Zoology 10th Edition by Stephen Miller,John Harley

تمرين 10

Members of the phylum Chordata are derived from a common deuterosomate ancestor along with the Echinodermata and Hemichordata.
What important character is shared by deuterostomes (but was lost early in the echinoderm lineage)?
FIGURE 17.1 Evolutionary Relationships of Chordata to Other Animals. This figure shows one interpretation of the relationships of the Chordata to other members of the animal kingdom ( see inside front cover ). The relationships depicted here are based on evidence from developmental and molecular biology. Chordates are placed within the Deuterostomia along with the Echinodermata and Hemichordata. This tunicate, or sea squirt ( Polycarpa aurata ), is an invertebrate chordate that attaches to substrates in marine environments. Note the two siphons for circulating water through a filter-feeding apparatus.