Definition of Agnathan. Meaning of Agnathan. Synonyms of Agnathan

- embryological data, strongly supports the hypothesis that both groups of living agnathans, hagfishes and lampreys, are more closely related to each other than to...
- Rhinopteraspis is an extinct genus of pteraspidid heterostracan agnathan. "Rhinopteraspis cornubica (McCoy), with notes on the classification and evolution...
- aspís, 'shield') is a possibly monotypic genus of extinct osteostracan agnathan vertebrate. It was a trout-sized detritivorous fish that lived in the early...
- of the first reptiles include modern reptiles, mammals and birds; the agnathans have given rise to the jawed vertebrates; the bony fishes have given rise...
- the extant hagfish, and this group may have split early on from other agnathans. The earliest jawed vertebrates probably developed during the late Ordovician...
- Diplograptina making their appearance. One of the earliest known armoured agnathan ("ostracoderm") vertebrates, Arandaspis, dates from the Middle Ordovician...
- 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...
- Pteraspidiformes is an extinct order of heterostracan agnathan vertebrates known from extensive fossil remains primarily from Early Devonian strata of...
- androgen receptor first appeared in gnathostomes (jawed vertebrates). Agnathans (jawless vertebrates) such as lampreys do not produce testosterone but...
- then gave way to the Givetian at 387.95 Ma. During this time, the jawless agnathan fishes began to decline in diversity in freshwater and marine environments...