They, or some of them, may have been viviparous like the Ichthyosaurus.] [Footnote 13: European palaeontologists, especially Huxley and Seeley in England, had also recognized their true relationships, and Seeley's term Cetiosauria has precedence over Sauropoda, although the latter is in common use.] [Footnote 14: It is of interest to observe that in this group of Sauropoda, the Brachiosauridae, the neural spines of the vertebrae are much simpler and narrower than in the Brontosaurus and Diplodocus.

The attachments were thus less extensive for the muscles of the back, indicating that these muscles were less powerful.

This difference is correlated by Professor Williston with the longer fore limbs of the Brachiosaurus, as signifying that the animal was less able, as indeed he had less need, to rise up upon the hind limbs, in comparison with Diplodocus or Brontosaurus in which the fore limbs were relatively short.].