Baltoniodus sp. A
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publication ID |
https://doi.org/ 10.3853/j.0067-1975.55.2003.1383 |
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persistent identifier |
https://treatment.plazi.org/id/37439A20-CB26-FF32-FC29-FBE8FD5CFD8F |
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Felipe |
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Baltoniodus sp. A |
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Fig. 11P–X View Fig
? Baltoniodus navis .– Cooper, 1981: 168, pl. 30, fig. 2.
Material. Thirteen specimens (11 P, 2 M) from the Tabita Formation at Mount Arrowsmith.
Description. Only P and M elements recovered; the P element is pastinate with denticulate anterior and posterior processes, and adenticulate outer lateral process; cusp more or less triangular in cross section ( Fig. 11T,U View Fig ), with sharp anterior and posterior margins, and smooth inner lateral side; the outer lateral face with a broad costa which extends basally into a short adenticulate process; anterior process extending downward with three or four stout denticles; posterior process longer, bearing five to seven stout denticles; basal cavity open, rather deep. M element strongly geniculate, bearing a long anticusp with fine saw tooth-like denticles on its upper margin ( Fig. 11Q,R View Fig ); base of denticles with distinctive surface sculpture ( Fig. 11P View Fig ).
Remarks. The species is assigned to Baltoniodus based on its wide basal cavity and orientation of the anterior and posterior processes essentially in a single plane. The P element of this species differs from those of Oepikodus pincallyensis in having a much smaller cusp, an adenticulate outer lateral process, and a more open basal cavity. The anterior and posterior processes are more or less straight within a single plane, whereas in the P elements of Oepikodus pincallyensis the anterior process is strongly curved inward. The P element described herein is close to the specimen referred to Baltoniodus navis illustrated by Cooper (1981, pl. 30, fig. 2) from the Horn Valley Siltstone. However, that element has a longer posterior process bearing up to nine denticles, which are more widely spaced than in the Mount Arrowsmith material. The originally described P elements of Baltoniodus navis Lindström, 1955 possess long denticulate outer lateral processes which meet the anterior process at an angle of about 30°, whereas the Tabita Formation species has an adenticulate, short outer lateral process, which is almost normal to the anterior and posterior processes; the anterior process is in the same plane with the posterior process ( Fig. 11T,V View Fig ), or only very slightly curved inner laterally ( Fig. 11X View Fig ).
Bergstroemognathus Serpagli, 1974 Type species. Oistodus extensus Graves & Ellison, 1941 .
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Baltoniodus sp. A
| Zhen, Yong Yi, Percival, Ian G. & Webby, Barry D. 2003 |
Baltoniodus navis
| Cooper, B 1981: 168 |