Definition of Heterostracans. Meaning of Heterostracans. Synonyms of Heterostracans

- Devonian. The heterostracans differed from other Paleozoic agnathan taxa both in the arrangement and histology of their scales. Most heterostracans had two...
- groups, the more primitive heterostracans and the cephalaspids. The cephalaspids were more advanced than the heterostracans in that they had lateral stabilizers...
- or begin. Some experts regard it as being descended from the basal heterostracans of the Silurian. Haaramo, Mikko (2007). "†Pteraspidomorphi". Mikko's...
- by a small fin web. This tail structure clearly differs from that of heterostracans, which are currently grouped with arandaspids and astraspids in the...
- ventral plate forming the edges of the mouth suggest that pteraspidiform heterostracans were filter-feeders that selectively filtered specific sized plankton...
- skeleton, they were first regarded as heterostracans. Now, we know that they are widely different from heterostracans, in particular in retaining about ten...
- Drepanaspis from the Hunsrück lagerstätte. The Psammosteids were the only heterostracans that survived the Upper Frasnian extinction event during the Late Devonian...
- Rhinopteraspis is an extinct genus of pteraspidid heterostracan agnathan. "Rhinopteraspis cornubica (McCoy), with notes on the classification and evolution...
- Protaspis is an extinct genus of pteraspidid heterostracan agnathan which lived during the Early Devonian of the United States, with fossils found in...
- Poraspis is an extinct genus of heterostracan. Fossils are found in Late Silurian and Early Devonian marine strata of Norway, Canada and the United States...