Titanosaurus (meaning ‘titanic lizard’ – named after the mythological ‘Titans’, deities of Ancient Greece) is a dubious genus of sauropod dinosaurs, first described by Lydekker in 1877. It is known from the Maastrichtian (Upper Cretaceous) Lameta Formation of India.
Titanosaurus is estimated to have grown up to 9–12 metres (30–40 ft) long and up to approximately 13 tons in weight. Wilson and Upchurch (2003) treated Titanosaurus as a nomen dubium (“dubious name”) because they noted that the original Titanosaurus specimens cannot be distinguished from those of related animals.
Titanosaurus is the signature member of the family of dinosaurs known as titanosaurs, which were the last sauropods to roam the earth before the K/T Extinction 65 million years ago.
What’s odd is that, although paleontologists have discovered plenty of titanosaurs–the remains of these giant beasts have been dug up all over the globe–they’re not so sure about the status of Titanosaurus: this dinosaur is known from very limited fossil remains, and to date, no one has located its kull. This seems to be a trend in the dinosaur world; for example, hadrosaurs (duck-billed dinosaurs) are named after the extremely obscure Hadrosaurus, and the aquatic reptiles known as pliosaurs are named after the equally murky Pliosaurus.
Titanosaurus was discovered very early in dinosaur history, identified in 1877 by paleontologist Richard Lydekker on the basis of scattered bones unearthed in India (not normally a hotbed of fossil discovery). Over the next few decades, Titanosaurus became a “wastebasket taxon,” meaning that any dinosaur that even remotely resembled it wound up being assigned as a separate species.
Today, all but one of these species have either been downgraded or promoted to genus status: for example, T. colberti is now known as Isisaurus, T. australis as Neuquensaurus, and T. dacus as Magyarosaurus. (The one remaining valid species of Titanosaurus, which still remains on very shaky ground, is T. indicus.)
Lately, titanosaurs (but not Titanosaurus) have been generating headlines, as bigger and bigger specimens have been discovered in South America. The largest dinosaur yet known is a South American titanosaur, Argentinosaurus, but the recent announcement of the evocatively named Dreadnoughtus may imperil its place in the record books. There are also a few as-yet-unidentified titanosaur specimens that may have been even bigger, but we can only know for sure pending further study by experts.
As the type genus of Titanosauria, Titanosaurus at times became a wastebasket taxon for a number of titanosaurs, including those not just from India but also southern Europe, Laos, and South America. Only two among these, however, are currently considered species of Titanosaurus: T. indicus and T. blandfordi, both of which are considered nomina dubia.
Other species formerly referred to this genus include:
- “Titanosaurus” rahioliensis – Described based on teeth, this species is now considered an indeterminate neosauropod.
- “Titanosaurus” colberti – This species was the most well-known species of Titanosaurus, but has been moved into its own genus, Isisaurus.
- “Titanosaurus” australis – Known from relatively complete remains, but has been renamed Neuquensaurus.
- “Titanosaurus” nanus – A small species found to be non diagnostic, and hence a nomen dubium.
- “Titanosaurus” robustus – Now referred to Neuquensaurus.
- “Titanosaurus” madagascariensis – nomen dubium; UCB 92305 apparently related to Vahiny, while UCM 92829 has been re-assigned to Rapetosaurus.
- “Titanosaurus” falloti – This large species, native to Laos, has disputed affinities. It has been considered synonymous with Tangvayosaurus and Huabeisaurus, but the remains are too fragmentary to be sure.
- “Titanosaurus” valdensis – Referred to a new genus, Iuticosaurus, but still considered a nomen dubium.
- “Titanosaurus” lydekkeri – Also referred to Iuticosaurus, but its relation to I. valdensis is uncertain.
- “Titanosaurus” dacus – A dwarf titanosaur; now moved to the genus Magyarosaurus.