Geoscience Reference
In-Depth Information
Lydekker was also the first paleontologist to recognize the presence
of meat-eating theropod dinosaurs in Patagonia, based on fragmen-
tary remains of fossil skeletons. At the turn of the century, another
British paleontologist, Arthur Smith Woodward, studied a more
complete, yet still fragmentary, skeleton of a theropod from Patago-
nia. Its remains included portions of its imposing jaws, which were
found by Santiago Roth in rocks of the Cretaceous period from the
province of Chubut. Although Woodward named it
Genyodectes
serus,
its fragmentary nature prohibits us from identifying it more
precisely than to say that it is one of the large meat-eating theropods.
Among the early discoveries made in the 1900s was a fragmentary
lower jaw of a horned dinosaur, related to
Triceratops
and its kin, from
late Cretaceous rocks of Chubut. To date, this remains the only
bone of a horned dinosaur ever found in South America. Although its
fragmentary condition raised some doubts about whether it really
belonged to a horned dinosaur, the discovery of footprints from
horned dinosaurs in Bolivia has provided some support for this iden-
tification. However, the shape of a footprint can vary tremendously
depending on whether the animal walked across wet or dry sand or
mud, making them less reliable when identifying extinct animals.
Santiago Roth and other collectors from the La Plata Museum
amassed one of the largest early collections of dinosaurs. Yet, the
importance of Argentina's dinosaur fossils was not internationally rec-
ognized until the 1920s, when a German paleontologist named
Friederich von Huene—one of the most prominent fossil experts of
the early twentieth century—published several detailed studies. He
documented that a wide range of dinosaurs had once inhabited
Patagonia, including meat-eating theropods, giant sauropods, and
horned dinosaurs. But curiously, instead of catalyzing further col-
lecting and research, the seminal work of von Huene arrested scien-
tific investigations of dinosaurs in Argentina until the late 1950s.
At that point, an Argentine biologist interested in evolution,
Osvaldo Reig, initiated a multiyear collecting program in the inhos-
pitable landscape formed by Triassic rocks in northwest Argentina.
Among the numerous vertebrate fossils discovered and studied during
Reig's expeditions were those of the primitive meat-eating dinosaur
Herrerasaurus,
one of the oldest dinosaurs known. Reig described the
skeleton of this menacing, ten-foot-long carnivore in 1963.
