Re: Sue,T rex

[Dinogeorge@aol.com]

In a message dated 9/15/99 4:57:33 PM EST, Buckaroobwana@aol.com writes:

<< Can anybody give me some basic info on Argentinosaurus? I'm interested in 
the 
 estimated size of the beast. Thanks to whoever answers this message. >>

Here's the unedited and incomplete text from my forthcoming Dinosaur Folios 
entry on this dinosaur; sorry italics and other typographical niceties are 
lost in email:

    ARGENTINOSAURUS

Order: Brontosauria
    Suborder: Sauropoda
        Family: Andesauridae

Describers: José Fernando Bonaparte and Rodolfo A. Coria
Year described: 1993
Etymology: Argentino-, Latinized combining form of Argentina, the country in 
which the type specimen was discovered; and
-saurus, Latinized combining form of sauros, a masculine Greek noun for 
"lizard"; thus, "Argentina lizard"
Type species: Argentinosaurus huinculensis
Current status: Valid genus

    ARGENTINOSAURUS HUINCULENSIS

Describers: José Fernando Bonaparte and Rodolfo A. Coria
Year described: 1993
Etymology: huinculensis, a Latin word meaning "from Huincul," referring to 
Plaza Huicul, the municipality in Neuquén Province, Argentina, where the type 
specimen was discovered and where it is now kept
Average adult size: Approximately 90 feet (27.5 meters) long
Average adult weight: Approximately 50 tons (50,000 kg)
Range: Central South America (west central Argentina)
Period: Late Early to early Late Cretaceous (Albian-Cenomanian stages, about 
90-112 million years ago)
Diet: Plants
Current status: Valid species; type species of the genus Argentinosaurus
General description and taxonomic history:
    Gigantic?not just very large?sauropod dinosaurs have been known from 
Argentina since 1929, when Friedrich von Huene described the 7.5-foot-long 
(231 cm) thigh bones of the Late Cretaceous Antarctosaurus giganteus. The 
latest such discovery, from the same general area where Antarctosaurus 
giganteus was found, establishes the existence of an equally enormous 
sauropod in earlier rocks of Neuquén Province. As usual, no skull material 
was unearthed, but the six enormous dorsal vertebrae and partial sacrum are 
very distinctive. There is little question that the material belongs to no 
previously known Argentine sauropod genus, so its describers have given it 
the new name Argentinosaurus huinculensis.
    Despite their size?almost 5.5 feet tall (165 cm) when complete?the dorsal 
vertebrae of Argentinosaurus were lightly built, with deep, weight-saving 
excavations (pleurocoels) in the vertebral bodies (centra) and thin, bony 
buttresses extending upward from the centra onto the neural spines and 
rib-bearing transverse processes. Powerfully developed "extra joints" 
(hyposphenes and hypantra) between adjacent vertebrae helped to stiffen and 
strengthen the spinal column, to support the creature's tremendous weight. 
The uniquely shaped hyposphenes and hypantra are among the characters 
distinguishing Argentinosaurus as a new genus.
    Most Cretaceous sauropods of South America fall into the family 
Saltasauridae, whose members had undivided neural spines on the neck and back 
vertebrae. Having single neural spines is a primitive character retained from 
prosauropods and basal sauropods such as Cetiosaurus. (The well-known 
"advanced" Late Jurassic sauropods of North America and Asia?Apatosaurus, 
Diplodocus, Camarasaurus, Euhelopus, and Mamenchisaurus?had neural spines 
cleft in two on long stretches of their neck and back vertebrae.) The huge 
vertebrae of Argentinosaurus were all single-spined; but whereas primitive 
sauropods had neural spines that were transversely narrow, like knife blades 
lined up in a row, the neural spines of Argentinosaurus were transversely 
broad: slenderer in side view than in front view. This is different from the 
condition in "true" saltasaurids, whose single neural spines were not 
flattened front-to-back. Furthermore, in saltasaurids the 
hyposphene-hypantrum joints between the vertebrae were poorly developed. So 
although Argentinosaurus is clearly related to the saltasaurids, it is not 
actually one of them.
    José F. Bonaparte and Rodolfo A. Coria, the describers, noted that two 
previously described Argentine "saltasaurids," Andesaurus delgadoi and 
Epachthosaurus sciuttoi, seem more closely related to Argentinosaurus than to 
any "true" saltasaurids. Previously classified in the subfamily Andesaurinae 
of the family Titanosauridae (recently renamed Saltasauridae), these genera 
were removed from Titanosauridae and placed, along with Argentinosaurus, into 
the family Andesauridae, which the describers elevated in rank from 
subfamily. The describers considered Andesauridae and Titanosauridae to be 
sister groups within the larger clade Titanosauria, which they also defined.
    Both Andesaurus and Epachthosaurus were considerably smaller than 
Argentinosaurus. If we assume that Argentinosaurus was built to roughly the 
same proportions as its smaller relatives, we may estimate its overall size 
by scaling up their dimensions. In particular, given a tibia 155 cm long, the 
hindlimb would have had a total length, from hip socket to the sole of the 
foot, of about 4.5 meters (about 14.5 feet). Much of this length, about 2.4 
meters, would have been its thigh bone (femur)?a bit longer than in the 
previous record-holder, Antarctosaurus giganteus. The forelimb would have 
been about equally long: the humerus would have been shorter than the femur, 
but the ulna plus metacarpals would have been longer than the tibia plus 
metatarsals. The ridge of the back would have been at least another meter 
above the ground, particularly in the shoulder region, where it was probably 
higher than at the hips, Brachiosaurus-style. Thirteen or so dorsal 
vertebrae, each more than 50 cm long, add up to a back 6-7 meters long, to 
which we may add another 1.5 meters of sacral vertebrae, 6-7 meters of neck 
(titanosaurian necks seem to have been short and thick), and perhaps 12 more 
meters of tail. (Titanosaurians probably had short, chunky tails, without the 
long whiplashes of the diplodocids?although we do not know this for certain, 
because no complete titanosaurian tail has ever been discovered.) This adds 
up to an animal 25.5 to 27.5 meters (83.5-90 feet) long and about 6 meters 
(20 feet) high at the shoulder.
    This is about as long as the famous Diplodocus carnegii skeleton. But the 
length of Diplodocus comprised mainly neck and tail; its body, independent of 
neck and tail, was not much larger than that of a good-sized African 
elephant. So whereas Diplodocus may have weighed in the neighborhood of 12-15 
tons (12-15,000 kg), Argentinosaurus, with a torso 50% longer, taller, and 
wider, probably weighed almost 3.5 times as much: 40-50 tons. These 
dimensions make it South America's largest known dinosaur.
Type specimen: PVPH-1, a very incomplete skeleton including only 3 partial 
anterior dorsal vertebrae (specificially, the partial neural arch of dorsal 
?1, and dorsals ?2-3 lacking upper parts of the neural spines), 3 partial 
posterior dorsal vertebrae (nearly complete: 2 in articulation, the third 
isolated; all 6 vertebrae with centra about 49 cm in diameter and restored 
total heights of about 120-165 cm), much of the sacrum (incomplete sacrals 
1-5 of a total of 6, plus right sacral ribs), a partial hollow thoracic rib, 
and a nearly complete right tibia 155 cm long, all found in the same place 
and apparently belonging to the same individual; presently in the collection 
of the Museo Municipal "Carmen Funes" at Plaza Huincul, Neuquén Province, 
Argentina
Discoverer: Personnel from the Museo Municipal "Carmen Funes"
When discovered: January-February 1989
Where discovered: In the Huincul Member of the Río Limay Formation, about 8 
km (5 miles) east of the intersection of provincial highway 17 and national 
highway 22, near the hotel "Las Overas" at Plaza Huincul, Neuquén Province, 
Argentina
Other important specimens: None known
Diagnosis: Very large andesaurid sauropod with distinctive 
hyposphene-hypantrum articulations [text incomplete here]
Cranium and mandible: Unknown
Vertebral column: [text incomplete here]
Pectoral girdle: Unknown
Forelimb: Unknown
Pelvic girdle: [text incomplete here]
Hind limb: [text incomplete here]
References: Bonaparte 1989; Bonaparte & Coria 1993