88


Journal of Paleontology 90(1):78–91


Type species.—Oneotodus? beckmanni Bischoff and Sannemann, 1958.


Pseudooneotodus beckmanni (Bischoff and Sannemann, 1958) Figure 3.9


1984 Pseudooneotodus beckmanni; Idris, pl. 1, fig. 21.


1958 Oneotodus? beckmanni Bischoff and Sannemann, p. 98, pl. 15, figs. 22–25.


1999 Pseudooneotodus beckmanni; Sarmiento et al., p. 760, fig. 3.11.


2007 Pseudooneotodus beckmanni; Corradini, p. 142, pl. 1, figs. 1–7 (see for synonymy).


2007a Pseudooneotodus beckmanni; Zhang and Barnes, fig. 10.5.


2009 Pseudooneotodus beckmanni; Berkyová, fig. 10A–D. 2009 Pseudooneotodus beckmanni; Corradini et al., fig. 3d.


2007b Pseudooneotodus beckmanni; Zhang and Barnes, fig. 10.29.


2009 Pseudooneotodus beckmanni; Corriga and Corradini, fig. 6D, E.


2010 Pseudooneotodus beckmanni; Corradini and Corriga, pl. 1, fig. 21.


2010 Pseudooneotodus beckmanni; Wang and Aldridge, p. 32, pl. 2, figs. 19–26.


2011 Pseudooneotodus beckmanni; Corriga et al., fig. 5.12. 2011 Pseudooneotodus beckmanni; Zhang, fig. 17.7. 2011 Pseudooneotodus beckmanni; Zhang et al., fig. 13.9. 2012 Pseudooneotodus beckmanni; Corriga et al., fig. 5.4.


2013 Pseudooneotodus beckmanni; Zhang, fig. 10.16. 2014 Pseudooneotodus beckmanni; Corriga et al., fig. 5L.


2012 Pseudooneotodus beckmanni; Slavík and Carls, fig. 3U, DD.


2014 Pseudooneotodus beckmanni; Gutiérrez-Marco et al., fig. 5b, c.


2014 Pseudooneotodus beckmanni; Zhang and Pell, fig. 6.8.


Holotype.—Oneotodus? beckmanni, BiSa 1958/85 (Bischoff and Sannemann, 1958, pl. 15, fig. 25).


Occurrence.—Globally occurring; long ranging from Upper Ordovician to Lower Devonian (Corradini, 2007).


Description.—Pseudooneotodus beckmanni is a stout conical element with a single-tipped apex that curves posteriorly. Aboral surface is deeply excavated. The basal outline has been shown to vary, ranging from circular, oval, or subtriangular to other forms (Cooper, 1977).


Remarks.—For a discussion of the taxon, refer to Corradini (2007).


Family Spathognathodontidae Hass, 1959 Genus Ozarkodina Branson and Mehl, 1933a


Type species.—Ozarkodina typica Branson and Mehl, 1933a.


Ozarkodina hassi (Pollock, Rexroad, and Nicoll, 1970) Figure 3.26–3.28


1970 Spathognathodus hassi Pollock, Rexroad, and Nicoll, p. 760, pl. 111, figs. 8–12.


1991 Ozarkodina hassi; Leatham, pl. III, figs. 3, 6, 7, 10, 13, 16, 18, 21.


2002 Ozarkodina hassi; Aldridge, pl. 4, fig. 1. 2002 Ozarkodina hassi; Zhang and Barnes, p. 28, fig. 13.31– 13.37 (see for synonymy).


2012 Ozarkodina hassi; Bergström et al., fig. 7H, I. 2014 Ozarkodina hassi; Zhang and Pell, fig. 8.5–8.7.


?2010 Ozarkodina aff. hassi;Wang and Aldridge, p. 90, pl. 23, figs. 15–27.


Holotype.—Spathognathodus hassi (P1 element), Indiana University/Indiana Geological Survey 12610, Manitoulin Dolomite, locality 7, sample 2, Manitoulin Island, Ontario, Canada (Pollock et al., 1970, pl. 111, fig. 9).


Occurrence.—Occurs globally within the Distomodus kentuckyensis Zone, spaning the Rhuddanian, and ranging to the upper Aeronian (Aldridge, 1972; Zhang and Barnes, 2002). Bergström et al. (2012) documented a range for O. hassi from the Late Ordovician, across the Ordovician-Silurian boundary, and into the Telychian.


Description.—P1 element: Typically a prominent cusp is present; large specimens can show widening due to overgrowth by denticles (McCracken and Barnes, 1981); specimens have previously been shown to lack a prominent cusp (e.g., Nowlan et al., 1988, p. 17, pl. 5, fig. 18). Denticles are laterally com- pressed and almost entirely fused to the apices; anterior denticles are slightly longer and thinner than posterior denticles, and tend to incline anteriorly on the anterior end. Basal cavity flares laterally under the cusp, and is slightly asymmetrical and rounded in oral view, although in aboral view tapers anteriorly and pos- teriorly where it meets the basal margin (Pollock et al., 1970). P2 element: Cusp is high and wide compared to denticles,


and width can increase by overgrowth of short proximal denticles. Denticles gradually decrease in height away from the cusp, and are laterally compressed and almost entirely fused except for the triangular apices. Posterior denticles are significantly shorter than anterior denticles. Posterior process, bearing fewer denticles, is shorter than the anterior process. Basal cavity flares laterally under the cusp and extends as a shallow groove under the processes. Aboral margin is typically straight, but can be slightly arched (McCracken and Barnes, 1981; Cooper, 1975). Cusp and denticles incline posteriorly. Some specimens vary from this description in that they have a longer posterior process with more denticles than the anterior process (Fig. 3.27).


Ozarkodina sp. Figure 3.25


Remarks.—Three specimens of Ozarkodina sp. were recovered. Elements are bowed downward, with a large central cusp inclined toward the posterior; denticles incline posteriorly, and extend up the sides of the cusp; deeply excavated basal cavity


2003 Ozarkodina hassi; Pyle and Barnes, figs. 14.30, 17.10– 17.14.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108  |  Page 109  |  Page 110  |  Page 111  |  Page 112  |  Page 113  |  Page 114  |  Page 115  |  Page 116  |  Page 117  |  Page 118  |  Page 119  |  Page 120  |  Page 121  |  Page 122  |  Page 123  |  Page 124  |  Page 125  |  Page 126  |  Page 127  |  Page 128  |  Page 129  |  Page 130  |  Page 131  |  Page 132  |  Page 133  |  Page 134  |  Page 135  |  Page 136  |  Page 137  |  Page 138  |  Page 139  |  Page 140  |  Page 141  |  Page 142  |  Page 143  |  Page 144  |  Page 145  |  Page 146  |  Page 147  |  Page 148  |  Page 149  |  Page 150  |  Page 151  |  Page 152  |  Page 153  |  Page 154  |  Page 155  |  Page 156  |  Page 157  |  Page 158  |  Page 159  |  Page 160  |  Page 161  |  Page 162  |  Page 163  |  Page 164  |  Page 165  |  Page 166  |  Page 167  |  Page 168  |  Page 169  |  Page 170  |  Page 171  |  Page 172  |  Page 173  |  Page 174  |  Page 175  |  Page 176  |  Page 177  |  Page 178  |  Page 179  |  Page 180  |  Page 181  |  Page 182  |  Page 183  |  Page 184  |  Page 185  |  Page 186  |  Page 187  |  Page 188