Page 43 - DINOSOUR ATLAS

Auca Mahuevo
42

Sierra Chachahuén south america
6,775 ft (2,065 m)
The souThern parT of souTh america, known as Patagonia, is an area of dry, rocky desert, MENDOZA LA PAMPA
spanning Argentina and Chile. At Auca Mahuevo there is a spectacular dinosaur nesting
site, where the desert surface is littered with the eggs of Late Cretaceous sauropods Sierra de Auca Mahuida Colorado
7,220 ft (2,200 m)
(huge plant-eating dinosaurs), laid 80 million years ago. Ancient Patagonia was also the
Auca Mahuevo
home of predators, including the formidable Giganotosaurus and the smaller Aucasaurus— Cuenca del Añelo
a dangerous visitor that may have fed on the defenseless Auca Mahuevo hatchlings.
N E U Q U É N
RIO
Neuquén
Embalse Cerros
, the landscape todaY Colorados NEGRO
Auca Mahuevo was once a river Lago
floodplain. Sauropods laid their head was Neuquén Pellegrini
eggs on the ground, then lost them 6 ft (1.8 m) long u site location
when a flood covered them with
sediment. Today, these deep The Auca Mahuevo nesting site is in Neuquén Province,
sediments are the region’s western Argentina. Some of the largest dinosaur fossils
siltstones and mudstones. have also been found in this province.

largeSt teeth
were 8 in (20 cm) long

carnotaurus .
This dinosaur was an
odd-looking meat-eater.
Only one specimen has been
found in Patagonia (see page 37
for map reference), farther south of Neuquén.
Remarkably, its skeleton was almost complete, so
paleontologists are certain of its most distinctive
features—tiny arms and short horns above its eyes.

Pebbly-
, GiGanotosaurus textured Skin
The size of this gigantic
carnivore—bigger even than
Tyrannosaurus rex—is hard to imagine.
Its teeth, serrated like steak knives,
were perfect for slicing into the flesh did you know?
of its sauropod prey. Fossil remains , aucasaurus
of this deadly predator were . Some of the eggs at Auca Mahuevo contain Like Carnotaurus, Aucasaurus also
found farther south of the fossilized embryos of unborn sauropods, aucaSauruS had very short arms, but instead
Auca Mahuevo site. complete with impressions of their scaly skin. was only about of horns, bumps grew over its eyes.
It has not been possible to determine which 3 ft (1 m) long The only known example seems to
species of sauropod they are. The eggs are
6 in (15 cm) across, and the hatchlings would have died from head injuries,
have been 12 in (30 cm) long. possibly inflicted in a fight.

saltasaurus .
Ferns, conifers, and ginkgos grew at
the Auca Mahuevo site, providing
food and nesting materials for
sauropods. The identity of the
egg-laying dinosaur is unknown, Short front legS were a
but it is thought to have been a SkeletonS of some weight-saving design that could
titanosaur, possibly Saltasaurus, as sauropods appear to have be lifted off the ground, shifting
the center of gravity to the
been designed to enable them
the skin of babies found at the nest to stand up on their hind legs animal’s rear half tail acted
site has bumps on it, which may like a “third leg,”
have developed into the bony providing stability
nodules known in adults. as it stretched up to
reach the leaves at
the top of trees