National Geographic  The Oldest Big Cat, From the Roof of the
World  If you placed a tiger next to a lion, it would be
ridiculously easy to say which was which. If you placed their
skeletons next to each other, the task would be far more
difficult. Stripped of their distinctive coats, the 37 species
of cats look much the same as each other. Some are big, others
small, but their bones share similar proportions and features.
Even experts have a tough time telling them apart.  So, when
fossil-hunters find the remains of a new prehistoric cat, they
can take a long time to work out what they just dug up.  That
certainly happened to Jack Tseng from the American Museum of
Natural History in New York. In 2010, he travelled to Tibet with
his wife and other palaeontologists, and discovered a large
collection of fossils. Among the bones were the skull of a large
cat and several fragments of jaws and teeth. “We spent the next
three years trying to find out what this thing was.”  They now
know that they have found the old