Abstract

This paper presents a phylogenetic analysis of the Asteropyginae Delo, 1935. Sixty-six characters and 39 taxa were employed in a cladistic analysis that produced a single most parsimonious tree that is presented as a hypothesis of asteropyginid relationships. In addition to the phylogeny generated, 11 new genera are diagnosed: Philipsmithiana, Coltraneia, Stummiana, Bellacartwrightia, Deloops, Tolkienia, Braunops, Armorigreenops, Kennacryphaeus, Modellops, and Hallandclarkeops, and 12 new species are described: Philipsmithiana hyfinkeli, P. burtandmimiae, Armorigreenops leoi, Pelitlina smeenki, Bellacartwrightia jennyae, B. whiteleyi, B. phyllocaudata, B. calderonae, Greenops widderensis, G. barberi, G. grabaui, and Kennacryphaeus harrisae. Traditionally, asteropyginine taxa in the Appalachian and Michigan Basins of Eastern North America had been assigned to Greenops Delo, 1935, or Greenops (Neometacanthus) Richter and Richter, 1948. A core of five Eastern North American species - Greenops boothi (Green, 1837), G. widderensis, new species, G. chilmanae Stumm, 1965, G. grabaui, new species, and G. barberi, new species - can still be assigned to Greenops. All other asteropyginine taxa in Eastern North America must be assigned to different genera. Species referable to Neometacanthus Richter and Richter, 1948, may be known from the Illinois Basin of Eastern North America, and a species referable to Tolkienia, new genus, may be known from the Michigan Basin of Eastern North America. The single most parsimonious cladogram was also used to investigate biogeographic patterns. In particular, the number of times that independent lineages of asteropyginines invaded from what are now Europe and North Africa (called Armorica herein) into Eastern North America during the Devonian was ascertained. Phylogenetic analysis suggested that there must have been at least four such invasions, with clades that had primitive European or North African affinities giving rise to Eastern North American taxa, although no species are shared between Armorica and Eastern North America. One of the lineages that invaded Eastern North America subsequently reinvaded Armorica. The timing of these invasions and their relation to overall patterns of faunal evolution in the Middle Devonian of Eastern North America are also discussed. These patterns suggest that the different taxa that make up a fauna often arrive during different time intervals, not all at once.