DBQ: Classifying Cartilaginous Fish
1a. Three orders are needed to classify the eight species of fish. One order for fish with fins wider than long (4 species), and another order for fish with a thin body and compact fins (3). The last order is for the fish that is medium size and proportionately wide to its length.
1b. In the order of the wide-body fish, there could be a range of 1-4 families. There can be one family for flexible tails, or four families with different characteristics on the body. In the order of the thin-body fish, there could also be 1-3 families. There can be one family that envelopes all species for the presence of eyes, or three families with different characteristics on the body.
2. The species in a different order from all the others is the medium-sized fish that has the same width as its length. This is because it clearly is distinct in shape from the rest of the species.
3a. Most likely the rays, or the fish that have a body that is wider than its length and has a flexible tail.
3b. The features of the genus will include the homologous structures of a flexible tail and a body wider than its length.