- Psammosteidae
Taxobox
name = "Psammosteidae"
status = fossil
image_caption = "Drepanaspis gemuendina" and "Tiaraspis subtilis"
fossil_range = Early to LateDevonian
regnum =Animal ia
classis =Agnatha
ordo =Heterostraci
familia = Psammosteidae
subdivision_ranks = Genera
subdivision =
* "Drepanaspis "
* "Pycnosteus "
* "Psammolepis "
* "Schizosteus "
* "Tartuosteus "The Psammosteidae are a family of flattened, benthic jawlessvertebrate s that lived in marine andestuary environments in Europe, Russia & North America. They arose during theEarly Devonian , with the first (and best) known genus, "Drepanaspis " from theHunsrück lagerstätte . The Psammosteids were the only heterostracans that survived the UpperFrasnian extinction event during theLate Devonian , dying out in the extinction event at the very end of the Devonian.Many of the Late Devonian genera, such as "Psammolepis", were among the largest heterostracans ever, growing to be at least 1.5
metre s in width.References
* [http://www.palaeos.com/Vertebrates/Units/040Pteraspidomorphi/040.800.html#Psammosteida "Palaeos Vertebrates"]
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