Mazon Concretion Identification Help Requested

[Jones1rocks]

I've gone through the galleries (some of, anyway) of Mazon Creek flora, and have a question on two concretions in my possession. Specimen # 1 resembles]pictures of Lepidostrobus, but I am uncertain.I could not find a photo of anything exactly like specimen #2, but it resembles a Neuropteris leaf with a round object at one end. Is it just another small leaflet?

[prem]

#2 is a Neuropteris leaf partially buried in the matrix, giving it the appearance that a part is sorta pinched off.

I can't help with #1b.

---Prem

[abyssunder]

I'm not a specialist in plants, but I think #2 looks close to Neuropteris hirsuta (Lesquereux), with one compound leaflet. http://www.georgesbasement.com/LesquereuxAtlasP/Lesquereux-Plate08.htm

[snakebite6769]

The first one (#2) reminds me of one of the "helicopter seeds". At least that's what we call them because they spin like a rotor on a helicopter when they fall to the ground. Pretty neat! Neuropteris most likely though.

[Jones1rocks]

Snakebite, we call them maple seeds or 'whirlygigs'. That was my first impression of the fossil, too!

I'm not a specialist in plants, but I think #2 looks close to Neuropteris hirsuta (Lesquereux), with one compound leaflet. http://www.georgesbasement.com/LesquereuxAtlasP/Lesquereux-Plate08.htm

Oh my gosh! Neuropteris hirsuta is a definite maybe, with the 'split' leaf and smaller round leaf, just as in one of the illustrations in the link! Thank you so much!

[Rob Russell]

Specimen 1b may be a poorly preserved essexella jellyfish skirt.

[fiddlehead]

Your #2 is now called Macroneuropteris scheuchzerii. The orbicular pinnule at the base is characteristic to the taxon. M. scheuchzerii is what is known as trifoliate. This is where three lamina make a maturely formed leaf. Mostly just the terminal leaf is found. Think of it like a black walnut leaf, which has a compound leaf with several lamina. The name offered here, Neuropteris hirsuta is a discarded name and a junior synonym of M. scheuchzerii. What happened is Lesquereux erected a name on this form which was validly named 40 years earlier by Hoffman. Lesquereux often missed names erected in Europe and his nomenclature is best taken with a grain of salt. As for the other one, it is to my eye an indeterminate, this is not to say it isn't something, just it will remain a guess till more are found.

Hope that helps,

Jack

[Plantguy]

Nice finds--the Macroneuropteris especially, its one of my favorite plant types from there. I think I can see the little hair-like structures (very small narrow needle like lines) that many of them have on them too...

Regards, Chris

[Jones1rocks]

Your #2 is now called Macroneuropteris scheuchzerii. The orbicular pinnule at the base is characteristic to the taxon. M. scheuchzerii is what is known as trifoliate. This is where three lamina make a maturely formed leaf. Mostly just the terminal leaf is found. Think of it like a black walnut leaf, which has a compound leaf with several lamina. The name offered here, Neuropteris hirsuta is a discarded name and a junior synonym of M. scheuchzerii. What happened is Lesquereux erected a name on this form which was validly named 40 years earlier by Hoffman. Lesquereux often missed names erected in Europe and his nomenclature is best taken with a grain of salt. As for the other one, it is to my eye an indeterminate, this is not to say it isn't something, just it will remain a guess till more are found.

Hope that helps,

Jack

Jack,

Thank you very much for the insight. I had been seeing the Macroneuropteris scheuchzerii photos and wondering if that was it, and your explanation provides the reasoning behind that. Very interesting history behind it all, too!

~Paul