In terms of dinosaurs, 2023 is going to go out like it came in: with a new plus-sized Huincul Formation titanosaur. This one has been delivered just in time for Christmas, although it's unlikely to fit under anyone's tree. Of course, there have been some comments that it is not as big as has been published, but regular readers will know not to get too wrapped up in these things.
Genus and Species: Bustingorrytitan shiva. The genus name honors the landowner Manuel Bustingorry, while the species name invokes the Hindu deity Shiva, the Destroyer, an allusion to the faunal turnover at the Cenomanian–Turonian boundary that occurred not long after the late Cenomanian time of B. shiva (Simón and Salgado 2023). I'm not quite sure how to work the species, but obviously the genus translates roughly to "Manuel Bustingorry's titan".
Citation: Simón, M. E., and L. Salgado. 2023. A new gigantic titanosaurian sauropod from the early Late Cretaceous of Patagonia (Neuquén Province, Argentina). Acta Palaeontologica Polonica in press. doi: https://doi.org/10.4202/app.01086.2023.
Geography and Stratigraphy: The specimens come from the "Bustingorry II" site northwest of Villa El Chocón in central Neuquén Province, central western Argentina. Stratigraphically, we're in the late Cenomanian-age Huincul Formation of the Neuquén Group, 60 m (200 ft) above the "La Antena" quarry that produced fellow titanosaur Choconsaurus baileywillisi, near the base of the same formation (Simón and Salgado 2023).
Holotype: MMCH-Pv 59/1–40 (paleovertebrate collection, Museo Municipal de Villa El Chocón "Ernesto Bachmann", Neuquén, Argentina), which is one where various bones each get their own numbers within the group number 59. There's a little bit of everything, including the right dentary, a tooth, a middle dorsal vertebra, four caudals, a couple of chevrons, both shoulder girdles (scapulae, coracoids, and sternal plates), the left ilium and part of the right, the right pubis, both humeri and ulnae, the right radius, all five right metacarpals, the right femur, tibia, and fibula, the left fibula and astragalus, three metatarsals, and three phalanges (Simón and Salgado 2023). (The bias to the right side suggests to me that the carcass was on its right side.)
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| Figure 5 from Simón and Salgado (2023) (which see for full caption), illustrating the elements of the arm and pectoral girdle of Bustingorrytitan shiva. Scale bars are 200 mm (7.87 in). CC BY 4.0. |
The story of B. shiva appears to go back more than 20 years as the shadowy informal name/typo "Sauropodus". A press release from 2001 that was preserved by the Dinosaur Mailing List matches the formation, location, and lead researcher, and the material is described as including "upper and lower limbs, vertebrae, ribs and a piece of tooth." Apart from the ribs, this is basically the holotype of B. shiva (and does not fit particularly well with any other named contender). The material also was reported in an abstract I haven't seen (Simón 2001), and a thesis I haven't seen (Simón 2011; you can find the abstract here, though), so I cannot comment much on them. (I did, though, find Leonardo Filippi's 2021 doctoral thesis on Sierra Barrosa Formation titanosaurs while looking for it, in case you'd like to see that.)
Not only is there an extensive (if limb- and girdle-dominated holotype), but at least three other individuals are recognized from the same site: the somewhat smaller paratype MMCH-Pv 60/1–6, featuring a cervical, caudal, right ulna, metacarpal, right femur, and left tibia; MMCH-Pv 61/1, an even smaller individual represented by a left femur; and MMCH-Pv 62/1–3, a larger individual than the holotype, represented by a right femur, left tibia, and left astragalus (Simón and Salgado 2023). Between all four of them, all areas of the skeleton are represented except for the cranium, ribs, and sacrum, although the vertebrae are kind of sparse.
With all of that material, B. shiva becomes one of the best represented titanosaurs, and one of the best represented large titanosaurs. The dentary is of the rounded variety, not squared off like our most recent guest Inawentu oslatus. It is low and had at least 12 teeth, but their exact shape is not known because of poor preservation. The only known cervical is from the middle to posterior part of the neck and 540 mm (21 in) long, albeit somewhat smooshed. Interestingly, there are no foramina or pleurocoels. The one dorsal is notable for having a hyposphene and hypantrum, which is interesting because of the handful of other titanosaurs reputed to have this feature, two are also from the Huincul Formation (Cho. baileywillisi and, controversially, Argentinosaurus huinculensis). The caudals also have this articulation, but are otherwise rather typically titanosaurian in form (procoelous, neural arches cheated anteriorly, etc.) (Simón and Salgado 2023).
The forelimb is more complete than the hindlimb, and we can get a pretty good idea of its proportions. For the right arm of the holotype, the humerus is 160 cm (63 in) long (a bit odd compared to the 170 cm [67 in] length of the left humerus), the ulna is 110 cm (43 in), the radius is 97 cm (38 in), and Metacarpal III is 53 cm (21 in), giving an animal with an arm about 3.1 m (122 in) long (Simón and Salgado 2023). The longer of the two humeri is between that of Paralititan stromeri and Notocolossus gonzalezparejasi, becoming the second-longest titanosaur humerus. Despite the size, the humerus is on the gracile side. For the hindlimb, the only complete femur is from the smallest individual, at 160 cm (63 in) long, while the left tibia of the paratype is 110 cm (43 in) long. The femur is robust, while the tibia and fibula are gracile (Simón and Salgado 2023).
Of course, the major talking point for B. shiva is its size. Clearly an animal with the second-longest humerus known for a titanosaur and an arm about 3 meters long is going to be a substantial animal. Simón and Salgado (2023), using limb bone circumferences, presented an estimated range of about 50 to 84.5 metric tons (55 to 93.1 US tons) for the holotype individual, which is not the largest known individual. What is interesting to me is the Huincul Formation also produced Argentinosaurus (still heavyweight champion) and the respectably sized Chucarosaurus diripienda, so it was clearly a good time for growing big titanosaurs. The Huincul is also known for its rebbachisaurids, which conceivably were keeping the titanosaurs out of the smallish sauropod niches. I do wish a bit more space had been devoted to differentiating B. shiva from the three other named Huincul titanosaurs; there were several comments comparing it to Chu. diripienda, but nothing for A. huinculensis or Cho. baileywillisi. A paragraph or two to summarize would have been appreciated. (At least it's better than the Inawentu paper in that regard.) Phylogenetically, B. shiva is found to be distant from A, huinculensis, as the sister to Saltasauridae (Opisthocoelicaudia + Saltasaurus) (Simón and Salgado 2023). This is noteworthy for a couple of reasons, one being that saltasaurids are otherwise basically only known from the last 20 million years or so of the Cretaceous, another being that saltasaurids are not generally noted for their size.
References
Simón, M. E. 2001. A giant sauropod from the Upper Cretaceous of El Chocon. Ameghiniana 38(supplement to 4):19R.
Simón, M. E. 2011. Los dinosaurios saurópodos de la Formación Huincul (Cenomaniano superior) en Villa El Chocón (Neuquén): osteología, relaciones filogenéticas, aspectos paleoecológicos, y paleobiogeográficos. Thesis. Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina.
Simón, M. E., and L. Salgado. 2023. A new gigantic titanosaurian sauropod from the early Late Cretaceous of Patagonia (Neuquén Province, Argentina). Acta Palaeontologica Polonica in press. doi: https://doi.org/10.4202/app.01086.2023.
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