After Whittington, Chang, Dean, Fortey, Jell, Laurie, Palmer, Repina, Rushton & Shergold, 1997
<==o †Spinagostinae Howell, 1935 [Spinagnostidae Howell, 1937; Cyclopagnostinae Howell, 1937; Hypagnostinae Ivshin, 1953; Euagnostinae Öpik, 1979] |-- vasall `--+-- vasall |-- vasall `-- vasall
Reference(s):
- Whittington, H. B., Chang, W. T., Dean, W. T., Fortey, R. A., Jell, P. A., Laurie, J. R., Palmer, A. R., Repina, L. N., Rushton, A. W. A. & Shergold, J. H., 1997: Systematic Description of the class Trilobita. 331-481.
in Kaesler, R. L., (eds.) 1997: Treatise on Invertebrate Paleontology, Part O, Arthropoda 1, Trilobita, Revisited, vol 1: Introduction, Order Agnostida; Order Redlichiida.
–The Geological Society of America, Inc. and The University of Kansas, Boulder, Colorado & Lawrence, Kansas, 1997, xxiv-530