chordates with a well-defined head region, including a definite brain at the front end of the nerve cord and cranial nerves connected to well-defined sense organs (eyes, nose, ears).

refers to the flexible rod of cartilage, the notochord, along the back that serves for support

one of the best index fossils for the early paleozoic

Is the act or process of drying.

The discovery that birds evolved from small carnivorous dinosaurs of the Late Jurassic was made possible by recently discovered fossils from China, South America and other countries

Found in most primitive ammoniates and in advanced aquatic Mesosaurs. No temporal fenestrae; solid skull roof.

the study of fossil plants.

The largest group of advanced teleosts including about 15,000 living species in 300 families.

popularly refferes to as the "bony fish", is a diverse taxonomic group of fish that have skeletons primarily composed of bone tissue, as supposed to cartilage.

Gnathostomes

gnathos is "jaw" and stoma is "stomach"

are an extinct group of agnathan vertebrates resembling eels, classified in the class Conodonta

They burrow along the seafloor seeking out dead and dying fish and polychaete worms, which they can slurp up faster than a strand of spaghetti.

Garstang (1928) first suggested that neotenic retention of larval characteristics is not important in chordate evolution

had a flattened body with broad pectoral fins like the living skates and rays

had flattened bodies with long bony spines projecting in an arc in front of their pectoral fins

After placoderms and chondrichthyans, the third great group of middle Paleozoic fish was ______.

Synapsids is a single temporal fenestra (high on the skull, above the postorbital-squamosal bones)

"blue-green algae," have left a fossil record that extends far back into the Precambrian

known as tunicate, ascidians or "sea squirts"

True algae are eukaryotic organisms, consisting of cells with a discrete nucleus, and other organelles.