Opinions from J. J. Eberle and J. A. Lillegraven 1998
- 'Alticonus belongs to Periptychidae'
- 'Alticonus gazini belongs to Alticonus'
- 'Ampliconus belongs to Periptychidae'
- 'Ampliconus antoni belongs to Ampliconus'
- 'Ampliconus browni belongs to Ampliconus'
- 'Anisonchus agapetillus is recombined as Oxyacodon agapetillus'
- 'Anisonchus apiculatus is a subjective synonym of Mithrandir gillianus'
- 'Anisonchus apiculatus is a subjective synonym of Mithrandir gillianus' according to Cifelli 1983
- 'Anisonchus cophater is recombined as Conacodon cophater'
- 'Baioconodon middletoni belongs to Baioconodon'
- 'Chriacus antiquus is recombined as Oxyclaenus antiquus'
- 'Chriacus hyattianus is recombined as Loxolophus hyattianus'
- 'Chriacus priscus is recombined as Loxolophus priscus'
- 'Conacodon delphae belongs to Conacodon'
- 'Conacodon harbourae belongs to Conacodon'
- 'Ectoconus cavigellii belongs to Ectoconus'
- 'Ectoconus majusculus is a subjective synonym of Ectoconus ditrigonus'
- 'Fimbrethil is a subjective synonym of Oxyacodon'
- 'Fimbrethil ambaronae is a subjective synonym of Oxyacodon agapetillus'
- 'Gillisonchus is a subjective synonym of Mithrandir'
- 'Gillisonchus is a subjective synonym of Mithrandir' according to Cifelli 1983
- 'Haploconus gillianus is recombined as Mithrandir gillianus'
- 'Haploconus gillianus is recombined as Mithrandir gillianus' according to Cifelli 1983
- 'Loxolophus faulkneri belongs to Loxolophus'
- 'Loxolophus nordicus is recombined as Baioconodon nordicus'
- 'Maiorana ferrisensis belongs to Maiorana'
- 'Mioclaenus cuspidatus is recombined as Oxyclaenus cuspidatus'
- 'Mithrandir belongs to Periptychidae'
- 'Oxyacodon priscilla belongs to Oxyacodon'
- 'Periptychus brabensis is a subjective synonym of Periptychus coarctatus'
- 'Periptychus coarctatus belongs to Periptychus'
- 'Periptychus ditrigonus is recombined as Ectoconus ditrigonus'
- 'Periptychus matthewi is a subjective synonym of Periptychus coarctatus'
- 'Protogonodon is a subjective synonym of Loxolophus'
- 'Protogonodon grangeri is recombined as Loxolophus grangeri'
- 'Ragnarok is a subjective synonym of Baioconodon'
- 'Ragnarok engdahli is recombined as Baioconodon engdahli'
- 'Ragnarok harbichti is a subjective synonym of Baioconodon nordicus'
- 'Ragnarok wovokae is recombined as Baioconodon wovokae'