Anaspida

Anaspida is an extinct group of jawless vertebrates known mainly from the Silurian and Devonian. Its members had streamlined bodies covered in small scales rather than heavy armor.

Connect

Jawless fish: Jawless fish are vertebrates that lack hinged jaws, including living lampreys and extinct groups. Anaspids belong to the diverse extinct jawless vertebrates.
Birkenia: Birkenia is a genus of small Silurian anaspids known from Scotland and other localities. Its well-preserved body outlines illustrate the streamlined anaspid form.
Fish scales: Fish scales are dermal structures that protect the body and vary widely in material and arrangement. Small scales, rather than a continuous heavy shield, covered anaspid bodies.
Vertebrate paleontology: Vertebrate paleontology studies the evolution and fossil record of vertebrates. Anaspid identity is inferred from incomplete fossil anatomy.
Ostracoderm: Ostracoderms are extinct jawless vertebrates, many of which bore extensive bony armor. Anaspids were historically grouped among these diverse armored jawless vertebrates.
Lasanius: Lasanius is a genus of Silurian jawless vertebrates with an unusual, lightly mineralized skeleton. Its uncertain anatomy exposes problems in classifying early anaspid-like fossils.
Hydrodynamics: Hydrodynamics is the study of how fluids move and exert forces on bodies. Anaspids' streamlined outlines are relevant to movement through water.
Phylogenetics: Phylogenetics reconstructs evolutionary relationships among organisms or groups. Different interpretations of anaspid traits can change their inferred position.
Vertebrate: A vertebrate is an animal with a vertebral column or its evolutionary precursor. Anaspids occupy an early branch of vertebrate evolution.
Rhyncholepis: Rhyncholepis is an extinct genus of Silurian anaspid vertebrates. It is among the fossil genera used to document anaspid diversity.