Correct Answer: A
Explanation:
Scientists have discovered the remains of humankind's oldest mammal ancestor - a tiny rat-like creature that lived 145 million years ago.
The fossils of the nocturnal mammal were discovered on the Jurassic Coast of Dorset, by palaeontologists from the University of Portsmouth in the U.K.
The animal is the earliest in the line that evolved into humans, and branched off into creatures as diverse as blue whales and pigmy shrews.
The new species has been named Durlstotherim newmani - after an amateur palaeontologist and pub owner Charlie Newman, who helped scientists collect the new specimens.
Researchers were sifting through small samples of earliest Cretaceous rocks when they unexpectedly found two teeth.
The teeth are of a highly advanced type that can pierce, cut and crush food.
Mammal teeth evolved over time, from very simple ones that were not very efficient, to molar-like ridged teeth which could tear, chew and grind food very easily.