Temporal range: Early Cretaceous
An artist's illustration of Sauroposeidon proteles
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Superorder: Dinosauria
Order: Saurischia
Suborder: Sauropodomorpha
Family: Titanosauriformes
Subfamily: Somphospondyli
Genus: Sauroposeidon
Wedel, Cifelli & Sanders, 2000

Sauroposeidon proteles is a genus of brachiosaurid sauropod dinosaur. It is only known from four neck vertebrae that were found in South-Eastern Oklahoma. The fossils were discovered in an early Cretaceous period rock layer, a time-span in which sauropods were thought to have greatly decreased in both size and number, making Sauroposeidon the one of the last great sauropod of the North American continent. When the fossils were discovered in 1993 in Atoka County in Oklahoma, their size and time of origin caused them to be missclassified as petrified tree trunks, until 1999, when a further study revealed the truth. When this was realised, it caused a media frenzy.

Sauroposeidon vertebrae.

Paleoecological analysis shows that this Sauroposeidon lived on the shore of the Gulf of Mexico, which at the time streched into oklahoma, near the mouth of a great river. Like all other Brachiosaurids, it was a quadropedal herbivore with front legs longer that the rear legs, a build similar to a modern giraffe. Extrapolations based on its more completely known relative Brachiosaurus indicate that the head of Sauroposeidon could reach 18 meters in height with its neck extended, making it the tallest known dinosaur. With an estimated length of up to 34 meters (112 feet) and a mass of 50–60 tons (55–66 short tons), it also ranks among the longest and heaviest.

Name Origin

800px-Sauroposeidon Scale Diagram Steveoc86.svg.png

The name comes from Greek sauros, meaning lizard, and the Greek sea god, Poseidon, who was also the god of earthquakes, often being called Ennosigaios, "The Earth Shaker". This is a reference to the notion that this sauropod was so massive, when it walked the earth shaked.

The species name, protelis, also comes from Ancient Greek, meaning "Perfect before the End", refering to Sauroposeidon's status as the last great sauropod.


The press release of the discovery in 1999 immediatly gathered international media attention, which led to many innacurate reports of "the largest dinosaur ever!" While it is true that Sauroposeidon is probably the tallest known dinosaur (However, this animal may not be as closely related to Brachiosaurus as previously thought, so these estimates may be inaccurate.), it is neither the longest or most massive. Argentinosaurus is a better candidate for this title (presuming we ignore the controversial Amphicoelias, which most scientists do), though weak fossil remains for both Sauroposeidon and Argentinosaurus make exact ranking impossible.

The initial find of Sauroposeidon consisted of only four, elongated, mid-cervical vertebrae, numbers 5-8.The largest vertibrae measured an astonishing 1.4 meters, or 4.6 feet, making it the largest sauropod vertibrae ever. Examination of the bones revealed that they were honeycombed with tiny air pockets to reduce weight, to make lifting the neck much easier. The cervical ribs were remakably long as well, with the longest cervical rib of any sauropod on vertebra 6, measuring 3.42 meters (11.2 feet).


Estimates of Sauroposeidon's size are based on a comparison between the four Sauroposeidon vertebrae and the vertebrae of the HM SII specimen of Giraffatitan brancai, located in the Humboldt Museum in Berlin. The HM SII is the most complete brachiosaur known, though since it is composed of pieces from different individuals its proportions may not be totally accurate. Comparisons to the other brachiosaurid relatives of Sauroposeidon are difficult due to limited remains.

Sauroposeidon's neck legnth is estimated at 11.25–12 m. (37–39 feet.), compared to the 9 meters (30 feet.) neck of Giraffatitan. Sauroposeidon could likely raise its neck 17 meters (56 feet.) off the ground, the equivalent of a six story building. In comparison, Giraffatitan could probably raise it's head a modest 13.5 meters (44 feet.) into the air. Sauroposeidon's height at the shoulder is estimated to be 6–7 meters (20–23 feet.), and it's body legnth ranged from 28 m. (92 feet.), to 34 meters (110 feet.), making it one of the longest sauropods, and might be among the tallest.

Sauroposeidon's mass is estimated at 50-60 t. (55-66 short tons). While the vertibrae are 25-33% longer than Giraffatitan's they are only 10-15% larger in diameter, making the neck very gracile in comparison to most other Brachiosaurids. This means the body was most often slimmer in comparison to the neck legnth, making it weight noticably less than a Giraffatitan of the same size.

Clash of the Dinosaurs Sauroposeidon


Sauroposeidon was likely the last giant sauropod, which lived in an age of sub-conpact Titanosaurs. Sauropods, which included the largest land animals ever, were a succesful and wide-spread group They first appeared in the Late episode to be preyed on by Acrocanthosaurus (a carnosaur a bit smaller than a T. rex) and large packs of Deinonychus.

Many sauropods were herding animals, and Sauroposeidon was no different.

A giant brachiosaurid similar to Sauroposeidon was described in 2004, by Darren Naish and colleagues, and is from the Early Cretaceous period of England. Known only from two neck vertebrae, it was apparently similar in some details to Sauroposeidon and perhaps similar in size. Its discovery highlights the similarity seen between Early Cretaceous North American and European dinosaurs.

In the Media

  • It is the state dinosaur of Texas.
  • Sauroposeidon made an appearance in every episode of the famous documentary Clash of the Dinosaurs, where a herd of them was shown to walk great distances to eat and lay their eggs. In other episodes it talked about how they wern't very smart, like all sauropods, and how they didn't even raise their own young. It also showed how the young ones lived in the forest until they grew to be 1/3 their adult size, and one of them was attacked and killed by a pack of Deinonychus. The Sauroposeidon model was used for Alamosaurus in Last Day of the Dinosaurs (even though Alamosaurus had different proportions than Sauroposeidon).
  • It appears in the show Monsters Resurrected under its' junior synonym, Paluxysaurus. It was shown to be the prime food source of Acrocanthosaurus.
  • It appears in Prehistoric: Dallas, also under the name Paluxysaurus and also as the prey for Acrocathosaurus. (Chase based on a actual footprint fossil find)
  • It appears in Dinosaur Train, with a light violet color and blue patterns on its back.
  • Sauroposiedon was shown in a database scene with Acrocanthosaurus in Planet Dinosaur, representing their close and life-saving relationship, Acrocanthosaurus depending on Sauroposeidon for food.