Pristiograptus dubius postfrequens, Urbanek & Radzevičius & Kozłowska & Teller, 2012
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publication ID |
https://doi.org/ 10.4202/app.2010.0070 |
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persistent identifier |
https://treatment.plazi.org/id/892C87DF-9228-FFF7-FF5A-30F6FE6FE714 |
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treatment provided by |
Felipe |
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scientific name |
Pristiograptus dubius postfrequens |
| status |
subsp. nov. |
Pristiograptus dubius postfrequens subsp. nov.
Figs. 6P, 11J, L.
Etymology: From Latin post, after; frequens , frequent.
Holotype: ZPAL G./24, isolated rhabdosome with sicula and thee thecae illustrated in Urbanek 1997: fig. 43D.
Type locality: Mielnik−1 borehole, depth 786.5 m, Poland.
Type horizon: Upper Ludlow, Monograptus (Uncinatograptus) acer Biozone.
Material.—About 50 rhabdosomes and some fragments from Mielnik−1 borehole (915– 690 m), Poland and Milaičiai−103 borehole (1255– 1210 m), Lithuania.
Diagnosis.—Thecal lip ends in the middle or above the free ventral wall of the succeeding theca. Sicula with three rings.
Description.—The rhabdosome is narrow and slightly curved ventrally at the proximal end. The rhabdosome widens gradually from 0.6 mm at th 1, to 0.7 mm at th 2, 0.8 mm at th 3. Interapertural width is 0.5 mm at th 1, 0.6 mm at th 2, 0.7 mm at th 3. There are 10–12 thecae in 10 mm. The ss angle is obtuse. Th 1 is 0.9 mm long and 0.3 mm wide. The free part of each theca is half of its whole length. The end of the thecal lip may continue up to the half length of the free part of succeeding thecae or above. The λ angle is 30 °. Sicula length is 2.2 mm and width is 0.3 mm. The apex of the sicula reaches the base of th 3. There are three sicular rings.
Discussion.— P. dubius postfrequens is similar to P. dubius frequens . The difference is in the number of sicula rings and in the position of the thecal apertural end. P. dubius postfrequens has fixed 3 sicular rings whereas in P. dubius frequents the number of sicular rings vary from 3 to 8. The end of the thecal lip of P. dubius postfrequens may continue up to the half length of the free part of succeeding theca or above, whereas the thecal apertural lip of P. dubius frequens is ending at the beginning of the ventral wall of succeeding theca.
Stratigraphic and geographic range.— Saetograptus leintwardinensis – Monograptus (Uncinatograptus) spineus Biozone , Poland and Lithuania.
| ZPAL |
Zoological Institute of Paleobiology, Polish Academy of Sciences |
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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