A systematic revision ofSelenopeltis (Trilobita: Odontopleuridae) with description of new material from the Ordovician Anti Atlas region, Morocco.

The name of the spinose odontopleurid trilobiteSelenopeltisHawle & Corda, 1847, has been given to a characteristic endemic fauna inhabiting the shallow Ordovician seas around the northern margin of Gondwana. First described in detail byJoachim Barrande (1852) from Bohemia, the genus has since been identified from species in Ordovician strata in South Wales, Shropshire, Brittany, the Montagne Noire, Spain, Portugal and ?Iraq. This paper describes new material from the Anti Atlas Region of Morocco. Together with new material from Bohemia and Spain, a general description of the genus is given including details of the hypostoma illustrated for the first time in approximate position beneath the cephalon. Reliable and meaningful criteria for distinguishing the various species assigned to theSelenopeltis buchi group are lacking and there appears to be a gradual series from the earliestS. cf.buchi from the early Llanvirn of South Wales to the CaradocS. buchi from the Welsh Borderland, Bohemia and Morocco.S. macrophthalma (Klouček, 1916) could well be the forerunner ofS. buchi which gave rise toS. vultuosaPřibyl & Vaněk, 1966 during the Caradoc of Morocco and here this species extends into the Ashgill. In BohemiaS. vultuosa is restricted to this time interval.LanguedopeltisPillet, 1988 (type speciesS. binodosusDean, 1966) is considered a synonym ofSelenopeltis. [ABSTRACT FROM AUTHOR]