Dquestion 10 0.34 pts how long does a vertebrate species tend to appear in the fossil record? 10 billion years o 1 billion years o 10 years 1 million years 100 million years d question 11 0.33 pts why does the discovery of an iridium-rich layer at the end of the an asteroid strike was likely the cause of the cretaceous extinction? cretaceous show that iridium is common in the banded iron formations iridium iis very radioactive, with a half-life of 1 day asteroids are rich in iridium, but the crust of the earth is not ridium is an organism that forms in impacts volcanoes spew a lot of iridium when they erupt d | question 12 0.33 pts which of the following is evidence that land animals evolved from aquatic organisms? embryos of land animals develop in a wet environment all of the other answers are correct fertilization in animals always happens in a wet environment concentration of salt in seawater is the same as the concentration in blood proportions of potassium, sodium, and chloride in animal tissues is similer to the in the ocean