ACTIVITY 133:Read the text below, click on the gaps
and decide which word best fits each gap. Then check the correct answers.
In the late 1930s, a group of American scientists
seeking dinosaur fossils made some noteworthy finds. Although
one of their expeditions discovered no fossils, it nonetheless
to be important in terms
of the information about dinosaurs it provided.
During that historic expedition, which took
place along the of the Paluxy river in Texas,
something extraordinary was revealed: a dinosaur track, clearly
in the rock. These dinosaur
footprints their preservation to the
salts and mud that covered them and then hardened into rock, before
to light 100 million years
later. Tracks like these are to experts.
There have been great gaps in scientists' understanding of dinosaur
, and so such footprints are
useful since they provide direct of how dinosaurs actually
moved. Scientists have used these and other footprints to determine
how quickly different species walked, concluding that many kinds of
dinosaur must have travelled in .
the tracks of four-legged
dinosaurs seem to that, in spite of being
reptiles, these creatures must have moved in a very similar way to
living mammals, such as elephants – a pattern of movement
from that of most
contemporary reptiles, such as crocodiles.
This leads to an interesting question. Might existing mammals have
more to teach us about the extinct reptiles that once walked the