Question

dinosaurs become extinct? Cretaceous Examine the strata (layers of rock) in Figure 2.2. Use the information in the geologic time scale to answer the following questions Stratum E-human Stratum B - trilobite - с Stratum A - sea jelly Figure 2.2: Rock strata (from lowest to highest). 1. Which stratum is the oldest? Justify your answer. 2. What is the relative age of stratum B7 Justify your answer. 3. Observe the skulls in strata C&D. One is a dinosaur skull and the other is a primitive amphibien skull. The dinosaur skull is in stratum The primitive amphibian skull is in stratum How did you determine this? 18 Evolutionary Observations Exercise 2

Answer 1

1) Stratum A is the oldest.The formation of stratum is towards upside means a new stratum forms on old stratum.So the youngest one forms on most upper side and the oldest one is at the bottom.

2) This stratum B must be of 500-600 million years old because the trilobites lived between this era and the stratum containing fossils of trilobites must be of this time.

3) The Dinosaur skull is in stratum D

The primitive amphibian skull is in stratum C

a)The primitive amphibians are older than dinosaurs , so if the fossils have been formed then they must be found in lower stratum and b) the dinosaurs had large skull and the fossil diagram can be easily distinguished.