PROTOSALVINIA DAWSON AND ASSOCIATED CONODONTS OF THE UPPER TRACHYTERA ZONE, FAMENNIAN, UPPER DEVONIAN, IN THE EASTERN UNITED STATES

Journal of Paleontology, Jan 2009 by Over, D Jeffrey, Lazar, Remus, Baird, Gordon C, Schieber, Juergen, Ettensohn, Frank R

SYSTEMATIC PALEONTOLOGY

The higher taxonomic categories of Sweet (1988) and element notation of Purnell et al. (2000) are followed herein. Figured specimens are housed in the Orton Museum at Ohio State University, Columbus, Ohio (OSU). AU other materials are in the collections at SUNY-Geneseo stored by locality.

Class CONODONTI Branson, 1938

Order PRIONIODONTIDA Dzik, 1976

Family ICRIODONTIDAE M�ller and M�ller, 1957

Genus PELEKYSGNATHUS Thomas, 1949

PELEKYSGNATHUS ELLICOTTENSIS new species

Figure 4.6, 4.7, 4.12, 4.13, 4.16-4.20

? Pelekysgnathus cf. P. brevis SANDBERG AND DREESEN, JOHNSTON AND CHATTERTON, 2001, p. 21, pi. 4, figs. 17, 18 [only].

Diagnosis. - P, element: segminate, very short blade, slightly arched and curved, high inclined cusp, single broad, laterally compressed, prominent vertical to anteriorly directed denticle on anterior end of blade; a small low denticle may be developed posterior of the large denticle. Basal cavity extends length of element, two tips in expanded basal cavity beneath cusp. Coniform elements: nongeniculate, erect to proclined, asymmetrical to compressed base, ornamented with fine longitudinal striae.

Etymology. - Named for Ellicott Township, Chautauqua County, New York.

Material examined. - Locality F, H, 9 P1 elements, 5 conical elements.

Types. - Holotype OSU 52959, the specimen illustrated in Figure 4.7 from Little Elk Creek, PA, Locality F; paratypes OSU 52625-OSU 52630 from same location; OSU 52958 from tributary to Clear Creek, Locality H.

Discussion. - Insufficient coniform elements were recovered to reconstruct an apparatus. Large translucent specimens of Pelekysgnathus ellicottensis have numerous small denticle-like features distinguished by white matter within the blade between the cusp and large anterior denticle; yet a small specimen (Fig. 4.6) does not have minor denticles developed. The P^sub 1^ element of Pelekysgnathus ellicottensis has a very short blade that is similar to Pelekysgnathus brevis Sandberg and Dreesen (1984), but the later is characterized by two or three short denticles anterior of the prominent cusp. Johnston and Chatterton (2001) illustrated two small P^sub 1^ elements bearing a prominent cusp and single or no posterior denticles similar to P. ellicottensis from lower Famennian strata of western Canada as P. cf. P. brevis; no coniform elements were described. Pelekysgnathus australis Nicoli and Druce 1979 from the high Famennian of Australia is characterized by coniform elements that are typically striated; the P^sub 1^ element may also have striae on the cusp, but has three to four denticles (Nicoli and Druce, 1979). !Pelekysgnathus guizhouensis as reconstructed by Over (1992), a high Famennian taxon, has coniform elements that have longitudinal striae; the P1 element differs significantly in having numerous denticles on a longer blade.

ACKNOWLEDGEMENTS

Specimens used in this study were collected as part of NSF EAR-9614314 to DJO and by FRE in studies of black shale strata NSF EAR-8513414. Thanks to the donors of the Petroleum Research Fund, administered by the American Chemical Society (Grant #38523-AC8) for financial support; J. Rupp from the Indiana State Survey, P. Gooding and R. Daniel from the Kentucky Geological Survey, and G. Schumacher from the Ohio Geological FIGURE 7 - Digital mirrored inverse SEM images of conodont molds in shale matrix, P^sub 1^,-elements from New Albany Shale Walton 1-12 drill core. Core boxes are numbered, conodont-bearing horizons are shown by horizontal bars and core interval of imaged conodonts is labeled; P = Protosalvinia. Scale bar = 1.0 mm, except figs. 8 and 9 where bar = 0.5 mm. 1, 6, Palmatolepis glabra distorta Branson and Mehl. I, 5-6, OSU 52,986, upper view; 6, 3-14, OSU 52,987, upper view. 2, Palmatolepis perlobata sigmoidea Ziegler. 5-11, OSU 52,988, upper view. 3, Palmatolepis perlobata grossi Ziegler, 5-11, OSU 52,989, upper view. 4, Polygnathus perplexus Thomas, 5-11, OSU 52,991, upper view. 5, Polygnathus brevilaminus Branson and Mehl, 5-11, OSU 52,992, lateral view. 7, Palmatolepis falcata (Helms), 2-12, OSU 52,993, upper view. 8, 9 Palmatolepis glabra angusta �apkinoglu, 2-14, OSU 52,996, OSU 52,997, upper views.