Monday, April 23, 2012

Zhao 1986 Cretaceous dinosaurian nomina nuda first impressions

Thanks to Molnar for sending me Zhao's rare 1986 paper on Chinese Reptilia.  In fact, it's so rare that many references confuse it with his 1985 Jurassic reptile paper from another volume in the series and I've only seen its title listed once (by Olshevsky, 1991).  The full citation is...

Zhao, 1986. The Cretaceous biota of China: Reptilia. in Hao, Su, Yu, Li, Li, Wang, Qi, Guan, Hu, Liu, Yang, Ye, Shou, Zhang, et al.. The Cretaceous System of China. Stratigraphy of China. 12, 67-73, plates XI, XII.

As with Zhao 1985 (download the pdf I made of the translation here), I'm working on having someone who actually knows Chinese translate it for me.  In the meantime, I've used OCR software and Google Translate to try my hand at translating the information about the dinosaurian nomina nuda.  Unfortunately, there's not as much information given about each species here as there was in the 1985 paper.  But here's what we have...

Microvenator? "chagyabi" is mentioned once in the Early Cretaceous coelurosaur section, said to be from Tibet.  So nothing new there.

"Megacervixosaurus tibetensis" is also mentioned once, in the Late Cretaceous sauropod section.  Also said to be from Tibet, so again nothing new.

Tyrannosaurus "lanpingi" actually gets the best treatment, since it's the one dinosaur nomen nudum photographed in the paper.  Note Ye (1975) originally named it "lanpingensis", though Zhao credits "lanpingi" to himself (as Chao; though his name is spelled Zhao for the article itself).  The photo is the basal half of a tooth crown in labial view, and has a FABL of ~32 mm.  Only distal serrations are evident, which are small (8 per 5 mm) and have apically angled blood grooves.  The size and serration density fall within the range of Tyrannosaurus rex, but also Carcharodontosaurus saharicus.  Angled blood grooves are known for tyrannosaurids and Carcharodontosaurus, but also taxa like Fukuiraptor.  Importantly, there seem to be prominent enamel wrinkles along the distal carina.  These are almost never found in tyrannosauroids, but are known in derived carcharodontosaurids, Allosaurus and Fukuiraptor (Brusatte et al., 2007).  As "lanpingensis" is from the Early Cretaceous Jingxing Formation of Yunnan, it's more likely to be a megaraptoran or carcharodontosaurid than an allosaurid or tyrannosaurine.  Both are clades known from large taxa (Chilantaisaurus; Carcharodontosaurus, Giganotosaurus, Mapusaurus) and both are known from Asia (Chilantaisaurus, Fukuiraptor; Shaochilong).  If we knew the basal width, we could tell more, since derived carcharodontosaurids have narrower teeth than Fukuiraptor (Molnar et al., 2009).  Maybe Ye (1975) will tell us, which I should be getting soon as well.  Until then, I recommend placing "lanpingensis" in Avetheropoda indet. if you follow my coelurosaurian megaraptorans, or Carnosauria indet. if you follow Benson.

Basal tooth crown of "Tyrannosaurus" "lanpingensis" (after Zhao, 1986).

Prodeinodon is mentioned with early Cretaceous carnosaurs, but not P? "tibetensis", which I was expecting.  "Monkonosaurus lawulacus" is mentioned in the Early Cretaceous ankylosaur/scolosaur section, but it's been subsequently described by Dong and Maidment, so isn't very interesting.  When I have an official translation, I'll correct any data mistranslated here, and add any further details.

In a completely unrelated note, I found an otherwise unmentioned Mesozoic bird name in O'Connor et al. (2011)- "Dalianornis mengi".  It's used in quotes in their data matrix, and is near certainly an early name for Shenquiornis mengi which was described by O'Connor in her thesis, then officially published by Wang et al. (2010).  Notably, Shenquiornis is used in the cladogram and main article.

References- Ye, 1975. Jurassic system. In Su (ed.). Mesozoic Redbeds of Yunnan. Academia Sinica, Beijing. 11-30.

Zhao, 1985. The Jurassic Reptilia. In Wang, Cheng and Wang (eds.). The Jurassic System of China. Stratigraphy of China. 11, 286-289, 347, plates 10 and 11.

Olshevsky, 1991. A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia. Mesozoic Meanderings. 2, 196 pp.

Brusatte, Benson, Carr, Williamson and Sereno, 2007. The systematic utility of theropod enamel wrinkles. Journal of Vertebrate Paleontology. 27(4), 1052-1056.

Molnar, Obata, Tanimoto and Matsukawa, 2009. A tooth of Fukuiraptor aff. F. kitadaniensis from the Lower Cretaceous Sebayashi Formation, Sanchu Cretaceous, Japan. Bulletin of Tokyo Gakugei University, Division of Natural Sciences. 61, 105-117.

Wang, O'Connor, Zhao, Chiappe, Gao and Cheng, 2010. New species of Enantiornithes (Aves: Ornithothoraces) from the Qiaotau Formation in Northern Hebei, China. Acta Geologica Sinica. 84(2), 247-256.

O'Connor, Chiappe and Bell, 2011. Pre-modern birds: Avian divergences in the Mesozoic. in Dyke and Kaiser (eds.). Living Dinosaurs: The Evolutionary History of Modern Birds. 39-114.

Friday, April 20, 2012

Zhao 1986 coming soon

It's been quiet here lately as I finish the coelurosaur phylogeny.  But those of you who are fans of Microvenator? "chagyabi", "Tyrannosaurus" lanpingensis, Prodeinodon? "tibetensis" and "Megacervixosaurus tibetensis" will have cause to rejoice, since I'll soon have Zhao 1986 in my hands.

Zhao, 1986. The Cretaceous biota of China: Reptilia. in Hao, Su, Yu, Li, Li, Wang, Qi, Guan, Hu, Liu, Yang, Ye, Shou and Zang (eds.). The Cretaceous System of China. Stratigraphy of China. 12, 67-73, plates XI, XII.