While a meteor impact was once thought to have caused the extinction of dinosaurs, some scientists now believe evidence points to other factors. A newly discovered dinosaur relative found in Tanzania that lived 243 million years ago provides evidence that dinosaurs originated 10 million years earlier than previously believed. Most dinosaurs were herbivores that ate plants like conifers, ferns, mosses and cycads, though some were carnivores that hunted other dinosaurs or scavenged carcasses. Over time, terrestrial amphibians and swamp lizards evolved further into the first dinosaurs.

1. By Riley

2. What did kill the dinosaurs?
• Until recently most scientists thought they knew what
killed off the dinosaurs. A 10km-wide meteorite had
smashed into the Yucatan peninsula in Mexico, causing
worldwide forest fires, tsunamis several kilometres
high, and an 'impact winter' - in which dust blocked out
the sun for months or years. It was thought that the
dinosaurs were blasted, roasted and frozen to death, in
that order.
• But now a small but vociferous group of scientists
believes there is increasing evidence that this 'impact'
theory could be wrong. That suggestion has generated
one of the bitterest scientific rows of recent times.

3. How old were the dinosaurs?
• A new dinosaur relative found in Tanzania is the oldest
known creature of its kind—a discovery that pushes
back the origin of dinosaurs by at least ten million
years, paleontologists say.
• Dubbed Asilisaurus kongwe, the Labrador retriever-size
creature was a silesaur, the closest relatives to true
dinosaurs. The newfound animal lived 243 million years
ago, during the middle Triassic period.
• Since silesaurs and true dinosaurs diverged from a
common ancestor, the two groups should have existed
during the same time frame. But the oldest known true
dinosaurs date back to just 230 million years ago.

4. What did the dinosaurs eat?
• Some dinosaurs ate lizards, turtles, eggs, or early mammals.
Some hunted other dinosaurs or scavenged dead animals.
Most, however, ate plants (but not grass, which hadn't
evolved yet). Rocks that contains dinosaur bones also
contain fossil pollen and spores that indicate hundreds to
thousands of types of plants existed during the Mesozoic
Era. Many of these plants had edible leaves, including
evergreen conifers (pine trees, redwoods, and their
relatives), ferns, mosses, horsetail
rushes, cycads, ginkos, and in the latter part of the dinosaur
age flowering (fruiting) plants. Although the exact time of
origin for flowering plants is still uncertain, the last of the
dinosaurs certainly had fruit available to eat.

5. What made the dinosaurs?
• When earth had only water dinosaurs were
fish. They then evolved into giant frogs and
then into dinosaurs. When earth got more
land, swampy lizards evolved into dinosaurs.