This phenotype is hypothesized to have evolved due to a decrease in the proportional size of the tracheal system, which may have been facilitated by elevated oxygen levels. For 10 points each:
[10h] Describe this phenotype displayed prominently by the ground-dwelling genus Arthropleura and the aerial apex predator Meganeura.
ANSWER: arthropod gigantism [accept deep sea gigantism; accept colloquial answers such as “big bugs”]
[10e] The aforementioned spike in arthropod size occurred during this geologic period. Arthropod size declined after this period’s rainforest collapse, which resulted in the formation of most of today’s coal deposits.
ANSWER: Carboniferous [accept Mississipian; accept Pennsylvanian]
[10m] Reptiles generally fared better than giant insects after the Carboniferous rainforest collapse due to their ability to lay this type of land-adapted, hard-shelled egg. This type of egg names the clade that includes reptiles, birds, and mammals.
ANSWER: amniotic eggs [or amniote eggs; accept Amniota]
<Biology>