Name: Elaltitan
(Elal titan - After the god of the Tehuelche people).
Phonetic: E-lal-tie-tan.
Named By: Philip D. Mannion & Alejandro
Otero - 2012.
Classification: Chordata, Reptilia, Dinosauria,
Saurischia, Sauropodomorpha, Sauropoda, Titanosauria,
Lithostrotia.
Species: E. lilloi (type).
Diet: Herbivore.
Size: Uncertain but possibly as much as 18
to 20 meters long (refer to main text).
Known locations: Argentina, Chubut Province -
Bajo Barreal Formation.
Time period: Cenomaian/Turonian of the Cretaceous.
Fossil representation: Partial post cranial skeleton.
Like with many dinosaurs, the remains of Elaltitan were originally described as belonging to another genus. Originally assigned by Bonarparte and Gasparini to Antarctosaurus in 1979, the remains were later described as Argyrosaurus by Jaime Powell. Later study of the remains by Philip Mannion and Alejandro Otero led to several key differences being noted, particularly the neural arches of the vertebrae. This led to the conclusion that the remains were those of a very distinct genus of titanosaurian sauropod dinosaur. This led to the creation of Elaltitan, a combination of the name of the god for a local people combined with the ancient Greek titan, from a race of giants that once ruled the world before they were overthrown by the Olympian gods. In fact the term ‘titan’ has been used as the basis for a lot of sauropod dinosaur remains because of their large physical sizes. The species name E. lilloi is in recognition of the work of Miguel Lillo.
Elaltitan
is yet another sauropod dinosaur known from the Cretaceous era deposits
of South America. During the Cretaceous, sauropods, particularly
titanosaurian ones, were still roaming across the globe, though in
most places it seems that they were in far fewer numbers to what they
had been back at the end of the Jurassic when the number of known
remains are most numerous. South America however seems to have been a
refuge for these giant dinosaurs that not only allowed them to hang on
but also to thrive with such truly gigantic forms such as
Argentinosaurus.
This may have been down to South Americas increasing
isolation from the rest of the world as the continents continued to
drift apart, something that would limit the influx of new creatures
into South America, but would also stop sauropods expanding back out.
Like
with most other sauropods, the best defence that Elaltitan
would have
had against predators would have been its large size, although it is
still unknown if Elaltitan had bony armour similar
to some other
titanosaurs such as Saltasaurus.
Because the remains of Elaltitan
are
incomplete it is hard to be certain as to exactly how big it was.
However, although Elaltitan is seen as different
from
Antarctosaurus, the femur of Elaltitan
seems to have been roughly the
same size as the femur of Antarctosaurus. If the
rest of the missing
skeleton of Elaltitan was scaled the same as Antarctosaurus,
then its
plausible that Elaltitan may have been of similar
overall size,
roughly some eighteen metres long. It should be remembered however
that big animals will always be at risk from big predators, and
Elaltitan, particularly smaller juveniles, may
have been at risk of
attack from large theropod dinosaurs such as Giganotosaurus
and
Mapusaurus.
Further reading
- A reappraisal of the Late Cretaceous Argentinean sauropod dinosaur
Argyrosaurus superbus, with a description of a new titanosaur genus. -
Journal of Vertebrate Paleontology 32(3):614-638. - P. D. Mannion
& A. Otero - 2012.
- Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of
Sustained Ecological Innovation on the Avian Stem Lineage. - PLoS
Biology. 12 (5). - R. B. J. Benson, N. S. E. Campione, M. T. Carrano,
P. D. Mannion, C. Sullivan, P. Upchurch & D. C. Evans - 2014.
- Cope's rule and the adaptive landscape of dinosaur body size
evolution. - Palaeontology. 61 (1): 13–48. - R. B. J. Benson, G. Hunt,
M. T. Carrano, N. Campione & P. Mannion - 2018.
- Dinosaur Facts and Figures: The Sauropods and Other Sauropodomorphs.
- New Jersey: Princeton University Press. p. 266. - Molina-Perez
& Larramendi - 2020.