Middle Ordovician to Pennsylvanian
Isorophidae is an extinct family of stationary low-level epifaunal suspension feeders
Description of the Family
- Theca domed
- 4 primary orals
- Ambulacral coverplates forming alternatint multiple biseries
- Most small to moderate size, being 10-20 mm in diameter
- Domal theca; oral area including four primary orals, two pairs of laterally shared coverplates, one large hydropore oral, and secondary orals; hydropore structure having few plates, integrated with central oral rise; ambulacral coverplates forming alternating multiple biseries; interambulacrals squamose and imbricate.
- Most Isorophidae are small to moderate-sized edrioasteroids, 10 to 20 mm being common adult diameters.