Bruhathkayosaurus

*Bruhathkayosaurus matleyi*

**Bruhathkayosaurus** is a massive sauropod dinosaur; with holding the candidate for being the most massive/largest dinosaur ever to exist; from the early Maastrichtian, Late Cretaceous of India. It was one of the largest animals known, and the largest dinosaur found to date, with a length of 33 to 44.1 meters and a size of up to *110-170 tons*.

## Discovery

Only the hip and a few leg bones have ever been discovered. Its remains were found in the late 1980's in the southern tip of India in the Kallemedu Formation northeast of Kallamedu village.After it's discovery it was thought to be a theropod dinosaur like Allosaurus. But some scientists told that if it did exist it has to be a titanosaur. However, soon after discovery, these remains were lost to a monsoon. Only the original description and line drawing of the hip and leg bones remain to represent it ever existed at all.

## Classification

It was originally classified as a carnosaur (like Allosaurus ), a subgroup of theropods. Chatterjee in 1995 reclassified it as a titanosaurid. The reclassification was based on the massive size of the limbs, and the structure of the pelvis.

The original publication describes small features in the diagnosis, which were inferred only from a few drawn lines. This has led to speculation that the bones might actually be fossilized wood, an idea stemming from the fact that the original discoverers of Sauroposeidon were initially convinced they were witnessing the fossilized remains of a tree.

## Size estimates

According to the published description, the tibia (shin) of Bruhathkayosaurus is two meters (6.56 feet) long, and the fragmented femur is 75 centimeters (2.46 feet). Due to the lack of skeleton, the length, weight, and height of the creature is mostly speculation, and estimates have varied greatly. No size estimates has ever been published but some estimates have been published in internet. Some paleontologists from Los Angeles in 1996 estimated it's size to be 30 meters. But in 2008, a paleontologist estimated it's size to be 40-44 m but again he said his previous estimation was wrong and the real size was 28–34 m.But the first size estimation was mainly accepted by media and public. It seems to be inferred that Bruhathkayosaurus would have had a very bulky build and would have been much heavier than other sauropods.

Since B. matleyi was reclassified as a titanosaurid, there has been speculation about its large size, but because no size estimates for Bruhathkayosaurus were published at the time , only a few researchers and paleontologists have suggested some tentative estimates on the Internet. An initial estimate by Mickey Mortimer indicated that Bruhathkayosaurus may have reached 40–44 meters in length and weighed between 175–220 tons. 1 However, Mortimer later reneged on these estimates, reducing the estimated length of Bruhathkayosaurus to 28–34 meters and declined to provide a new weight estimate, describing his old estimate as incorrect. In a May 2008 article on the Sauropod Vertebra Picture of the Week weblog , paleontologist Matt Wedel used a comparison to Argentinosaurus and estimated the weight of Bruhathkayosaurus at over 139 tons.

For comparison, it is estimated that the titanosaur Argentinosaurus reached 34.6 meters in length, and would have weighed between 80–100 tons. Another large titanosaur, Paralititan , was probably about 31.9 meters long and weighed about 65–80 tons. 5 All of these sauropods are known only from fragmentary remains, so their estimates of physical magnitude are uncertain. Length is calculated by comparing the bones with their counterparts in similar dinosaurs, which are known from more complete skeletons, and isometric extrapolation is performed. However, such extrapolation can never be more than informed speculation and the length of the queue, in particular, is often very difficult to determine. Determining mass is even more difficult, because there is very little evidence of fossil tissues surviving in the fossil record. Additionally, isometric extrapolation is based on the assumption that body proportions remain the same, which is not necessarily the case. In particular, the proportions of titanosaurs are not well known, due to the limited number of relatively complete specimens.

If the size estimates for Bruhathkayosaurus are accurate, the only animal that would come close in size is the blue whale. Adult blue whales can reach 30 meters in length, which is somewhat shorter than Bruhathkayosaurus , but because the largest blue whales weigh up to 176 tons, 7 they are probably heavier than Bruhathkayosaurus .

Another genus of sauropods that has been proposed as a weight rival to Bruhathkayosaurus is Amphicoelias , of even more dubious existence. It is a diplodocid that is estimated to have had a maximum mass of 185 tons, and would have reached 62 meters in length. Similar in size would have been another sauropod not yet studied in Australia called Brontopodus , known only from its footprints.

When Bruhathkayosaurus was still considered a theropod, it was estimated to be about 18 to 20 m. long, and a weight of 11 to 15 tons. These dimensions are substantially larger than even those of the largest terrestrial carnivores, such as Giganotosaurus , Tyrannosaurus , Spinosaurus , and Carcharodontosaurus . None of these giant predators are believed to have exceeded 15 m. in length, and 8 tons in mass.

Its name comes from the Sanskrit bruhath (बृहत) "large, heavy", and kāya (काय) "body", plus the traditional Greek suffix sauros , lizard with which the name means "reptile with a huge body", 9 may have been the heaviest genus of dinosaur of all. However, this assertion is surrounded by strong controversy and debate: all estimates are based on the original paper by Yadagiri and Ayyasami from 1989, which announced the discovery. Its technical description is so poor that the authors originally classified it as a theropod dinosaur, a member of a large group of carnivorous bipedal dinosaurs that includes Tyrannosaurus ; but a review of their data in 1995 revealed that the remains would have actually belonged to a sauropod (specifically, a titanosaur), a member of a very diverse group of long-necked, long-tailed quadrupedal herbivorous dinosaurs, such as Argentinosaurus . In 2006, the first published reference to Bruhathkayosaurus as a sauropod appeared in a publication on Malagasy vertebrates by David Krause and colleagues.

The monsoon season combined with the sands and clays of the Kallemedu Formation create water-saturated fossils which are extremely friable. During the dry season expansion during the day and contraction at night can cause fossils to break apart. This causes the bones to be poorly preserved and may be impossible to remove without breaking them. In 2017, Peter Galton and Ayyasami reported that Bruhathkayosaurus fossils began to disintegrate into their casings in the ground before the Geological Survey of India (GSIH) took care of them and no longer exist.

Bruhathkayosaurus was found near the southern tip of India, specifically in the Tiruchirapalli district of Tamil Nadu, northeast of the village of Kallamedu. It was recovered from the rocks of the Kallemedu Formation, which date to the Maastrichtian faunal stage of the Cretaceous period. The supposed animal would have lived towards the end of the Mesozoic era, about 70 million years ago.

The fossilized remains include the hip bones (ilium and ischium), a piece of a foreleg bone (femur), a leg bone (tibia), a forearm bone (radius), and a of the tail (vertebrae, specifically a caudal platicel center).

If the authenticity of the find is considered, the genus of Bruhathkayosaurus would currently have only one known species, B. matleyi , the one that was erroneously described by Yadagiri and Ayyasami in 1989 (and not in 1987, as some sources erroneously indicate).

It was originally classified as a carnosaur (like Allosaurus ), a subgroup of theropods. Chatterjee in 1995 reclassified it as a titanosaurid. The reclassification was based on the massive size of the limbs, and the structure of the pelvis.

The original publication describes small features in the diagnosis, which were inferred only from a few drawn lines. This has led to speculation that the bones might actually be fossilized wood, an idea stemming from the fact that the original discoverers of Sauroposeidon were initially convinced they were witnessing the fossilized remains of a tree.

It's size has been estimated at 28 meters, which is longer than the sauropods like Brachiosaurus. Bruhathkayosaurus was probably the largest dinosaur ever found in India, so far.

More recent estimates was conducted after new unclassified images of Bruhathkayosaurus emerged. A 2022 review by Pal and Ayyasami had confirmed that the skeleton photos were real, the genus is likely valid and that the sauropod likely existed after all. These new photos bared light on additional estimations. In 2019, Gregory S Paul gave estimations that Bruhathkayosaurus likely tipped the scales at around 80-120 tons and was 35-40 meters long. In 2023, Gregory Paul and Asier Larramendi collaborated on a new scale. By using various sauropods of different built and design as a template, they estimated that Bruhathkayosaurus would have weighed as much as 170 tons maximum, rivaling the largest Blue Whale in scale. Although more realistic measurements still placed it between 110-130 tons. If these estimates were accurate, it would place Bruhathkayosaurus by far the largest terrestrial animal to have ever lived and rivaled the largest Blue Whales in existence.

## JPInstitute.com Description

This giant dinosaur with a really long name could be the biggest dinosaur ever discovered. For several years it was thought to be a gigantic meat-eater, but it was recently classified as a sauropod, the long-necked family of dinosaurs that includes Argentinosaurus. Bruhathkayosaurus was among the largest dinosaurs that ever lived and would have been an awesome sight to see. Good thing for T. Rex it wasn't a meat-eater because Bruhathkayosaurus was about twice as big!

Some scientists don't think that the Bruhathkayosaurus fossils clearly illustrate the dinosaur's size. These scientists believe the actual size may have been somewhat smaller, but still very impressive.

## Links

https://web.archive.org/web/20031006225940fw\_/http://www.jpinstitute.com/dinopedia/dinocards/dc\_bruha.html

## References

* https://dinosaurpictures.org/Bruhathkayosaurus-pictures
* https://www.thoughtco.com/bruhathkayosaurus-1092699
* https://kidadl.com/dinosaur-facts/bruhathkayosaurus-facts
* https://www.mindat.org/taxon-P77395.html
* https://www.nationalgeographic.com/science/article/biggest-dinosaur-ever-maybe-maybe-not
* https://svpow.com/category/titanosaur/bruhathkayosaurus/
* http://gspauldino.com/DinoArtSauropods.pdf
* https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780552/
* http://www.gspauldino.com/Titanomass.pdf
* https://www.idunn.no/doi/10.18261/let.56.2.5