The conodont genus Ctenognathodus in the Silurian of Gotland, Sweden

Abstract: Seven taxa of the conodont genus Ctenognathodus (Fay, 1959) sensu Viira, 1982b in the Silurian of Gotland have been described and their occurrence mapped geographically, stratigraphically and related to facies. In addition to C. murchisoni (Pander, 1856) three new species were found; C. n. sp. D, C n. sp. E and C n. sp. I with two subspecies, I and G. Two taxa formerly known as subspecies of Ligonodina confluens Jeppsson, 1972 were supplemented with previously missing elements and assigned separate species status within Ctenognathodus; C. n. sp. L and C. confluens. The genus spans most of the fossil record of Gotland, but is confined to shallow-water, high-energy carbonate facies. Its members regularly constitute a minor part of the conodont fauna and probably occupied specialized niches, judging by element morphology. Many of the species reappear on various separate levels in the succession. In addition to discussion on functional and palaeoecological aspects, a cladistic scheme is proposed for the taxon Ctenognathodus.