Question

The earliest fossil form in the phylogeny of a horse is
A. Marianas
B. Mesohippus
C. Eohippus
D. Equus

Answer 1

Hint: The horse belongs to mammals, which is family Equidae, they are from geologic time, which is 50 million years ago, and they transformed from small dog size animal to modern horse, and they mostly found in North America, as they originated in North America.

Complete answer:
The horse belongs to the Order Perissodactyla.
They have hoofed feet, and in a horse, the foot contains the odd number of toes.
They have mobile upper lips and similar tooth structures.
The common ancestors of the modern horse are Tapir and Rhinoceroses.
They are usually found in the tropical forest.
The evolution of the horse began with small size animals to the Eohippus and finally developed to the Modern horse.
The first old world equid fossil of a horse was found in gypsum quarries.
When coming to other options, Mesohippus, it arose from Hyracotherium, and was evolved 3 crore years ago, the characters include, it used to look like the size of a modern ship, they have 3 nailed digits, and the middle digit is longest, which generally support the whole body.
Another genus is Equus, it includes all extant equines, it is the oldest species and it is described as Zebra like with donkey shaped head. The oldest fossil of this was found 3 million years ago, when it comes to features, they have long necks, snout, and molars.

So the correct answer is Eohippus.

Note:
The phylogenetic sequence of a horse, the first species is Eohippus, and the Mesohippus arose from Hyracotherium, and Merychippus from Mesohippus, and the Pilohippus from the merychippus, and the last modern species Equus evolved from Pilohippus.