Bransonella? lingulata Ivanov and Ginter, 1996
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publication ID |
https://doi.org/ 10.4202/app.2008.0051 |
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persistent identifier |
https://treatment.plazi.org/id/03802969-223F-8057-AE53-76E3FD9F9D3E |
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treatment provided by |
Felipe |
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scientific name |
Bransonella? lingulata Ivanov and Ginter, 1996 |
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Bransonella? lingulata Ivanov and Ginter, 1996
Fig. 18A View Fig .
Material.—Single tooth, UAPL 23510.
Description.—Base wider (l−l) than long (am−pl; Table 2); lingual margin bifurcated ( Fig. 18A View Fig 1 View Fig ); basal tubercle round with prominent labial rim with no distinct lingual margin; apical button slightly isolated from principal cusps but in contact with intermediate cusp, oval shape ( Fig. 18A View Fig 1 View Fig ), labio−lingually elongated with slightly bifurcated lingual margin ( Table 2); prominent aboral foramen at labial end of groove associated with lingual bifurcation plus about six smaller but significant foramina; significant oral foramina absent. Principal cusps with distal tips missing, approximately equal in size with posterior cusp (left side in Fig. 18 A View Fig 1 View Fig ) possibly longer if cusps restored; both compressed, forming a transverse axis ( Table 2); posterior cusp with at least three cristae on labial side ( Fig. 18A View Fig 2 View Fig ), one of which curves down along posterior margin, some with a tendency to proximally bifurcate onto base, and three on lingual side ( Fig. 18A View Fig 1 View Fig ); anterior cusp with two labial cristae, one of which bifurcates onto base, and possibly four on lingual side. Single intermediate cusp, distal 1/3 missing, antero−posteriorly compressed throughout, with labial, lingual, and marginal cristae ( Table 2), leans posteriorly ( Fig. 18 A View Fig 1 View Fig ), probably 2/3 length of posterior principal cusp. Distinct groove between crown and base on labial side ( Fig. 18A View Fig 2 View Fig ) extends onto anterior and posterior margins.
Remarks.—The attitude of the three cusps suggests UAPL 23510 was in a posterolateral position in the dental arcade. This tooth may belong to Bransonella lingulata , as the apical button extends to the lingual margin of the base (also similar to B. tridentata, Johnson 1984 , although the apical button is not in contact with the intermediate cusp in that species). Its identity is questioned because of the presence of a bifurcated lingual margin; but the aboral lingual groove is similar to fig. 3H in Ivanov and Ginter (1996), although it may also be present in B. nebraskensis ( Johnson 1984: fig. 10a). The shape of the apical button ( Fig. 18 A View Fig 1 View Fig ) is similar to one illustrated by Ivanov and Ginter (1996: fig. 4I), and is quite unlike that in B. nebraskensis ( Johnson 1984; Ivanov and Ginter 1996), although there is considerable overlap in shape between the two species ( Ivanov and Ginter 1996: figs. 1, 3, 4). The greatest difference between UAPL 23510 and B. lingulata is the presence of cristae on the lingual side of the cusps in the former, while they are apparently absent on the lingual side of the latter; however, they are on the edges of the lingual side ( Ivanov and Ginter 1996: fig. 5C; Alexander Ivanov, personal communication, December 2008, claims they are on the lingual side, but certainly not to the extent as seen in UAPL 23510, based on fig. 5C). Cristae sometimes occur on the lingual side in B. nebraskensis ( Johnson 1984: 183; Ivanov and Ginter 1996: fig. 1J), but not as extensively as in UAPL 23510. The intermediate cusp in B. lingulata teeth tends to be shorter than that in UAPL 23510, although it is antero−posteriorly compressed in both, as in B. nebraskensis ( Johnson 1984: 180) . UAPL 23510 could questionably be assigned to B. nebraskensis , but the nature of the apical button prevents this.
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