<u>The difference between dog and horse teeth are as follows:</u>
The dental formula of dog is 2 (I3/I3, C1/C1, P4/P4, M2/M3), whereas for the horse it is 2 (I3/I3, C1/C1, P4/P4, M3/M3).
The total number of teeth in the dog is 42, whereas in the case of the horse it ranges from 40 to 42.
In the the dog, upper jaw has 2 molar teeth, whereas in the case of the horse, the upper jaw has 3 molar teeth.
<u>The similarities between dog and horse teeth are as follows:</u>
The most notable similarity in the case of both the animals is that they have the same number of Incisor, Canine, and Premolar in the order of 3, 1, and 4 respectively.
The early atmosphere was mainly carbon dioxide and water vapour. Water vapour condensed to form the oceans. Photosynthesis caused the amount of carbon dioxide to decrease and oxygen to increase.