Pentagnostus

Pentagnostus Temporal range: Middle Cambrian PreꞒ Ꞓ O S D C P T J K Pg N
Pentagnostus brighamensis, 6mm, Spence Formation
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Clade:	† Artiopoda
Class:	† Trilobita (?)
Order:	† Agnostida
Family:	† Peronopsidae
Genus:	† Pentagnostus Lermontova, 1940
subgenera
Pentagnostus (Pentagnostus) Pentagnostus (Meragnostus)Naimark, 2012 and see text for species [1]

Pentagnostus is a genus of trilobites restricted to the Middle Cambrian. Its remains have been found in Siberia, Australia, North America, Scandinavia, and Kazakhstan. ^[1]

Taxonomy

Schematic showing the relationship between both subgenera of Pentagnostus (light green), the ancestral Archaeagnostus (darker green) and the descending Ptychagnostidae (red). Based on E. B. Naimark (2012). Hundred species of the genus Peronopsis Hawle et Corda, 1847. Paleontological Journal 46(9):945-1057

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. ^[1]

Species and distribution

Subgenus Pentagnostus (Pentagnostus)

• P. anabarensisLermontova, 1940 (type)
• P. ademptus(Prokovskaya and Jegorova, 1972)
• P. brighamensis(Resser, 1938)
• P. shergouldiLaurie, 2004
• P. velesÖpik, 1979 synonym P. endemicus. ^[1]

Subgenus Pentagnostus (Meragnostus)

• P. bonnerensis(Resser, 1939) (type) synonyms P. admirabilis and Agnostus lautus.
• P. bulkurensis(Prokovskaya and Pregel, 1982)
• P. remotus(Prokovskaya and Jegorova, 1969)
• P. segmentus(Robison, 1964)
• P. shabactensisErgaliev, 2008 synonym Peronopsis ultimaErgaliev, 1980 non Poulsen 1960. ^[1]

References

1. Naimark, E.B. (2012). "Hundred species of the Genus Peronopsis Hawle et Corda, 1847". Paleontological Journal. 46 (9): 945–1057. Bibcode:2012PalJ...46..945N. doi:10.1134/S0031030112090018. S2CID   85130465.