AN UNUSUAL NEW TRACE FOSSIL FROM THE LOWER CARBONIFEROUS OF IRELAND -INTEXALVICHNUS-MAGNUS

Intexalvichnus magnus, new ichnogenus and ichnospecies, is erected for material from the Lower Carboniferous of northwest Ireland. This ichn ogenus is characterized by a horizontal primary basal gallery, from wh ich a series of secondary near-vertical shafts originate on either sid e of the gallery. Intexalvichnus magnus is typified by vertical shafts occurring in offset closely packed pairs on either side of the horizo ntal gallery, and by their recurved conical morphology. Such material somewhat resembles Phycodes, and in particular ''Phycodes'' pedum, alt hough overall morphology and mode of construction distinguish I. magnu s from Phycodes (including ''P.'' pedum), warranting separate ichnogen eric status. Although forming monospecific associations, I. magnus occ urs within shallow-water deltaic sand-dominated facies with diverse ic hnofaunal assemblages. Consideration of ichnofaunas from similar shall ow-water paleoenvironments suggests that I. magnus should be globally and stratigraphically widespread. Perhaps because of its relatively la rge size I. magnus has been overlooked, or referred to other ichnogene ra.