Kirkigraptus inexpectans, Kozłowska & Bates, 2008
|
publication ID |
https://doi.org/ 10.4202/app.2008.0107 |
|
persistent identifier |
https://treatment.plazi.org/id/03C90769-F46A-183E-FCCD-62605680F48F |
|
treatment provided by |
Felipe |
|
scientific name |
Kirkigraptus inexpectans |
| status |
sp. nov. |
Kirkigraptus inexpectans sp. nov.
Figs. 3 View Fig , 4 View Fig .
Derivation of the name: Inexpectans—after Latin inexpectus, not expected.
Holotype: ZPAL G. 40/01, well preserved specimen with proximal end, Fig. 3A View Fig .
Material.— Three specimens (two of them with complete proximal end, Fig. 3A, C View Fig ; and one with partly preserved proximal end, Fig. 3F View Fig ) from Bartoszyce depth 1598.0 m; five specimens without proximal end from depth 1599.2 m, eight fragments from depth 1599.6 m. Other graptolites: depth 1598.0 m: Neogothograptus thorsteinssoni Lenz and Kozłowska−Dawidziuk, 2001 , Pristiograptus dubius ( Suess, 1851) , Saetograptus chimaera Barrande, 1850 ; depth 1599.2 m: Neodiversograptus nilssoni Lapworth, 1876 , Pristiograptus dubius , S. chimaera , Spinograptus spinosus Eisenack, 1951 ; depth 1599.6 m: Spinograptus spinosus , P. ludensis ( Murchison, 1839) .
Diagnosis.—As for the genus.
Description.—The best preserved specimen (ZPAL G. 40/01) represents the proximal end and two rows of thecae: the first thecal row with two thecae, the second row with three thecae. Distance between thecal walls proximally is 2.1 mm. The distal part of the rhabdosome, represented by a fragment with four distal thecae (ZPAL G. 40/02, Fig. 3B View Fig ), tapers to a width between thecal walls of about 1.5 mm. The mid−ventral lists are convex and longer than the lateral apertural rods ( Fig. 3 View Fig ). The ventral panels of lists (apertural and pleural lists) are straight. The lateral apertural lists increase in length distally, from 0.35 mm for the most proximal, to 0.7 mm for the most distal ones. The first pleural lists are about 0.35 mm in length, but succeeding lists are about 0.28 mm in length ( Fig. 3 View Fig ).
The first horizontal ancora sleeve list appears at the level of theca 32, about 2 mm from the proximal end of the rhabdosome. Subsequent lists are spaced at 1.6 mm intervals (ZPAL G. 40/07, Fig. 3G View Fig ).
KOZŁOWSKA AND BATES— KIRKIGRAPTUS NEW GRAPTOLITE FROM POLAND 111
Discussion.—Because of the limited number of specimens, and their position on the SEM stubs, it is difficult to ascertain some of the detail of branchings and seams. Hence it is difficult to reconstruct the form of the ancora umbrella, if it existed. An attempt at reconstruction is presented in Fig. 2A View Fig . The form of the proxi−lateral lists is shown in Figs. 4B View Fig 3 View Fig , F 1 View Fig , F 2 View Fig , and 5, the seams present are largely hidden.
Two of the specimens show what may be abnormalities. Specimen 302A ( Fig. 3B View Fig ) shows the growing distal end with the last thecal orifice not finished. The right hand side lists of the orifice are normal in size whereas the left hand side lists are thin, with a short list which might be a beginning of the growing genicular list on the lateral apertural rod. The last ancora sleeve list on the nearer side runs obliquely, from a junction with a horizontal sleeve list, to join the pleural list. The first orifice in the ventral wall of specimen ZPAL G. 40/04 ( Fig. 3D View Fig ) is much smaller than the other orifices and has a different shape, being rounded especially in its proximal part. The position and shape of the orifice make it similar to the pre−theca 11 orifice in Plectograptus mobergi Bates, Kozłowska, Maletz, Kirk, and Lenz, 2006 ( Fig. 1 View Fig ). Such an orifice is not observed in the best preserved specimen ( Fig. 3A View Fig ) but its possibility of preservation is marked in the reconstruction of the new form on Fig. 2 View Fig .
The pustular ornament, as is typical of Plectograptinae , is largely on the outer sides of the lists. An unusual feature is that ornament with pustules of two different sizes is present ( Fig. 4D View Fig 2 View Fig ).
Stratigraphic and geographic range.—As for the genus.
| 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.