Hello Sven..
Your species of Pyxidiophora seems very close, or perhaps identical, to one that Meredith Blackwell and I studied in the late 1980's.  Ours produced similar synnemata and ascomata to yours.  It was on moose dung in northern Ontario, Canada.  After studying this and other species of Pyxidiophora we concluded that it was impossible to name this and other species accurately until  further work could be done on the life histories and genetics of Pyxidiophora species.

Attached is a pdf of our paper.

Regards,
Dave

Hello David.

We can refine the determination if Sven gets measured the beak and the cells that compose it, and the body of perithecium? The shape and size of spores is I believe also important also with the presence or absence of a dark spot at maturity. I know this very complex type whose species are difficult to ascertain.

Regards.

Michel.

Hello Michel..
I am not certain that measurements of the perithecium will be much additional help.  The species can be very similar to one another yet differ considerably in how the ascospores germinate when attached to their mite host.  The anamorphs on the dung substrate also differ a lot.  

I think the species of Pyxidiophora are numerous and perhaps mostly undescribed.  They occur on many substrates, including dung, decaying plant materials and old mushrooms.  They appear to have some degree of host-specificity as well.  I find them commonly on decaying seaweed on the beach where they seem to have different preferences for their hyphomycetous host.

There are some types available in herbaria, but these generally lack anamorphs and of course we have no idea of how the spores germinate.  Ascospores sizes vary within certain limits, but these limits probably encompass many species.  Dark spots will appear on most ascospores (all in my experience) at maturity. 

This is a really challenging genus that is worthy of a Ph.D. project.

Dave

David thank you for your opinion and all these details very interesting.

Michel.

There is also the paper Doveri and Coupé in the Documents Mycologiques  (Tome xxxiv Fascicule 133-134 2006); this work is more recent.

Michel.

Hi Michel,
you could send me this work?
Thank you Peter.

Hello,

thanks for your reply! Could you send me too this work of Doveri? I am very interested!

Sven

I have this document on paper, with no scanner I would try to make pictures soon.

Michel.

Here you can download the full article as pdf.

https://www.researchgate.net/publication/278312910_First_record_of_Pyxidiophora_badiorostris_from_France

Best wishes
Norbert

Thank you very much.
Greetings Peter.
Also with the newer treatise it remains by my estimation.

Best thanks for the link! I am the same opinion like Peter that this fungus is near P. avernensis.

Sven

In my opinion too!

Michel.