The Peronopsidae are considered to be the earliest family of the Agnostina. This implicates that the earliest Peronopsid genus (
Archaeagnostus) probably descended directly from the
Eodiscoid genus
Tannudiscus (
Weymouthiidae). Some scholars do not consider the Agnostina true trilobites, and consequently rejected the idea that they were related to the Eodiscina.
Relations within the Peronopsidae Many lineages are thought to have evolved within the Peronopsidae, six of which gave rise to later Agnostina families. •
Archaeagnostus developed into
Pentagnostus, which sprouted the
Ptychagnostidae family early on, and also developed into the advanced subgenus
Pentagnostus (Meragnostus).
Archaeagnostus also developed into the effaced genus
Eoagnostus.
Archaeagnostus is finally the ancestor of the subgenus
Peronopsis (Peronopsis). • The early nominate subgenus of
Peronopsis gave rise to the genera
Quadragnostus and
Diplorrhina, either of which developed into
Gratagnostus. •
Peronopsis (Peronopsis) contains the ancestor of
Iniospheniscus. •
Peronopsis (Peronopsis) fathered the subgenus
Peronopsis (Svenax), which early on sprouted the genus
Redeagnostus, itself the ancestor of the
Agnostidae family. Later
Peronopsis (Svenax) probably developed into
Itagnostus, which is transitional to the
Doryagnostidae family. •
Peronopsis (Peronopsis) brought forth the subgenus
Peronopsis (Vulgagnostus), itself the ancestor of
Baltagnostus from which the
Ammagnostidae descended. The effaced genus
Eoagnostus also descends from
Peronopsis (Vulgagnostus). • A further lineage from
Peronopsis (Peronopsis) includes
Peronopsis (Proacadagnostus),
Acadagnostus, and
Pseudoperonopsis, the earliest genus of the
Diplagnostidae family. •
Peronopsis palmadon is transitional to the
Condylopygoidea superfamily.
Genera previously assigned to the Peronopsidae •
Connagnostus is reassigned to the
Agnostidae •
Euagnostus is reassigned to the
Doryagnostidae •
Pseudoperonopsis is reassigned to the
Diplagnostidae == Description ==