Oligocarpia?

[paleoflor]

Hi all,

The specimen below comes from the Asturian (Westphalian D) of the Piesberg quarry near Osnabrück, Germany. It has been in my collection for some years already, but I never managed to ID it further than "something with Sphenopteris-like pinnules". Recently, I bought some new literature and now I think I have some sort of ID, but am definitely stuck on the species level (and hence also not quite sure yet about the generic level.)

The specimen from the Piesberg shows a strong resemblance to Oligocarpia gutbierii Göppert 1841 as figured by Kidston (1923), Plate LXX figs. 1-3. Both the presence and the specific appearance of the aphlebia on my specimen (encircled in light blue) also correspond well with Kidston's description text, as well as the aforementioned figures. By contrast, the Oligocarpia gutbierii specimens figured by Kidston (1923) on Plate LXXV, figs 1-2 do not look like my specimen at all (this may be related to them coming from another position in the larger frond - not clear to me.) The specimens figured by Kidston (1923) under Oligocarpia brongniartii Stur 1883 (Plate LXIX, figs 2-3) show less resemblance to the Piesberg specimen. However, in literature dealing with the Piesberg locality, only this species is mentioned to occur (e.g. Josten, 1991). Comparing my specimen to Oligocarpia gutbierii and Oligocarpia brongniartii as figured by Brousmiche (1983), i.e. Plates 57-61 and Plates 62-64, respectively, neither seems to be a very good match. Unfortunately, my French is not good enough to recognise the subtle differences that may be described in the accompanying text volume. Moreover, my specimen is a sterile frond, rendering the most clearly defined differences between Oligocarpia gutbierii and Oligocarpia brongiartii unusable. The venation is difficult to photograph and see, due to gümbelite mineralisation (orange colour), but visible when the specimen is held at an angle to a light source.

Under these constraints, what would be the best way to discriminate between these two (and perhaps other) species? Or am I dealing with something else completely?

Thanks,

Tim

[ZiggieCie]

Very nice Fern.

[paleoflor]

Very nice Fern.

Thanks! Maybe I should just put that on the specimen ID card...

[ckmerlin]

Hi Tim this is indeed an intersting problem especially since as you say your specimen is a sterile frond. The only refernce material i can find is this (see link below) but im afraid it may not be of much use , but hopefully it will give you some new leads or at least be intersting reading for you

http://www.researchgate.net/publication/263887595_Oligocarpia_lindsaeoides_(Ettingshausen)_Stur_and_its_spores_from_the_Westphalian_of_Central_Bohemia_(Czech_Republic)

edit : I just found this also http://www.amjbot.org/content/96/2/475.full

best regards

Chris

Edited August 8, 2015 by ckmerlin

[paleoflor]

Hi Chris,

Thanks for the links; I didn't have the Czech one yet.

Tim

[Plantguy]

Hi Tim, beautiful plant specimen! I unfortunately cant help....I'm just not smart enough. If Chris' links/help dont resolve it I suggest shooting your photos to Dr. Psenicka or Dr. Cleal and I bet they might help sort thru it. PM me if you need any help with that.

Thanks for showing that beauty. Congrats!

Regards, Chris

[ckmerlin]

Hi Chris,

Thanks for the links; I didn't have the Czech one yet.

Tim

My pleasure Tim

best regards

Chris

[paleoflor]

Hi Chris,

Thanks for the suggestion. I emailed Dr. Cleal (yet another Chris) and will report back here when I get a reply.

Kind regards,

Tim