Introduction to Titanosauria
Lydekker (1893:3) and Depéret (1899) described species of Titanosaurus from South America and Madagascar, recognizing a “remarkable community of type which undoubtedly exists between the faunas of southern continents of the world”. Titanosaurus and the Family Titanosauridae (Lydekker, 1893) soon swelled to include numerous constituent taxa, despite often tenuous associations and limited morphological overlap. Fifty years later, Charles Gilmore (1946) recognized that the family represented a wastebasket taxon (see below). “Titanosaurus indicus”, “Titanosauridae” and coordinated rank-taxa are now considered invalid (Wilson & Upchurch 2003), but the unranked taxon Titanosauria remains valid.
  The holotypic caudal vertebrae can no longer be located at the British Museum of Natural History or the Geological Survey of India; as a consequence, the morphology of these bones is only available from published illustrations (photographs are as yet unknown). Falconer’s illustration of the bones (at right) indicates that the caudal vertebra has ball-and-socket articulations ‘procoelous’, a condition that was not present in other dinosaurs at the time of discovery. Like other early dinosaur discoveries (e.g., Iguanodon anglicus, Megalosaurus bucklandii, Cetiosaurus medius), T. indicus was founded on fragmentary remains with few diagnostic characters. Over time, many new and often fragmentary specimens were referred to the genus or named as closely related genera, based on the presence of procoelous caudal vertebrae.