Becuase they were fully aquatic unlike tetrapods today
Answer:I also need help with this, can someone please give us the answer
Explanation:
Answer:
B -> increased industrialization
Explanation:
pollution and fossil fuel burning
Mercator projection, type of map projection introduced in 1569 by Gerardus Mercator. It is often described as a cylindrical projection, but it must be derived mathematically. The meridians are equally spaced parallel vertical lines, and the parallels of latitude are parallel horizontal straight lines that are spaced farther and farther apart as their distance from the Equator increases. This projection is widely used for navigation charts, because any straight line on a Mercator projection map is a line of constant true bearing that enables a navigator to plot a straight-line course. It is less practical for world maps, however, because the scale is distorted; areas farther away from the Equator appear disproportionately large. On a Mercator projection, for example, the landmass of Greenland appears to be greater than that of the continent of South America; in actual area, Greenland is smaller than the Arabian Peninsula.
Troposphere
The troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense. Almost all weather is in this region.
Stratosphere
The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high. The ozone layer, which absorbs and scatters the solar ultraviolet radiation, is in this layer.
Mesosphere
The mesosphere starts just above the stratosphere and extends to 85 kilometers (53 miles) high. Meteors burn up in this layer
Thermosphere
The thermosphere starts just above the mesosphere and extends to 600 kilometers (372 miles) high. Aurora and satellites occur in this layer.
Ionosphere
The ionosphere is an abundant layer of electrons and ionized atoms and molecules that stretches from about 48 kilometers (30 miles) above the surface to the edge of space at about 965 km (600 mi), overlapping into the mesosphere and thermosphere. This dynamic region grows and shrinks based on solar conditions and divides further into the sub-regions: D, E and F; based on what wavelength of solar radiation is absorbed. The ionosphere is a critical link in the chain of Sun-Earth interactions. This region is what makes radio communications possible.
Exosphere
This is the upper limit of our atmosphere. It extends from the top of the thermosphere up to 10,000 km (6,200 mi).
