Dreadnoughtus
Dreadnoughtus [1] is a genus of giant titanosaurian dinosaur. Its fossilised skeleton was found in the Upper Cretaceous of Santa Cruz province, Argentina. These rocks date from 84–66 million years ago (mya).
| Dreadnoughtus | |
|---|---|
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| Skeletal restoration showing known elements | |
Scientific classification 
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| Unrecognized taxon (fix): | Bagualosauria |
| Clade: | Lithostrotia |
| Genus: | Dreadnoughtus Lacovara et al., 2014 |
| Species: | D. schrani
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| Binomial name | |
| Dreadnoughtus schrani Lacovara et al., 2014
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This is one of the largest of all known terrestrial vertebrates. It has the greatest mass (weight) of any land animal that has been calculated.[2] They used using limb bone measurements for the calculation.[3][4]
Dreadnoughtus schrani is the most complete skeleton of a large titanosaurian sauropod dinosaur.[2] Types of bones is the most important statistic. The completeness statistics for Dreadnoughtus schrani are as follows:
- 116 bones out of ~256 in the entire skeleton (including the skull) = 45.3% complete
- 115 bones out of ~196 in the skeleton (excluding the skull) = 58.7% complete
- 100 types of bones out of ~142 types in the skeleton (excluding the skull) = 70.4% complete
The specimen was probably not fully grown at the time of its death. The histology of its humerus, shows a lack of an outer layer of bone found only in fully-grown vertebrates. There is a lot of fast-deposited or still-growing bone tissue. Therefore, the specimen was still growing at the time of its death.[2][5] It is unknown how large this individual would have grown if it had lived a full life.
Estimates
As a matter of basic science, the estimates of dimensions such as the mass (weight) of extinct animals are very rough figures. To avoid the pretence of spurious accuracy. we only give rounded figures here. Moreover. all the skeletons are incomplete, which means that even length (the easiest dimension to estimate) cannot be given exactly. Published estimates by scientists are just that: estimates. Estimation is an approximation given when information is not clear or is incomplete. It is like making an educated guess.
It is usual for estimates of mass (weight) to vary between experts. Using the same basic data, the weight of Dreadnoughtus has been estimated as:
- About 59.3 metric tons (65.4 short tons), or 59,291 kilograms.[2]
- Between 35 and 40 metric tons (39 to 44 short tons),[6]
- About 30 metric tons (33 short tons), based on a 20% shorter torso.[7]
There is a ~x2 difference between the heaviest and lightest estimates, and that is not at all unusual for this type of calculation.
Size
| Dimension | metric | imperial |
|---|---|---|
| Mass | 59,300 kilograms (59.3 t) | 65.4 short tons (130,800 lb) |
| Total length | 26 m | 85 ft |
| Head and neck length | 12.2 m | 40 ft |
| Neck-only length | 11.3 m | 37 ft |
| Torso and hip length | 5.1 m | 17 ft |
| Tail length | 8.7 m | 29 ft |
| Shoulder height | ~ 2 stories (6 m) | ~ 2 stories (20 ft) |
Comparisons
| Sauropod | Group | metric tons | short tons |
|---|---|---|---|
| Dreadnoughtus schrani | Titanosauria | 59.3 [2] | 65.4 |
| Brachiosaurus altithorax | Brachiosauridae | 56.3 [3] | 62.1 |
| Turiasaurus riodevensis | Turiasauria | 50.9 [3] | 56.1 |
| Elaltitan lilloi | Titanosauria | 42.8 [3] | 47.2 |
| Futalognkosaurus dukei | Titanosauria | 38.1 [3] | 42 |
| Giraffatitan brancai | Brachiosauridae | 34 [3] | 37.5 |
| Diplodocus longus | Diplodocidae | 14.8 [3] | 16.3 |
Dreadnoughtus Media
Paleontologist Kenneth Lacovara in Patagonia with the Dreadnoughtus femur (thighbone)
Size of the type specimen compared with a human
Life reconstruction of Dreadnoughtus schrani
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References
- ↑ meaning "fearing nothing" and a type of warship
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Lacovara, Kenneth J.; et al. (2014). "A gigantic, exceptionally complete titanosaurian sauropod dinosaur from southern Patagonia, Argentina". Scientific Reports. 4: 6196. doi:10.1038/srep06196. PMC 5385829. PMID 25186586.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Benson, Roger B.J.; et al. (2014). "Rates of dinosaur body mass evolution indicate 170 million years of sustained ecological innovation on the avian stem lineage". PLOS Biology. 12 (5): e1001853. doi:10.1371/journal.pbio.1001853. PMC 4011683. PMID 24802911.
- ↑ Campione, Nicolás E.; Evans, David C. (2012). "A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods". BMC Biology. 10: 15. doi:10.1186/1741-7007-10-60. PMC 3403949. PMID 22781121.
- ↑ Schroeter, Elena; Boles, Zachary; Lacovara, Kenneth (2011). "The histology of a massive titanosaur from Argentina and implications for maximum size" (PDF). Journal of Vertebrate Paleontology (Program and Abstracts Supplement): 189. Archived from the original (PDF) on 2013-10-07. Retrieved 2014-09-06.
- ↑ Matt Wedel (11 September 2014). "How massive was Dreadnoughtus?". svpow. Retrieved 11 September 2014.
- ↑ Matt Wedel (15 September 2014). "How long was the torso of Dreadnoughtus?". svpow. Retrieved 15 September 2014.