Gondwanaland:Gondwanaland:
South America in the Early Cretaceous
From The Dinosaur Collector
Some of the earliest known dinosaurs are from the Late Triassic South America. Jurassic fossils are rare, we know there were sauropods and theropods. Cretaceous South American dinosaurs have been poorly known. Part of Gondwanaland, it was dominated in the by abelisaurs like Carnotaurus and sauropods. There is a Northern hemisphere bias to dinosaurs since the best known finds especially for the Cretaceous are from Laurasia. It was long assumed that sauropods declined world wide and were replaced by hadrosaurs and cerotopsians. It may be that North America and Asia were not the norm for the Mesozoic. In the The southern continents sauropods thrived and evolved the duckbills and certopsians never became major components of the fauna of South America, Australia or Africa. It actually looks like Gondwanaland fauna was expanding into North America and Europe when the extinction event closed out the Mesozoic. Argentina in particular has been producing a lot of new dinosaur finds. These have been over shadowed by the spectacular finds in Asia in the public news.
update 11/18/10
Find more Diorama pages
From the Hauterivian we have the oldest abelisaurids, a possible stegosaur and Amargasaurus, from the La Amarga Formation in north-west Patagonia. Rebbachisaurus was a large diplodocid sauropod with tall back vertebrae. It is the latest known diplodocoid, and the most complete South American sauropod. Remains have been found in South America and Africa.
Procon Rebbachisaurus.
The Early Cretaceous La Amarga Formation in Patagonia runs through the Barremian through the Early Aptian. There is the medium sized, 37 feet long sauropod Amargasaurus (Amarga lizard) had a “frill” or "spikes" running along most of its neck and back. Diplodocids evolve medium size animals that fill the medium size herbivore niches occupied by ornithscians in the north.
Carnegie Safari and Procon Amargasaurus
These animals seem be related to the same family as Dicraeosaurus found in Africa in the Jurassic. Diplodocids and titanosaurs filled the medium and giant plant eating roles. Small iguanodonts are present reminiscent of the Late Jurassic dryosaurs. Abelisaurs were the medium size predators. They are though to be relatives of the Jurassic ceratosaurs. The earliest known abelisaurs are known from Jurassic North Africa. Abelisaurs seem to be a group that started in Gondwana and moved into Europe in the Cretaceous. The divergence in dinosaur families seems to have begun in the Jurassic become apparent in the Cretaceous.
The Amargasaurus from Chap Mei , FameMaster 4D and the large and small Battat toy figures.
Agustinia is a large sauropod characterized by large dorsal plates. It is probably a diplodocid related to Rebbachisaurus rather than a titanosaur.
Standard Procon Agustinia.
Abelisaurs like Carnotaurus are the common middle sized predators in South America, Africa, India and Europe. Early Cretaceous Ligabueino (meaning "Ligabue's little one") was an abelisaurid or Nassau. This was the smallest of all abelisaurs, only 70 cm (2.3 feet) long.
(Use the scroll bar to view all the Diorama) Battat's Amargasaurus and Carnotaurus. Next from Safari the titanosaur Saltasaurus and Carnotaurus. Last the Jasman Carnotaurus and Tamiya hypsilophidont. While it is unlikely these dinosaurs all lived at the same time, currently the range of South American dinosaur figures is limited in variety. I think it reasonable to assume that they would have had similar animals for most of the period.
Abelisaurs are regarded as primitive theropods perhaps related to the Jurassic ceratosaurs. Most are poorly known from scrappy finds in South America, Africa, Europe and India. The also differed from the allosaurids and tyrannosaurids by not having their tails stiffen by rods. They may not have been as maneuverable on land but potentially better swimmers.
Disney Carnotaurus and a gray Toys and Things Saltasaurus. The blue sleeping Saltasaurus is a custom figure I made based on the Panosh figure.
Back to the Mesozoic
| Triassic |  
|
Spinosaurs |
Click on the Site A icon to the right for Dioramas organized by period or by manufacturer.
