Gravisauria
 |
| Gravisaurians | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Clade: | †Gravisauria Allain & Aquesbi, 2008 |
| Subgroups[2] | |
Gravisauria is a
Classification
The
cladistic analysis of the dinosaur found by Allain, Tazoudasaurus, as the outcome was that the family Vulcanodontidae. The group includes Tazoudasaurus and Vulcanodon, and the sister taxon Eusauropoda, but also certain species such as Antetonitrus, Gongxianosaurus and Isanosaurus that do not belong in Vulcanodontidae but to an even more basic position occupied in Sauropoda. It made sense to have Sauropoda compared to this, more derived group that included Vulcanodontidae and Eusauropoda in a definition: Gravisauria (heavy lizards), defined as the group formed by the last common ancestor of Tazoudasaurus and Saltasaurus (Bonaparte and Powell, 1980) and all its descendants.[1]
Below is a cladogram found by Nair and Salisbury in 2012 showing the relationships of Gravisauria:[2]
| Gravisauria | |
Synapomorphies
Aquesbi mentioned two synapomorphies, shared derived characteristics of Gravisauria: the
vertebrae are wider side to side than front to rear and possession of asymmetrical condyles femoris at the bottom of the femur. Those were previously not thought to be Eusauropoda synapomorphies but Allian found these properties also on Tazoudasaurus.[1]
Involvement in extinction
Gravisauria split off in the
mass extinction.[1]
References
- Najat Aquesbi, 2008, Les Sites de Dinosaures du Lias du Haut Atlas (Maroc), Problèmes de Phylogénie et de Paleogeographie
