Titanosauria
Diverse sauropods that survived until the end-Cretaceous extinction.
Titanosaurs, also called titanosaurians, were a varied group of sauropod dinosaurs found on every continent. They were the final long-necked sauropods to survive, with members still alive when the Cretaceous extinction event struck. Among them were some of the largest land animals ever, like *Patagotitan* (roughly 37 meters long and 69 tonnes), and the similarly massive *Argentinosaurus* and *Puertasaurus* from the same region.
The name comes from the Titans of Greek myth, via the type genus *Titanosaurus* (now considered a dubious name). Titanosaurs, along with brachiosaurids and their relatives, form the larger group Titanosauriformes. For a long time, titanosaurs were poorly understood, and the relationships between different species remain unclear.
**Fossil record**
Because titanosaurs lived nearly worldwide during the Cretaceous, their fossils have turned up on every continent, including Antarctica. Yet they have the most incomplete fossil record of any major sauropod group. No complete skeleton exists, and many species are known only from a few bones. Titanosaur skulls are especially rare. While fragmentary skull pieces exist for several genera, only four have nearly complete skulls described: *Nemegtosaurus*, *Rapetosaurus*, *Sarmientosaurus*, and *Tapuiasaurus*. As with most sauropods, few specimens preserve complete necks with all vertebrae in order. Only three complete titanosaur necks are known: the holotype of *Futalognkosaurus* and two undescribed Argentine finds. A fourth, from an unidentified Brazilian titanosaur, is nearly complete, missing only the atlas (the tiny vertebra connecting skull and neck). Just five specimens have complete, articulated hind feet. This incompleteness is especially true for giant titanosaurs, which are usually known from scattered, broken bones.
Titanosaurs are among the few dinosaurs with known fossil eggs. The site of Auca Mahuevo preserves a titanosaur nesting ground. Some eggs contain fossil embryos, which even preserve skin. These embryos are among the few titanosaur specimens with complete skulls.
**Description**
Titanosauria shows the widest range of body sizes of any sauropod group, including both the largest and some of the smallest sauropods. *Patagotitan* weighed about 69 tonnes, while *Magyarosaurus* was roughly 900 kilograms.
Quick Facts
- Taxon
- Titanosauria
Facts from the source article.
Lore & Background
Titanosaurs had small heads, wide nostrils, and crests formed by nasal bones. Their necks were of average length for sauropods, and their tails were whip-like. The pectoral area was much wider than in other sauropods, giving them a uniquely 'wide-legged' stance. Titanosaurs retained reduced digits (usually phalanges on some toes) and did not completely lose digits; their feet were not entirely stump-like without any digits. Their vertebrae were opisthocoelous or procoelous with internal cavities (camellate or pneumatic), not solid, and their spinal column was relatively flexible. Many titanosaurs were armored with a small mosaic of scales, and some had osteoderms.
Reader's Guide
Titanosaurs are significant as the last surviving group of long-necked sauropods, persisting until the end-Cretaceous extinction event. Their fossils have been found on every continent, including Antarctica, demonstrating a near-global distribution during the Cretaceous. Despite their importance, they have the least complete fossil record of any major sauropodomorph group, with no complete skeletons known and many species represented only by fragmentary remains. This incompleteness is especially pronounced for giant titanosaurs. The group includes both the largest land animals ever known, such as Patagotitan, and some of the smallest sauropods, like Magyarosaurus, showing an extreme range of body size. Titanosaurs are one of the few dinosaur groups for which fossil eggs are known, with a nesting ground at Auca Mahuevo preserving eggs containing embryos with fossil skin. Their unique wide-legged stance, solid vertebrae, and flexible spinal column distinguish them from other sauropods. The presence of osteoderms in some titanosaurs adds to their distinctive anatomy. The relationships among titanosaur species remain poorly understood, and the group's name alludes to the mythological Titans of ancient Greek mythology.
Did You Know?
- Titanosaurs are one of the few dinosaur groups for which fossil eggs are known; a nesting ground at Auca Mahuevo preserves eggs with embryos and fossil skin.
- Some titanosaurs, such as Magyarosaurus, were island dwarfs, while others like Patagotitan were among the largest land animals ever.
More in Cretaceous dinosaurs 1-24
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