AboutDavid Prus Expertise I can answer any general questions about dinosaurs and on prehistoric mammals in the Cenozoic. I also know a bit about the media's various depictions of dinosaurs and their inaccuracies. I don't know much about "microfauna"-small animals, or about Paleozoic besides some knowledge about Permian animals. Plants are right out, I'm afraid.
Experience I have been interested in dinosaurs for most of my life, own a large collection of scientific papers and books on the subject, and am a member of the Field Museum in Chicago.
Education/Credentials I am in college, but studied biology and geology both in high school and as a personal effort.
Question QUESTION: Hi what kind of animals did purrusaurus hunt? in your opinion which predatory dinosaur was the most efficient killer? what was the main prey of utahraptor,what was his hunting method and were any other big predators in his habitat? why lampeosaurus laticaudus was the size of a sauropod when the other hadrosaurs were half his size? why daspletosaurus and albertosaurus became extinct before the end of the cretaceous when no climatic changes happened and their prey was abundant?ceratopsids evolved in asia but only primitive forms lived in asia. why didn't evolv to more advanced ceratopsids like triceratops? Thanks
ANSWER: Purussaurus ate anything it came on-large mammals, large fish, turtles, birds, carrion, other crocodiles, and basically anything it it could bite.
As far as efficiency goes, it really depends on the prey. For huge, fleshy sauropods, the carnosaurs have the right tools for the job. If it's ankylosaurs, tyrannosaurs have the jaws for it. If its small and quick, raptors are perfect. If fish is on the menu, spinosaurs are perfect. It all depends on what they hunt.
Utahraptor was probably an ambush predator hunting alone or in pairs. It probably fed on iguanodonts like Tenontosaurus, Eolambia, and Cedrorestes and juveniles of sauropods like Astrodon, Venenosaurus, and Cedarosaurus. The other big predators were early tyrannosaurs and Acrocanthosaurus.
Lambeosaurus laticaudus may have evolved to a sauropod niche because of its habitat, which was also home to the northernmost titanosaur Alamosaurus. Perhaps the environment encouraged large plant eaters. It's hard to say.
Daspletosaurus and Gorgosaurus were simply replaced by more efficient predators like Tyrannosaurus and Albertosaurus, which were larger and more powerful so they could feed on more powerful prey.
For example, Corythosaurus and Styracosaurus were the common prey for Daspletosaurus and Gorgosaurus. In response, larger species like Anatotitan and Triceratops evolved to counter the predators. In turn, the predators also had to evolve new designs to effectively keep up.
Why no advanced ceratopsians are known in Asia (Turanoceratops is a possible exception) is a mystery, considering how the order started there. It could have been due to the vegetation differences, or disease. It is a true mystery that paleontology is still working on.
I hope this helps
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QUESTION: Hi what was the bite force of deinonychus and dromeosaurus. do you think dromeosaurids were capable of taking down large prey? Did tyrannosaurus share it's environment with other big predators? were dinosaurs more robustly built than todays similar sized mammals? what was the top speed of medium sized ceratopsids(styracosaurus,pachyrhinosaurus...)? Thanks
Answer The Komodo Dragon's bite force is about 40 N, and scaling it up and beefing it up for a large dromeosaur with robust teeth gives us a yield of about 200 N, about as much as a large dog and slightly more than a human.
They probably could take down larger prey by working in packs. There is a famous find of a pack of a dozen Deinonychus killing a Tenontosaurus. Raptors probably could take down large prey if they worked in groups of five, six, or more. Even an individual raptor could take on larger prey-the famous "Fighting Dinosaurs" shows a Velociraptor dying in mortal combat against a slightly larger Protoceratops.
Tyrannosaurus was pretty much alone at the top of the food chain. Interestingly enough, at the same time Tyrannosaurus first appeared, Albertosaurus and the giant alligator Deinosuchus both went extinct. It looks like Tyrannosaurus simply muscled them aside and gained a monopoly.
As far as robusticity goes, it really depends. A moose-sized Gallimimus is a lot more slender, while an elephant-sized hadrosaur is about the same build. Other dinosaurs like the anklyosaurs and ceratopsians were very robust, while others like small theropods such as ornithomimids and dromeosaurs were a lot more gracile. I've seen the skeleton of a bear compared to a similarly sized Dilophosaurus, and the bear is much more robused.
Ceratopsians were not very fast, but probably used their muscular limbs to go at around 15 to 20 miles per hour.
