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 albertosaurus died out 70mya and tyrannosaurus first appeared 68mya. during that 2my period who would be the apex predator? i've noticed this in other occasions-( north ameeica-allosaurus 144mya,next apex predator utahraptor 131mya,10my). when predatory dinosaurs attacked their prey did they bite in some particular parts of the body of their prey(neck region,hips) or weren't that smart? purrusaurus and other giant crocodylomorphs lived 8 mya in south america that was covered by a giant inland sea. also megalodon lived in south america that time. did these creatures come into conflict? which one of them would have the advantage? Thanks.
ANSWER: Remember, fossils only show a fragment of geological history. They might have been contemporaries for a brief amount of time.
Dinosaur hunting tactics are hard to predict, considering the rather random method used by crocodiles and the more precise methods used by birds. Still, I would say they would target the head, limbs, back, and especially the neck. There are bite marks on hadrosaur tails, stegosaur plates, Triceratops frills and hips, and sauropod limbs and backbones, but it's hard to tell whether the bites came from feeding or scavenging.
There is one example, though, of a predator caught in the act: the "Fighting Dinosaurs" fossil shows a Velociraptor slashing with its claws at the neck and belly of a Protoceratops.
Purusasaurus probably came in contact with Megalodon about as often as saltwater crocodiles come into contact with great white sharks in Australia today. The outcome of any croc vs shark fight is entirely dependent on the water level. If it's fresh, warm or shallow, the croc can maneuver better and defeat the heavier shark. If it's too salty, cold, or deep, the shark can maneuver its body enough to counter and destroy the croc. It'd be rare and dangerous for both opponents, so they probably avoided each other most of the time
I hope this helps
---------- FOLLOW-UP ----------
QUESTION: Hi the average lifespan of a dinosaur species is 5 my. tyrannosaurus first appeared 68mya and lived till 65mya.trough this millions years did he evolved in anyway? a 68mya tyarannosaurus has the same characteristics with a 65 mya tyrannosaurus? scientists say that allosaurus didn't bite and hold on to his prey because he had weak jaws instead he used his jaws as a hatchet tearing chunks of meat till the prey was too weak. if an allosaurus was hunting a medium size ornithopod(camptosaurus) and hold the animal on his jaws the strugglin prey would break the jaws of the allosaurus or he could withstand the struggle of a medium size dinosaur? this was trie for all the allosauris? which do you think is more powerfull animal an adult triceratops,an african bull elephant or a steppe mammoth? thanks and sorry for so many questions.
Answer Tyrannosaurus only remained in one species, and didn't show as much variation as, say, Triceratops (which was once assigned 20 different species). However, most of this is due to the fact that there are so few fossils and it's hard to determine evolutionary change when you only have about 20 good specimens.
I would say that the tactic of the Allosaurus was meant for drawing blood like a shark. Allosaurus could run fairly quickly and the impact would probably stun the Camptosaurus. Holding on is not part of the strategy: it's hit, fall back, grab, and bite. The first charge is meant to put the prey into shock. In addition, Allosaurus had powerful forearms tipped with sharp, hooked claws that could immobilize the prey.
I'd bet on the Triceratops. The African elephant is very intelligent, but its weapons are not evolved to deal with larger predators. Triceratops lived in a world where the top predator was Tyrannosaurus, while the elephant and mammoth only had to deal with lions. The steppe mammoth is taller, but the Triceratops is more robust and its weapons are far more lethal.
