Herbivore dinosaurs...

[DinoFan83]

There is a very large sauropod humerus from Thailand mentioned in an abstract. It's very likely the largest titanosaur humerus we have so far if the measurement is correct.

The abstract is as follows:
"THE GIGANTIC TITANOSAURIFORM SAUROPOD FROM THE EARLY CRETACEOUS KHOK KRUAT FORMATION IN THE NORTHEASTERN OF THAILAND: A PRELIMINARY REPORT KHANSUBHA, Sasidhorn, Department of Mineral Resources, Bangkok, Thailand; POTHICHAIYA, Cherdchan, Department of Mineral Resources, Bangkok, Thailand; RUGBUMRUNG, Mana, Department of Mineral Resources, Bangkok, Thailand; MEESOOK, Assanee, Department of Mineral Resources, Bangkok, Thailand

Here is a preliminary report on the most recent find of an immense sauropod from the Early Cretaceous Khok Kruat Formation at Ban Pha Nang Sua, Nong Bua Rawe District, Chaiyaphum Province, Northeastern Thailand. In early March 2016, a local villager found an exposed of a sauropod sacrum at the bank of pond in the village. Later, geologists from the Department of Mineral Resources have investigated and started a systematic excavation during April-June 2016, discovered several post-cranial specimen from an individual sauropod comprising an axial skeleton (dorsal vertebra and sacral vertebrae) and an appendicular skeleton (a complete well-preserved right humerus, 1.78 m in length, a large dorsal ribs, a partial small rib, two pieces of partial right femur, pelvic girdle and many bone fragments), found associated with several isolated teeth which belong to Allosaurid and Spinosaurid theropods. Associated faunas include Hybodont shark Heteroptychodus sp. and crocodilian teeth. According to a preparatory study on humeral morphological features suggested that this new find possibly belong to a new taxon of giant titanosauriform sauropod dinosaur from the Khok Kruat Formation of Northeastern Thailand Lithostratigraphically, the sequence of the Khok Kruat Formation at the Pha Nang Sua dinosaur site, can be divided into nine units i.e., Units 1-9, having approximately 3.96 m thick. Dinosaur bones and fragments are found in the lower part of the sequence consisting mainly of reddish brown sandstones and siltstones with conspicuous climbing ripple lamination of Units 1-3. The top of this part consists of a thin layer (Unit 4) of calcrete paleosol. Sandstones from Units 5-9 display various directions of cross bedding and the bones are absent. This may indicate that the dinosaur bones are found in the crevasse splay layers and the channel and channelized sandstone are represented by the sandstones of the upper part of the sequence. The rocks are interpreted as having been deposited by the meandering rivers for Khok Kruat Formation in semi-arid to arid paleoclimate. More details on anatomical and phylogenetic studies and further excavations are essential to complete and compare with other vicinity sauropods. The measured section and faunal assemblage from Ban Pha Nang Sua dinosaur site is not only useful for lithostratigraphic and faunal correlations to other vertebrate sites. This new dinosaur locality will also shade light and figure out more understanding on sauropod evolution, distribution and paleoenvironment in this region."

Given that it appears to be classified as a titanosaur and was found very close geographically and temporally to Phuwiangosaurus, it's likely a good idea to use the latter to scale the humerus.

As for mass, Greg Paul (2016) estimates Phuwiangosaurus at 17 tonnes, and following Klein and Sander (2009) on its histology, the largest humerus from it is 110 cm long. Isometrically scaling from a 17 tonne Phuwiangosaurus with a 110 cm humerus, this specimen ends up at 72 tonnes. So this is undoubtedly a very large animal as the abstract suggests.

Lengthwise, this animal was likely upwards of 30 meters. Paul estimates Phuwiangosaurus at 19 meters, which would lead to a 30.5 meter long animal scaled up isometrically. However, as sauropods grew larger their necks would have grown to the power of 1.35 in respect to torso length (link), so this is likely not long enough. This skeletal from Paleocritti can help us quantify how much this length increase would be.
The neck is about one third of the total length, and would thus be about 10.17 meters on a 30.5 meter Phuwiangosaurus-like form. Applying neck allometry (10.17x1.35-10.17) gives us about 3.55 meters of 'extra' length to add onto the extrapolated 30.5 meters.

Overall, provided this scaling holds, this appears to be an animal approximately 34 meters long and 72 tonnes in weight. Reply