SELECT LOWER AND MIDDLE DEVONIAN PHACOPID TRILOBITES FROM SOUTHERN MOROCCO

Phacopid trilobites are among the most ubiquitous fossils within the Lower and Middle Devonian strata of Morocco, and display a diversity of form seen at no other point in the history of the family. The southern and southeastern margins of Morocco are ideal for studying the Phacopidae through this time interval, because rock units of this age are present in long, continuous exposures that are traceable for many kilometers along strike, only affected by low amplitude folding and minor faulting. Furthermore, the fossils themselves show articulation and preservation matched in few other localities (making complete, definitive descriptions possible), and are commercially mined by the local Berbers (making specimens available in large numbers). This study is of the phacopids, as they occur in correlatable strata from the three major Devonian basins in southern Morocco (the Tindouf, Tafilalt, and Ma'der basins), and shows that their presence is useful for correlation within and between these basins, as well as farther abroad. In the process, 11 new taxa of specific or subspecific rank are described, including a single new species of Reedops, a single new species of Boeckops, and 6 new species/subspecies of Phacops. (Three additional Phacops species from this region have been described recently in Chatterton et al., 2006, including Phacops smoothops, P. granulops, and P. lebesus). New information is also provided for Reedops bronni (Barrande, 1846), R. cephalotes hamlagdadianus Alberti, 1983, Pedinopariops (Hypsipariops) vagabundus Struve, 1990, Drotops megalomanicus megalomanicus Struve, 1990, and D. armatus Struve, 1995. Cladistic analysis of these taxa and other pertinent phacopids suggests the relationships of these taxa, and has implications for their higher-level taxonomic placement. The in-depth study of large numbers of Reedops and Phacops specimens, in a wide range of depositional settings, has also led to some insights into their life-modes, enrollment behaviours, sculpture, and coaptative devices.