Researchers were working to determine the evolutionary history of modern horses using fossils of four horse ancestor species in North America. They had incomplete data for some of the fossils.
This is the data available to the researchers.
Species Fossil Location Percent Uranium 235 Decay
Mesohippus Colorado 3.2
Merychippus Montana 1.7
Dinohippus Montana Unknown
Orohippus Wyoming 5.4
Based on the data presented, what is the order of the fossils from most distant to most recent ancestor?
a. Mesohippus, Dinohippus, Orohippus, Merychippus
b. Dinohippus, Merychippus, Mesohippus, Orohippus
c. Merychippus, Orohippus, Dinohippus, Mesohippus
d. Orohippus, Mesohippus, Merychippus, Dinohippus
