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Sauroposeidon

2007 Schools Wikipedia Selection. Related subjects: Dinosaurs

   iSauroposeidon

                       Fossil range: Early Cretaceous

                  Conservation status

   Extinct (fossil)
               Scientific classification

   Kingdom:    Animalia
   Phylum:     Chordata
   Class:      Sauropsida
   Superorder: Dinosauria
   Order:      Saurischia
   Suborder:   Sauropodomorpha
   Infraorder: Sauropoda
   Family:     Brachiosauridae
   Genus:      Sauroposeidon
               Wedel et al, 2000

                                   Species

   S. proteles

   Sauroposeidon was a sauropod from the Early Cretaceous Period, related
   to the more famous Brachiosaurus. The only specimen to date is
   represented by four neck vertebrae. It was the tallest dinosaur known,
   estimated at 18 m (60 ft).

   Its name is Greek for " lizard- Poseidon". The Greek sea-god Poseidon
   was also known as Ennosigaios or Enisokhthōn = "Earthshaker". The
   reference here is to the ground shaking under its weight as it walked:
   compare Seismosaurus.

Discovery

   The vertebrae were discovered in rural Oklahoma, not far from the Texas
   border, in a claystone outcrop that dates the fossils to about 110
   million years ago ( mya). This falls within the Early Cretaceous
   Period, specificially between the Aptian and Albian epochs.

   The four neck vertebrae were discovered in 1994 at the Antlers
   Formation in Atoka County, Oklahoma by Dr. Richard Cifelli and a team
   from the Oklahoma Museum of Natural History.

   While discovered in 1994, the vertebrae were stored until three years
   later, when Dr. Cifelli gave them to a graduate student, Matt Wedel, to
   analyze as part of a project. Upon their realization of the find's
   significance, they issued a press release in October of 1999, followed
   by official publication of their findings in the Journal of Vertebrate
   Paleontology in March of 2000. The new species was dubbed S. proteles,
   and the holotype is OMNH 53062.

Etymology

   The genus name comes from sauros ( Greek for "lizard"), and Poseidon, a
   sea-god in Greek mythology, who is also associated with earthquakes.
   The species name proteles also comes from the Ancient Greek and means
   "perfect before the end", which refers to Sauroposeidon's status as the
   last and most specialized giant sauropod known in North America, during
   the Early Cretaceous.

Who's the biggest?

          "It's truly astonishing. It's arguably the largest creature ever
          to walk the earth."

                — Richard Cifelli, discoverer of Sauroposeidon

   The press release in 1999 immediately garnered international media
   attention, which led to many (inaccurate) news reports of "the largest
   dinosaur ever!". While it is true that Sauroposeidon is probably the
   tallest known dinosaur, it is neither the longest nor the most massive.
   Supersaurus and Argentinosaurus are better candidates for the title
   "World's Largest Dinosaur", though weak fossil evidence makes an exact
   ranking impossible.

   The Sauroposeidon find was composed of four articulated, mid-cervical
   vertebrae (numbers 5 to 8), with the cervical ribs in place. The
   vertebrae are extremely elongated, with the largest one about 1.2
   meters (4 feet) long, which makes it the longest on record. Examination
   of the bones revealed that they are honeycombed with tiny air cells,
   and are very thin, like the bones of a chicken or an ostrich, making
   the neck lighter and easier to lift.

   Estimates of size are based on a comparison between the four
   Sauroposeidon vertebrae and the vertebrae of the HM SII specimen of
   Brachiosaurus 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.

   The neck length of Sauroposeidon is estimated at 11.25 to 12 meters,
   compared to a neck length of 9 meters (30 ft) for the HM SII
   Brachiosaurus. This is based on the assumption that the rest of the
   neck has the same proportions as Brachiosaurus, which is a reasonably
   good conjecture.

   Sauroposeidon was probably able to raise its head 18 meters (60 ft)
   above the ground, which is as high as a six-story building. The long
   neck and the high brachiosaurid shoulders are what makes it the tallest
   known dinosaur. In some ways, its build is similar to the modern
   giraffe, with a short body and an extremely long neck. In comparison,
   the brachiosaur could probably raise its head 13.5 meters (45 ft) into
   the air, and the previous record holder, Diplodocus, might have been
   able to raise its head 15 m.

   Sauroposeidon's shoulders were probably 7 meters off the ground. Its
   estimated length is just under 30 meters (100 ft).

   The mass of Sauroposeidon is estimated at 50 to 60 metric tonnes (55 to
   65 tons). While the vertebrae of Sauroposeidon are 25–33% longer than
   Brachosaurus's, they are only 10–15% larger in diameter. This means
   that while Sauroposeidon probably has a larger body than Brachiosaurus
   its body is smaller in comparison to the size of its neck, so it did
   not weigh as much as a scaled-up Brachiosaurus. By comparison,
   Brachiosaurus might have weighed 36 to 40 tonnes (40 to 44 tons). This
   estimate of the Brachiosaurus is an average of several different
   methodologies.

   However, Sauroposeidon has a relatively gracile neck compared to
   Brachiosaurus. If the rest of the body turns out to be similarly
   slender, the mass estimate may be too high. This could be similar to
   the way the relatively robust Apatosaurus weighs far more than the
   longer but much slimmer Diplodocus. In addition, it is possible that
   sauropods may have an air sac system, like those in birds, which could
   reduce all sauropod mass estimates by 20% or more.

Environment

          "Sauroposeidon was an unexpected discovery, because it was a
          huge, gas-guzzling barge of an animal in an age of subcompact
          sauropods."

                —Matt Wedel, Sauroposeidon team leader

   Sauroposeidon may be the last of the giant North American sauropods.
   Sauropods, which include the largest terrestrial animals of all time,
   were a very wide ranging and successful group. They first appeared in
   the Early Jurassic and it wasn't long before they spread across the
   world. By the time of the late Jurassic, North America and Africa were
   dominated by the diplodocids and brachiosaurids and, by the end of the
   Late Cretaceous, titanosaurids were widespread. Between these periods,
   in the Early Cretaceous, the fossil record is sparse. Most of the other
   sauropods at the time were dying out and, as a result, few specimens
   have been found in North America from that time and those specimens
   that do exist are often fragmentary or represent juvenile members of
   their species. Most of the surviving sauropods at the time were also
   shrinking in size (to a mere 15 m, or 50 ft, in length, and maybe 10 to
   15 tons or tonnes), which makes the discovery of an extremely
   specialized super-giant like Sauroposeidon very unusual.

   Sauroposeidon lived on the shores of the Gulf of Mexico, which ran
   through Oklahoma at that time, in a vast river delta, similar to the
   Mississippi delta today. There were probably no predators who could
   take down a full-grown Sauroposeidon but juveniles were likely prey to
   Acrocanthosaurus (a carnosaur a little smaller than a T. rex) and to
   'packs' of Deinonychus.

   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.
   Retrieved from " http://en.wikipedia.org/wiki/Sauroposeidon"
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