Pentagnostus is a genus of small, blind, agnostid trilobites restricted to the Middle Cambrian. Its remains have been found in Siberia, Australia, North America, Scandinavia, and Kazakhstan.
Taxonomy
The probable ancestor of Pentagnostus is Archaeagnostus. Two subgenera can be distinguished. The nominate subgenus occurred first and developed into the later subgenus Pentagnostus (Meragnostus) and the family Ptychagnostidae.
Species and distribution
Subgenus Pentagnostus (Pentagnostus)
- P. anabarensis (<small>Lermontova, 1940) (type)</small>
- P. ademptus <small>(Prokovskaya and Jegorova, 1972)</small>
- P. brighamensis <small>(Resser, 1938)</small>
- P. shergouldi (<small>Laurie, 2004)</small>
- P. veles (<small>ÃÂpik, 1979)</small> synonym P. endemicus.
- P. praecurrens (WestergÃÂ¥rd, 1936)
Subgenus Pentagnostus (Meragnostus)
- P. bonnerensis <small>(Resser, 1939) (type)</small> synonyms P. admirabilis and Agnostus lautus.
- P. bulkurensis <small>(Prokovskaya and Pregel, 1982)</small>
- P. remotus <small>(Prokovskaya and Jegorova, 1969)</small>
- P. segmentus <small>(Robison, 1964)</small>
- P. shabactensis <small>Ergaliev, 2008</small> synonym Peronopsis ultima <small>Ergaliev, 1980 non Poulsen 1960</small>.
References