Can you choose the correct numbered item?

Question

The Cambrian rocks of Greenland, currently under an ice sheet, contain fossils of plants and animals now found in tropical areas.The Cambrian rocks of Greenland, currently under an ice sheet, contain fossils of plants and animals now found in tropical areas.The greatest reason for this surroundings change is that in the Cambrain Period,

1 the polar areas were much warmer.

2 tropical plants and animals of today developed from arctic plants and animals of the Cambrian.

3 the land area that is now Greenland was closer to the boundary between the northern and southern hemispheres during the Cambrian Period.

4 Cambrian of occuring in,or characteristic of the Tropics plants and animals could survive a wider range of climates than tropical plants and animals of today.

Answer 1

3) The land area that is now Greenland was closer to the boundary between the northern and southern hemispheres during the Cambrian Period.

Greenland, during the Cambrian, was a part of the continental margin of the continent Laurentia. Laurentia was located just south of the equator during this period.

This excerpt from http://www.peripatus.gen.nz/paleontology/Cambrian.html should help clafify it:

Major Tectonic Events
The Precambrian supercontinent variously known as Proto-Pangea, Ur-Pangea and Rodinia formed ~1,000 Ma from the amalgamation of three or four pre-existing continents, in an event known as the Grenville Orogeny. Perhaps beginning ~700 Ma, but protracted over many millions of years, Rodinia began breaking up into three major blocks: West Gondwana, East Gondwana, and Laurasia. Subsequently - perhaps ~540 Ma, near the beginning of the Cambrian - West and East Gondwana merged in the mountain-building event known as the Pan-African Orogeny. (After Rogers 1996.)

Land and Sea
Gondwana, comprising much of what is now India, Australia, New Zealand, Antarctica, Africa and South America, was a super-continent stretching from ~35ºN almost to the South Pole.

North America and parts of Scotland were united in the subequatorial continent of Laurentia, surrounded by calm seas allowing the accumulation of extensive limestone deposits in marginal basins. Approximately 505 Ma ago, a mudslide on the western continental margin of Laurentia, in what is now eastern British Columbia, buried the famous Burgess Shale fauna.

Answer 2

The answer is 1. The polar areas were much warmer during the pre-cambrian period.

Answer 3

the answer is 3
if you think back to your earth science classes and remember the the techtonic plates on the crust of the earth move around, and thus the continents move around as well. You may probably remember the word Pangea used for the super continent? This would be why now it is cold, and the is was hot! It moved!

Answer 4

This seems quite simply, but maybe not. I guess number 3?

Answer 5

the answer is 1 (one)