Definition of Agnathans. Meaning of Agnathans. Synonyms of Agnathans

- extinct agnathans sported extensive exoskeletons composed of either m****ive, heavy dermal armour or small mineralized scales. Almost all agnathans, including...
- gnathostomes than to the surviving agnathans, known as cyclostomes. Cyclostomes apparently split from other agnathans before the evolution of dentine and...
- Rhinopteraspis is an extinct genus of pteraspidid heterostracan agnathan. "Rhinopteraspis cornubica (McCoy), with notes on the classification and evolution...
- have evolved as a region distinct from the medulla by the time the first agnathans appeared, 525 million years ago. Location and topography of pons (animation)...
- Myllokunmingiidae is a group of very early, jawless prehistoric fish (Agnathans) which lived during the Cambrian period. The Myllokunmingiids are the...
- Diplograptina making their appearance. One of the earliest known armoured agnathan ("ostracoderm") vertebrates, Arandaspis, dates from the Middle Ordovician...
- A blind fish is a fish without functional eyes. Most blind fish species are found in dark habitats such as the deep ocean, deep river channels and underground...
- Archipelepis is a genus of extinct thelodont agnathans, and are the most primitive recognized thelodonts of which whole body fossils are known. Fossils...
- Late Silurian of Canada, Norway, and the U.S. Tujiaaspis is a galeaspid agnathan from the early Silurian (Telychian) of China, showing origin of paired...
- developed medulla oblongata. Since these are both very similar to early agnathans, it has been suggested that the medulla evolved in these early fish, approximately...