DIPLODOCIMORPHA
CLASSIFICATION
Animalia: Vertebrata: Tetrapoda: Sauropsida: Archosauromorpha:
Ornithodira: Dinosauria: Sauropodomorpha: Sauropoda
CLADOGRAM:
--Diplodocimorpha "Diplodocus forms" == {Diplodocus > Saltasaurus}
| INCERTAE SEDIS:
| indeterminate material -- Cenomanian? -- Argentina
| ?Hisanohamasaurus
| ?Megacervixosaurus
| ?Mongolosaurus
|--Amphicoelias
|--Losillasaurus
|--Rebbachisauridae
| | INCERTAE SEDIS:
| | unnamed form (dentary) -- Late Cretaceous -- S. America
| | ?Histriasaurus
| |--Nigersaurus
| |--Rayososaurus
| `--Rebbachisaurinae
| |--Limaysaurus
| `--Rebbachisaurus
`--Diplodocoidea == {Diplodocus + Dicraeosaurus}
| INCERTAE SEDIS:
| unnamed form (cervical & dorsal vertebrae) -- Cenomanian -- Niger
|--Dicraeosauridae
| | INCERTAE SEDIS:
| | ?cf. Dicraeosaurus -- Albian to early Cenomanian -- Africa
| |--Amargasaurus
| `--Dicraeosaurus
`---->Diplodocidae
ALTERNATE CLADOGRAM:
--Diplodocimorpha
|--+--Diplodocoidea
| `--Rebbachisauridae
`--+?-Antarctosaurus
`--Nemegtosauridae
|--Nemegtosaurus
`--Quaesitosaurus
ESSAY
| Members of this group had long, whip-like tails (possibly used for defense), peg-like teeth, and high vertebral spines. The extremely long spines of some diplodocimorphs, such as Amargasaurus and Rebbachisaurus, may have formed large dorsal sails, like those of the theropod Spinosaurus and the ornithopod Ouranosaurus. Some of these animals, like the dicraeosaurids, made it into the Cretaceous, but not to the end of the Mesozoic Era. T HE E LUSIVE GIANT:There is a possible diplodocimorph named Amphicoelias fragillimus, known from a drawing of a crumbling neural arch. Based on comparison to other diplodocimorphs, it would have been about 50m long and weighed about 120-150 tonnes, making it by far the largest land creature of all time! Unfortunately, the actual specimen has been lost, presumably disintegrated, for a long time (if it ever, indeed, existed). |
