Which statement is NOT true about echinoderms?

Mammals appeared and diversified in the Precambrian era.

What is a mental representation?

Which of the following is NOT a shared characteristic of mammals?

The most successful mammals belong to the marsupials group.

Which of the following does NOT describe phylum Ascomycota?

The choanoflagellates are within this supergroup.

This scientist developed the field of paleontology

The first plants to colonize land were the

The ranges of the red-legged frog and the yellow-legged frog overlap in California. The red-legged frog (Rana aurora) breeding season lasts from January to March. The closely related yellow-legged frog (Rana boylii) breeds from late March through May. What type of reproductive isolating mechanism is mainly responsible for keeping these two species separate?