhdarcho liaoxiensis

 
 
 

Shenzhoupterus chaoyangensis

 
 
 

Chaoyangopterus zhangi

 
 

Jidapterus edentus

 
 
 
 
 
 

Radiodactylus langstoni

 
 Azhdarchidae 
 

Azhdarcho lancicollis

 
 
 

TMM 42489

 
 
 

Zhejiangopterus linhaiensis

 
 
 

Arambourgiania philadelphiae

 
 

Quetzalcoatlus northropi

 
 

Quetzalcoatlus sp.

 
 
 
 
 
 
 
 
gollark: Or Great Information Transfer.
gollark: Git stands for GIT Is Tremendous.
gollark: The stages of git clone are: Receive a "pack" file of all the objects in the repo database Create an index file for the received pack Check out the head revision (for a non-bare repo, obviously)"Resolving deltas" is the message shown for the second stage, indexing the pack file ("git index-pack").Pack files do not have the actual object IDs in them, only the object content. So to determine what the object IDs are, git has to do a decompress+SHA1 of each object in the pack to produce the object ID, which is then written into the index file.An object in a pack file may be stored as a delta i.e. a sequence of changes to make to some other object. In this case, git needs to retrieve the base object, apply the commands and SHA1 the result. The base object itself might have to be derived by applying a sequence of delta commands. (Even though in the case of a clone, the base object will have been encountered already, there is a limit to how many manufactured objects are cached in memory).In summary, the "resolving deltas" stage involves decompressing and checksumming the entire repo database, which not surprisingly takes quite a long time. Presumably decompressing and calculating SHA1s actually takes more time than applying the delta commands.In the case of a subsequent fetch, the received pack file may contain references (as delta object bases) to other objects that the receiving git is expected to already have. In this case, the receiving git actually rewrites the received pack file to include any such referenced objects, so that any stored pack file is self-sufficient. This might be where the message "resolving deltas" originated.
gollark: UPDATE: this is wrong.
gollark: > Git uses delta encoding to store some of the objects in packfiles. However, you don't want to have to play back every single change ever on a given file in order to get the current version, so Git also has occasional snapshots of the file contents stored as well. "Resolving deltas" is the step that deals with making sure all of that stays consistent.

References
  1. Ross A. Elgin and Eberhard Frey (2011). "A new azhdarchoid pterosaur from the Cenomanian (Late Cretaceous) of Lebanon". Swiss Journal of Geosciences. in press. doi:10.1007/s00015-011-0081-1.
  2. Lü, Junchang; Unwin, David M.; Xu, Li; Zhang, Xingliao (2008-09-01). "A new azhdarchoid pterosaur from the Lower Cretaceous of China and its implications for pterosaur phylogeny and evolution". Naturwissenschaften. 95 (9): 891–897. doi:10.1007/s00114-008-0397-5. ISSN 1432-1904. PMID 18509616.
  3. http://pterosaur.net/species.php
  4. Witton, Mark P. (2008). "A new azhdarchoid pterosaur from the Crato Formation (Lower Cretaceous, Aptian?) of Brazil". Palaeontology. 51 (6): 1289–1300. doi:10.1111/j.1475-4983.2008.00811.x.
  5. James McPhee; Nizar Ibrahim; Alex Kao; David M. Unwin; Roy Smith; David M. Martill (2020). "A new ?chaoyangopterid (Pterosauria: Pterodactyloidea) from the Cretaceous Kem Kem beds of Southern Morocco". Cretaceous Research. in press: Article 104410. doi:10.1016/j.cretres.2020.104410.
  6. Wilton, Mark P. (2013). Pterosaurs: Natural History, Evolution, Anatomy. Princeton University Press. ISBN 0691150613.
  7. Wen-Hao Wu; Chang-Fu Zhou; Brian Andres (2017). "The toothless pterosaur Jidapterus edentus (Pterodactyloidea: Azhdarchoidea) from the Early Cretaceous Jehol Biota and its paleoecological implications". PLoS ONE. 12 (9): e0185486. doi:10.1371/journal.pone.0185486.
  8. Andres, B.; Myers, T. S. (2013). "Lone Star Pterosaurs". Earth and Environmental Science Transactions of the Royal Society of Edinburgh: 1. doi:10.1017/S1755691013000303.


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