Putting the “Titan” in Titanosaur

You might say that 2018 was kind of a big (dinosaur-sized) year for us at the Field Museum: SUE the Tyrannosaurus rex moved to a new private suite, the cool Antarctic Dinosaurs exhibition was welcomed just in time for summer, and something massive arrived in Stanley Field Hall.

One of the largest known dinosaurs—scratch that, it’s one of the largest land animals to have ever lived—the titanosaur Patagotitan mayorum made its grand debut here in Chicago. But Patagotitan isn’t the first titanosaur at the Field. A juvenile Rapetosaurus from Madagascar and a cast of the femur of Antarctosaurus from Argentina are both on display in the Griffin Halls of Evolving Planet. However, neither quite captures the sheer presence that Patagotitan commands. Here is an introduction to the superstarPatagotitan mayorumand its related kin that put the “titan” in titanosaur!

Patagotitan mayorum

(Carballido et al., 2017)

The most recently discovered giant titanosaur species, Patagotitan mayorum, is known from multiple individuals of various sizes from the same quarry—it’s rare to find so many titanosaur skeletons in one spot. Initially discovered in 2010 at the Mayo family's farm (honorees of the species name, P. mayorum), the excavation took several years to uncover and collect over 130 Patagotitan fossils. Patagotitan hails from the Chubut Province of Argentina within sediments deposited in the Albian, roughly 100 million years ago. The skeletal remains of Patagotitan include most parts of the vertebral column, both pectoral and pelvic girdles, and parts of the fore and hindlimbs. Our cast of Patagotitan is one of only two in the world, with the other currently on display at the American Museum of Natural History in New York City.

Puertasaurus reuili

(Novas et al., 2005)

Hailing from the Late Cretaceous, the remains of Puertasaurus reuili were discovered in the Santa Cruz Province of Argentina. At the time, Puertasaurus was the first gigantic titanosaur to have a preserved vertebra from the neck, as well as three other vertebrae from the back and tail. This important clue hinted at how these large animals were able to hold up their massive, elongated necks and (relatively) small heads. The cervical (neck) vertebra shows enlarged processes, suggesting that the area where neck muscles attached had dramatically increased in size—which would make it easier to hold up such a large neck!

Argentinosaurus huinculensis

(Bonaparte and Coria, 1993)

Argentinosaurus huinculensis historically has been the top titanosaur to beat when it comes to claiming the title of “The Largest Land Animal to Have Ever Lived.” Described in 1993, Argentinosaurus is known from several dorsal vertebrae (backbones), part of the sacrum (part of the vertebral column within the hips), and a tibia from the lower leg. The tibia measures over five feet (1.55 meters)—nearly the length of the humerus (upper arm bone) of Patagotitan. The fossils were recovered from the Neuquen Province of Argentina, and Argentinosaurus lived during the Albian–Cenomanian (~113–94 million years ago).

Paralititan stromeri

(Smith et al., 2001)

Not all of the known gigantic titanosaurs were discovered in South America. On the other side of the Atlantic Ocean, the giant Paralititan stromeriwas unearthed near the Bahariya Oasis in Egypt and lived during the Cenomanian (~100–94 million years ago). Described in 2001, this massive titanosaur is best known from its enormous humerus, measuring around 1.69 meters or almost five and a half feet—at the time, this was the largest humerus known for a titanosaur. Other fossil remains of Paralititan include several vertebrae from the hips and tail, shoulder, ribs, and part of the hand. The fossil remains of Paralititan were found in rock sediments deposited in an estuary-like environment, such as a mangrove. This served as inspiration for the name: paralos is Greek for "near the sea."

Futalognkosaurus dukei

(Calvo et al., 2007)

Our final heavyweight participant, Futalognkosaurus dukei, comes from the Neuquen Province of Argentina and lived during the Turonian–Coniacian (~94–86 million years ago). This enormous titanosaur is currently known from a complete neck and back, sacrum and hips, and a single tail vertebra. Futalognkosaurus provides the best example of the neck construction of these enormous titanosaurs, and just like Puertasaurus, the neural spines in these behemoths are inflated for muscle attachment to hold up such large necks. Recent phylogenetic analyses looking at the family relationships of these jumbo-sized titanosaurs places them in a group called Lognkosauria that includes the namesake Futalognkosaurusas well as Puertasaurus, Patagotitan, and Argentinosaurus.

That's a wrap on some of the biggest titans out there—be sure to stop by and meet our Patagotitan face-to-face. 

References

Bonaparte, J. F., and R. A. Coria. 1993. Un nuevo y gigantesco saurópodo titanosaurio de la Formación Río Limay (Albiano-Cenomaniano) de la Provincia del Neuquén, Argentina. Ameghiniana 30:271–282

Calvo, J. O., J. D. Porfiri, B. J. González-Riga, and A. W. A. Kellner. 2007. A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur. Anais Da Academia Brasileira De Ciencias. 79:529–541.

Carballido, J. L., D. Pol, A. Otero, I. A. Cerda, L. Salgado, A. C. Garrido, J. Ramezani, N. R. Cúneo, and J. M. Krause. 2017. A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs. Proceedings: Biological Sciences 284:20171219–10.

Novas, F., L. Salgado, J. Calvo and F. Angolin. 2005. Giant titanosaur (Dinosauria, Sauropoda) from the Late Cretaceous of Patagonia. Revista del Museo Argentino de Ciencias Naturales 7:31–36.

Smith, J. B., M. C. Lamanna, K. J. Lacovara, P. Dodson, J. R. Smith, J. C. Poole, R. Giegengack, and Y. Attia. 2001. A giant sauropod dinosaur from an Upper Cretaceous mangrove deposit in Egypt. Science 292:1704–1706.