One of the most interesting questions that paleobotanists have helped
answer is what the dinosaurs ate. For many years, people thought that most
dinosaurs were fierce, meat-eating creatures. We now know that most were herbivores.
They probably had tamer personalities.
Using the information below,
prepare your own brief essay on how we know what the dinosaurs ate. Try to
make your writing as clear as possible.
What did the Mesozoic
dinosaurs really eat? This question has spawned numerous hypotheses from scientists,
dinosaur enthusiasts and fantasy writers.
Did dinosaurs feast on certain
ferns? Conifers? Mammals? Each other? We will never completely understand
dinosaur food habits. But scrutiny of the fossil record has revealed a number
of traces of dinosaur feeding activities.
Predator and prey interactions
can occasionally be inferred from the associations of different organisms
in exceptional fossil assemblages. One spectacular find from the Gobi Desert
revealed the skeleton of a carnivorous velociraptor entangled with a herbivorous
protoceratops.
The relative positions of the two dinosaurs suggest
that they were engaged in a struggle when they died.
This association
has often been cited as an example of fighting dinosaurs. But one report disputes
that view. It suggests that the velociraptor was simply feeding on a dead
or dying animal.
This scenario portrays the velociraptor as a scavenger
that died of unknown causes while feeding. A more recent investigation argues
that the taphonomic evidence supports the original predator vs. prey fight
interpretation.
These skeletal associations tell us much about interactions
between different dinosaurs. That's because both predator and prey organisms
have been identified.
Fossil assemblages suggesting clear examples
of predatory behavior are rare, however. They must be carefully scrutinized
so that inadvertent associations of fossil bones are not misinterpreted.
If
theropods dined on other dinosaurs, we might expect to find numerous bite
marks on dinosaur bones. A number of researchers have reported tooth-damaged
dinosaur bone. But the incidence of such traces appears to be considerably
lower than that of marks found on bones from communities with large mammalian
carnivores.
The identity of the animal responsible for bite marks is
usually difficult to determine. That's because many Mesozoic vertebrates (including
crocodiles) were capable of causing generalized tooth damage to bone.
Fortunately,
well-preserved tooth marks can occasionally exhibit distinctive shapes, spacing,
or serration marks that allow comparisons with fossil jaws of contemporaneous
carnivores.
For example, the spacing of the teeth in an allosaurus
jaw was found to match the patterns of scoring found on bones of an apatosaurus.
The
rare occurrence of such carnivorous evidence is another block in the argument
that most dinosaurs were herbivorous. Strong evidence, indeed, but not nearly
as strong as the long plant-fossil record that has since been compiled.
Paleobotanists
have opened a window on the dinosaur's world and the view is mainly of plant
life.
(From: What Did the Dinosaurs Eat, by Indiana University professor
Karen Chin)