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Chinese sauropod info



As I promised, here are the Upchurch refs:

Upchurch, P. 1995. The evolutionary history of sauropod dinosaurs. Phil. Trans. R. Soc. Lond. B, 349: 365-390.

Upchurch, P. 1998. The phylogenetic relationships of sauropod dinosaurs. Zoological Journal of the Linnean Society, 124: 43-103.

Upchurch, P. 1999. The phylogenetic relationships of the Nemegtosauridae (Saurischia, Saruopoda). Journal of Vertebrate Paleontology, 19(1): 106-125.

Upchurch propsed a Eusauropoda which comprises all sauropods above Vulcanodontidae (Barapasaurus, Ohmdenosaurus, Vulcanodon, Zizhongosaurus) and incorporates both the Euhelopodidae and Cetiosauridae as outgroups to the Neosauropoda, which includes all other sauropods.

According to Upchurch, his Euhelopodidae contains the following genera: Datousaurus, Euhelopus, Mamenchisaurus, Omeisaurus, Shunosaurus. Upchurch considers the tail club in Shunosaurus to be an autoapomorphy rather than a synapomorphy of the Euhelopodidae.

Here are the seven synapomorphies Upchurch has used to justify Euhelopodid monophyly:

1. Caudal end of the prefrontal is triangular in dorsal view (convergently acquired in Diplodocidae); 2. 13 cervical vertebrae (convergently acquired in Brachiosaurus and Diplodocidae); 3. Laterally compressed cranial cervical vertebrae; 4. Centroparapophyseal lamina on middle and caudal dorsal neural arches (absent in some euhelopodids; convergently acquired in the Neosauropoda); 5. cranial process on middle and distal chevrons (convergently acquired in the dicraeosaurid-diplodocid clade); 6. Ventral midline slit on middle and distal chevrons (convergently acquired in the dicraeosaurid-diplodocid clade); 7. Prominent parasagittally oriented ridge on the dorsal surface of the sternal plate.

I encourage anyone interested to look up these articles and read them for a somewhat different and interesting view on sauropod evolution.

Matt Bonnan

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