Answer:
The answer is A
Explanation:
You can tell that rocks are older or younger depending on if other layers overlap. B is the oldest because all the others cover it, C is the second youngest because D and A overlap it. From what I could tell, when I took the test, it was either A or D, neither overlap each other so I was not sure so I guessed A and got it right. Though it could be looked at that A is smaller than D since its still growing and building.
<span>
1 = Birds, 2 = Mammals, 3 = Amphibians.
I took the test
</span>
There are multiple characteristic that all dinosaurs shared. Some of the synapomorphies include:
- Vertebrates; skeletons with back bones that surrounds a nerve cord.
- Amniotes; specially adapted for life on dry land.
- Diapsids; two holes located above and behind the eye sockets on each side of the skull.
- Archosaurs; antrobital ferestra, a hole between the nasal hole and the eye socket hole.
But still all of this doesn't separate them from all others, what is unique to them is that all of the 'true dinosaurs' were land dwellers.