Rhamphorhynchus the BMM specimen and Qinglongopterus

Rhamphorhynchus sp. Late Jurassic ~155 mya, unnumbered BMM specimen, was considered a juvenile Rhamphorhynchus due to its small size, short wings, short tail and short rostrum. Here the BMM specimen was derived from a sister to Rhamphorhynchus intermedius n28 and it phylogenetically preceded Rhamphorhynchus longicaudus n10.

Distinct from R. intermedius, the rostrum of the BMM specimen was dramatically shortened and the antorbital fenestra was enlarged. The teeth were relatively larger, but fewer.

The cervicals, dorsals and caudals were shorter relative to the wing elements. The tail vertebrae were not elongated nor were they provided with extended zygopophyses and chevrons.

The scapula and coracoid were relatively more robust, as were al the wing elements.

The pelvis was shallower. The metatarsals were shorter. Note the tiny bones of the toes were completely ossified.

We know that this taxon was an adult or greatly resembled the adult due to the examples of other clade members, Huehuecuetzpalli (Reynoso 1998), the JZMP embryo (Ji et al. 2004), the Pterodaustro embryo, (Chiappe et al. 2004) and the Pteranodon ingens juvenile. This upsets a long-standing tradition (Wellnhofer 1970, Bennett 1993a, b, 1995, 1996a, 2001a,b, 2006, 2007, Wang and Zhou 2004) that pterosaurs mature allometrically like birds, crocs and mammals.

See R. longiceps for size comparisons. See Campylognathoides C4 for a local family tree.

Campylognathoides-Rhamphorhynchus transition

Three sister taxa displaying a phylogenetic size reduction at the transition from Campylognathoides to Rhamphorhynchus. At left, Campylognathoides liasicus. Middle, Rhamphorhynchus intermedius. Lower right, the BMM specimen of Rhamphorhynchus. All were adults.

Qinglongopterus guoi Lü et al. (2012) erected a new genus and species for a new rhamphorhynchid from the Tiaojishan Formation of China (Mid/Late Jurassic). They reported, "Qinglongopterus is strikingly similar to Rhamphorhynchus and more closely related to this taxon than to any other rhamphorhynchine."

Lü et al. (2012) considered the Qinglongopterus specimen immature due to lack of fusion in the scapula + coracoid, carpals, extensor tendon epiphysis, pubis and ischium, etc. However they noticed, "external bone surfaces appear to be fairly well ossified and do not exhibit the coarse, fibrous texture evident in the rostrum and limb bones of embryos."

Lü et al. (2012) considered their find an archosaur because they used Euparkeria for an outgroup taxon. While noting similarities to Rhamphorhynchus and considering the specimen immature, oddly Lü et al. (2012) did not test their find against any so-called "immature" Rhamphorhynchus specimens. Their analysis of 37 taxa recovered 550 trees and nested Qinglongopterus with R. muensteri.

Qinglongopterus was inserted into the matrix of the large pterosaur study, which included eleven Rhamphorhynchus specimens of all sizes. The completely resolved tree nested Qinglongopterus as a successor to the BMM Rhamphorhynchus and a predecessor to Wellnhofer's (1975) No. 10, two Rhamphorhynchus specimens generally and traditionally considered juveniles.

Distinct from sister taxa in the present study manual 2.2 was longer than m2.1. Manual 3.3 was not as long as m3.1 + m3.2. The pes was relatively smaller than the tibia. Pedal 2.1 was longer than p3.1. The sternal complex was wider than long.

Qinglongopterus is featured in

Wang X-L and Zhou Z 2004. Palaeontology: pterosaur embryo from the Early Cretaceous. Nature 429: 623.

Bennett SC 1993a. The ontogeny of Pteranodon and other pterosaurs. Paleobiology 19, 92–106.

Bennett SC 1993b. Year classes of pterosaurs from the Solnhofen limestone of southern Germany. Journal of Vertebrate Paleontology. 13, 26A.

Bennett SC 1995. A statistical study of Rhamphorhynchus from the Solnhofen limestone of Germany: year classes of a single large species. Journal of Paleontology 69, 569–580.

Bennett SC 1996a. Year-classes of pterosaurs from the Solnhofen limestones of Germany: taxonomic and systematic implications. Journal of Vertebrate Paleontology 16:432–444.

Bennett, SC 1996b. The phylogenetic position of the Pterosauria within the Archosauromorpha. Zoological Journal of the Linnean Society 118:261–309.

Bennett SC 2001a, b. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Part I. General description of osteology. Palaeontographica, Abteilung A, 260:1–112. Part II. Functional morphology. Palaeontographica, Abteilung A, 260:113–153.

Bennett SC 2006. Juvenile specimens of the pterosaur Germanodactylus cristatus, with a review of the genus. Journal of Vertebrate Paleontology 26:872–878.

Bennett SC 2007. A review of the pterosaur Ctenochasma: taxonomy and ontogeny. Neues Jahrbuch fur Geologie und Paläontologie, Abhandlungen 245:23–31.

Chinsamy A, Codorniú L and Chiappe LM 2008. Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guinazui. Biology Letters, 4: 282-285.

Chiappe LM, Codorniú L, Grellet-Tinner G and Rivarola D. 2004. Argentinian unhatched pterosaur fossil. Nature, 432: 571.

Codorniú L and Chiappe LM 2004. Early juvenile pterosaurs (Pterodactyloidea: Pterodaustro guinazui) from the Lower Cretaceous of central Argentina. Canadian Journal of Earth Science 41, 9–18. (doi:10.1139/e03-080)

Deeming C and Unwin DM 2007. Eggshell structure and its implications for pterosaur reproductive biology and physiology. Flugsaurier, the Wellnhofer pterosaur meeting, Munich, 12.

Grellet-Tinner G, Wroe S, Thompson SB and Ji Q 2007. A note on pterosaur nesting behavior. Historical Biology 19:273–277.

Ji Q, Ji S-A, Cheng Y-N, You HL, Lü J-C, Liu Y-Q and Yuan CX 2004. Pterosaur egg with leathery shell. Nature 432:572.

Lü J, Unwin DM, Zhao B, Gao C and Shen C 2012. A new rhamphorhynchid (Pterosauria: Rhamphorhynchidae) from the Middle/Upper Jurassic of Qinglong, Hebei Province, China. Zootaxa 3158:1-19. online first page

Reynoso V-H 1998. Huehuecuetzpalli mixtecus gen. et sp. nov: a basal squamate (Reptilia) from the Early Cretaceous of Tepexi de Rodríguez, Central México. Philosophical Transactions of the Royal Society, London B 353:477-500.

Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

wiki/Qinglongopterus

wiki/Rhamphorhynchus

Campylognathoididae

Campylognathoides C4

Campylognathoides Cz

Campylognathoides C5

Nesodactylus

Campylognathoides C3

Rhamphorhynchus

Rhamphorhynchus n28

Bellubrunnus

Rhamphorhynchus n10