Heads up: intact skull sheds light on big, long-necked dinosaurs

[nitpicker]

http://uk.reuters.com/article/us-science-dinosaur-idUKKCN0XN2DQ

Technology | Tue Apr 26, 2016 10:30pm BST
Related: Science, Life

Heads up: intact skull sheds light on big, long-necked dinosaurs

WASHINGTON | By Will Dunham

A beautifully preserved fossil skull unearthed in Argentina is giving scientists unparalleled insight into the sensory capabilities and behavior of a group of dinosaurs that were the largest land animals in Earth's history.

Scientists announced on Tuesday the discovery of the skull as well as neck bones of a newly identified dinosaur called Sarmientosaurus that roamed Patagonia 95 million years ago. CT scans of the skull revealed its brain structure and provided close understanding of its hearing, sight and feeding behavior.

Sarmientosaurus, about 40-50 feet long (12-15 meters) and 8-12 tons, belonged to a group called titanosaurs, plant-eating dinosaurs known for long necks, long tails and huge bodies. Sarmientosaurus was a medium-sized titanosaur. The largest species exceeded 100 feet (30 meters) and 50 tons. Of the 60 known titanosaur species, only four, including Sarmientosaurus, have been found with complete skulls.
(snip)

Its skull provided the best information on brain structure for any sauropod, Witmer said.

Its hearing organ, the cochlear duct, was long, indicating good hearing of low-frequency sounds transmitted over long distances, perhaps to keep track of other members of the herd when they were out of sight, Witmer said.

Its eye sockets and eyeballs were relatively large, suggesting vision was particularly important for Sarmientosaurus, Witmer added.

Its inner ear orientation on the skull indicates Sarmientosaurus had a nose-down head posture and that it fed mostly on ground plants rather than cropping leaves from tall trees, Witmer said.
(snip)

[eppur_se_muova]

1. Sauropod skulls were unfortunately fragile, and seldom found with the other remains ...

this has caused considerable confusion re. taxonomy:

The skull of Apatosaurus was confused with that of Camarasaurus and Brachiosaurus until 1909, when the holotype of A. louisae was found, and a complete skull just a few meters away from the front of the neck. Henry Fairfield Osborn disagreed with this association, and went on to mount a skeleton of Apatosaurus with a Camarasaurus skull cast. Until 1970, Apatosaurus skeletons were mounted with speculative skull casts, when McIntosh showed that more robust skulls assigned to Diplodocus were more likely from Apatosaurus.

Apatosaurus is a genus in the family Diplodocidae. It is one of the more basal genera, with only Amphicoelias, and possibly a new, unnamed genus more primitive. While the subfamily Apatosaurinae was named in 1929, the group was not used validly until an extensive 2015 study. Only Brontosaurus is also in the subfamily, with the other genera being considered as synonyms or reclassified as diplodocines. Brontosaurus has long been considered a junior synonym of Apatosaurus; its only species was reclassified as A. excelsus in 1903. However, the 2015 study concluded that Brontosaurus was a valid genus of sauropod distinct from Apatosaurus. As it existed in North America during the late Jurassic, Apatosaurus would have lived aside dinosaurs such as Allosaurus, Camarasaurus, Diplodocus, and Stegosaurus.

https://en.wikipedia.org/wiki/Apatosaurus

Nice to see Wiki confirms Brontosaurus is back.

http://www.democraticunderground.com/122837708