Tuesday, February 22, 2011

"Megacervixosaurus" and Kunmingosaurus - Zhao's nomina nuda part 7

Figure I have these things written, might as well post them. Today we finish off the sauropods. Remember the references not listed are in the first Zhao nomen nudum post.

"Megacervixosaurus" Zhao, 1983
"Megacervixosaurus tibetensis" Zhao, 1986
Etymology- The genus name refers to a large neck, while the species name refers to Tibet where the remains were found.

Late Cretaceous
Zonggu Formation, Zonggu, Markam County, Tibet, China
Material-
specimen including cervical vertebrae
Comments
- Zhao (pers. comm. in Molnar, 2011) noted similarity of its posterior cervicals to Austrosaurus.
Relationships- Stated by Zhao (1983) to be a homalosauropodoid, in which he includes peg-toothed taxa like diplodocoids and titanosaurs.  Lambert (1990), Olshevsky (1991) and provisionally Glut (1997) listed it as a diplodocid.   Olshevsky (online, 1999) also suggested it may be mamenchisaurid, perhaps based on the name, though Zhao did place Mamenchisaurus in Homalosauropodoidea too .  Weishampel et al. (2004) questioningly listed it as a lithostrotian.
As no morphological data has been released on "Megacervixosaurus", its relationships must necessarily remain tentative.  The absence of Cretaceous or Asian diplodocids renders that identification suspect, while mamenchisaurids are also unknown from the Cretaceous.  Indeed, the only Late Cretaceous sauropods are rebbachisaurids and titanosaurs, and only the latter are known from East Asia.  "Megacervixosaurus" is here considered a probable titanosaur.

References
- Yang, 1986. The Cretaceous System. in Yang, Cheng and Wang (eds.). The Geology of China. Clarendon Press. 153-167.
Zhao,  1986. [unknown title] in Hao, Su, Yu and Li (eds.). The Cretaceous System of China. Stratigraphy of China. 12, 67-73.
Molnar, 2011. New morphological information about Cretaceous sauropod dinosaurs from
the Eromanga Basin, Queensland, Australia. Alcheringa: An Australasian Journal of Palaeontology. DOI: 10.1080/03115518.2011.533978
Kunmingosaurus Zhao vide Dong, 1992
K. wudingensis
Zhao vide Dong, 1992
= "Kunmingosaurus wudingi" Zhao, 1985
= "Kunmingosaurus utingensjs" Zhao, 1985
= "Kunmingosaurus utingi" Zhen, Li and Rao, 1986
= "Kunmingosaurus utingensis" Chure and McIntosh, 1989
= "Kunmingosaurus wudingensis" anonymous, 1990 vide Olshevsky, 1991
= Kunmingosaurus wusdingensis Weishampel, Barrett, Coria, Le Loeuff, Xu, Zhao, Sahni, Gomani and Noto, 2004
Etymology- Kunming is the capital city of Yunnan, while Wuding is the county and basin the specimen was found in.
Hettangian, Early Jurassic
Zhangjiawa Member of the Lufeng Formation, Hoshaofang, Wuding County, Yunnan, China
Holotype
- (IVPP coll.) (~11 m) incomplete skeleton including dorsal vertebrae, eight proximal caudal vertebrae, four chevrons, ilium, pubis, femur (~847 mm), tibia, fibula, astragalus, metatarsal I, phalanx I-1, pedal ungual I, metatarsal II, phalanx II-1, pedal ungual II, metatarsal III, phalanx III-1, phalanx III-2, pedal ungual III, metatarsal IV, phalanx IV-1, metatarsal V, phalanx V-1
....(BNHM,PZGR 74) dentary
....(BNHM,PZGR 75) dentary
Referred- ?(FMNH CUP 2042) maxilla (Barrett, 1999)
?(IVPP coll.) tooth (Upchurch and Barrett, 2000)
Kunmingosaurus wudingensis holotype dentaries BNHM,PZGR 74 and 74 in medial (top) and lateral (bottom) views, with four teeth in labial and lingual views. After Young (1966). 
Kunmingosaurus wudingensis holotype posterior skeleton (after Zhao, 1985).

Comments- The species name is spelled "wudingi" in the text, and "utingensjs" in the figure caption, which as noted by Chure and McIntosh (1989) are probably unintentional variants, and the latter no doubt a mispelling of "utingensis". 
The skeleton was discovered by Su in 1954, but the dentaries were only discovered later in 1960 and described and illustrated by Young (1966) as specimens of Lufengosaurus magnus.  Dong (1992) referred them to the same individual as the postcrania since they came from the same quarry.  While Dong (and later Olshevsky, 2000) was incorrect in stating  Zhao described the taxon in 1985, his own book contains a diagnosis, type and illustration so would seem to validate the nomenclature (contra Barrett, 1999).  Indeed, Upchurch et al. (2004) attribute the name to Dong, 1992.  A photo of part of the mounted skeleton is in Zhao (1985), contra Barrett (1999).  Dong et al. (1990) published a photograph of the entire skeleton, and several are available online as well.    
Li et al. (2010) note Kunmingosaurus lacks dorsal pleurocoels and has a poorly developed fourth trochanter.
Simmons (1965) described a maxilla (FMNH CUP 2042) from Ta Ti in the same beds as Yunnanosaurus robustus, which is similar to Kunmingosaurus in having a sauropodan lateral plate and serrated, spatulate teeth with a lingual ridge.  Barrett (1999) redescribed it as a sauropod maxilla, though he did not refer it to any genus.  Upchurch and Barrett (2000) described a referred tooth.

Relationships
- Stated by Zhao (1985) to be a primitive sauropod.  Chure and McIntosh (1989) and Lambert (1990) listed it as a cetiosaurid, while Olshevsky (1991) listed it provisionally as a barapasaurid and Dong (1992) as a shunosaurine camarasaurid. Upchurch and Barrett (2000) discussed it as a 'vulcanodontid', which was a grade of basal sauropods in their scheme, and described a referred tooth.  Upchurch (1995) noted there was no published evidence suggesting it was a vulcanodontid, however.  He later (1998) noted that Kunmingosaurus' teeth were more plesiomorphic than Barapasaurus, Shunosaurus, Patagosaurus and other taxa in having only a shallow lingual concavity and being quite labiolingually compressed.  Barrett (1999) considered the dentaries to be sauropod based on the dorsoventrally expanded symphysis and lateral plate.  Fang et al. (2006) list it as a camarasaurid. 
When entered into a modified version of Wilson's (2002) analysis, Kunmingosaurus emerges more derived than Chinshakiangosaurus, Antetonitrus, Lessemsaurus and Blikanasaurus but less than  Shunosaurus and eusauropods (so is not a cetiosaurid, barapasaurid, shunosaurid or camarasaurid).  It is thus related to taxa such as Gongxianosaurus, Kotasaurus, Spinophorosaurus, Tazoudasaurus and Vulcanodon, so may be considered vulcanodont-grade.  Note the results agree with Upchurch's (1998) statements, though his dental characters were not used by Wilson.  Specifically, Kunmingosaurus is more derived than Chinshakiangosaurus based on the D-shaped teeth and reduced fourth trochanter, but less derived than Shunosaurus based on no crown-to-crown occlusion, straight dorsal ilial margin and unreduced pedal phalanges.

References
- Simmons, 1965. The non-therapsid reptiles of the Lufeng Basin, Yunnan, China. Fieldiana, Geology. 15, 1-93.
Young, 1966. On a new locality of the Lufengosaurus of Yunnan. Vertebrata PalAsiatica. 10(1), 64-67.
Zhen, Li and Rao, 1986. Dinosaur footprints of Jinnin, Yunnan. Memoirs of the Beijing Natural History Museum.  33, 19pp.
Dong, Hasegawa and Azuma, 1990. The Age of Dinosaurs in Japan and China. Fukui, Japan: Fukui Prefectural Museum. 65 pp.
Dong, 1992. Dinosaurian Faunas of China. China Ocean Press (Beijing). 192 pp.
Upchurch, 1995. The evolutionary history of sauropod dinosaurs. Philosophical Transactions of the Royal Society of London B. 349, 365-390.
Upchurch, 1998. The phylogenetic relationships of sauropod dinosaurs. Zoological Journal of the Linnean Society. 124, 43-103.
Barrett, 1999. A sauropod dinosaur from the Lower Lufeng Formation (Lower Jurassic) of Yunnan Province, People's Republic of China. Journal of Vertebrate Paleontology. 19(4), 785-787.
Martin-Rolland, 1999. Les sauropodes chinois [The Chinese sauropods]. Revue Paléobiologie, Genève. 18(1), 287-315.
Olshevsky, 2000. An Annotated Checklist of Dinosaur Species by Continent. Mesozoic Meanderings. 3, 157 pp.
Upchurch and Barrett, 2000. The evolution of sauropod feeding mechanisms. in Sues (ed.). Evolution of Herbivory in Terrestrial Vertebrates: Perspectives from the Fossil Record. Cambridge Press. 79-123.
Upchurch, Barrett and Dodson, 2004. Sauropoda. in Weishampel, Dodson and Osmolska (eds.). The Dinosauria: Second Edition.  University of California Press. 259-322.
Li, Yang, Liu and Wang, 2010. A new sauropod from the Lower Jurassic of Huili, Sichuan, China. Vertebrata PalAsiatica. 48(3),185-202.

2 comments:

  1. Hmm... someone left a comment, bvut it didn't appear here (only in email). In case they didn't intend to delate it, Glut (1997) mentioning pelvic and other characters in his "Megacervixosaurus" entry is based on Zhao's (1983) diagnosis for Homalosauropodoidea, so do not indicate characters definitely known in "Megacervixosaurus".

    The 11 meter length for Kunmingosaurus is based on lengths of the mounted skeleton from sites offering casts. Who knows how accurate it is, since we don't know how much of the vertebral column is preserved.

    There are certainly characters diagnosing sauropods, but which characters depends on the definition used for Sauropoda. The latter has been defined as everything closer to traditional sauropods than to Plateosaurus, as Vulcanodon plus other sauropods, and a few things in between as well.

    ReplyDelete
  2. Thanks for reply, the message I sent, Rexisto.

    Not because instead of being on the blog appeared in your mail, but never mind.

    Reconstructions of Chinese sauropods usually based on Mamenchisaurus and therefore applied this model to Kunmingosaurus but apparently if this genre is less advanced than Shunosaurus, it is obvious that there is an error.

    There are several sauropods in China or other countries, which are reconstructed based on a very poor material and not be described in a professional manner: Otogosaurus, Nurosaurus, or the same Kunmingosaurus Mohabosaurus for example.

    A curious fact is that he had previously Monolophosaurus unofficially as Kunmingsaurus.

    ReplyDelete