How To Use Agnathan In A Sentence

Modern vertebrates are classified into two major groups, the gnathostomes (jawed vertebrates) and the agnathans (jawless vertebrates).
Notochords are the axial skeleton of invertebrate chordates (cephalochordates, appendicularians, and tadpole larvae of ascidians), of agnathan fish, and of amphibian tadpoles.
There is also considerable scope for informed speculation about the feeding mechanisms among the extinct agnathans.
One landmark event in vertebrate evolution was the evolution of jaws from agnathan ancestors, which was followed by the first appearance of the stomach.
Above all, the appearance of diverse chordates and agnathans greatly expands our knowledge of the Cambrian explosion.

Related agnathans with external armour occur widely from the Late Silurian to the Devonian, but they all became extinct before the start of the Carboniferous.
During this period the agnathan and gnathostome fishes, too, gave rise to many distinctive groups: the armoured ostracoderm and placoderms, the bony fishes, and elasmobranchs to populate marine and freshwater environments.
Although a small number of bony fishes have brains of the same relative size as those in agnathans, most bony fishes have considerably larger brains for the same body size.
Agnathans generally have the smallest brains for their body size, with hagfishes having brains that are two to three times larger than lampreys of the same body size.
Prototypic T cell receptor and CD4-like coreceptor are expressed by lymphocytes in the agnathan sea lamprey. Stuck on you, biological Velcro and the evolution of adaptive immunity - The Panda's Thumb
There is also considerable scope for informed speculation about the feeding mechanisms among the extinct agnathans.
Sufficient articulated material exists to show that these animals were agnathans (jawless vertebrates), with a bony exoskeleton, and they appear to have inhabited shallow-marine environments.
Related agnathans with external armour occur widely from the Late Silurian to the Devonian, but they all became extinct before the start of the Carboniferous.