Ordovician Brachiopods Unknown

[JUAN EMMANUEL]

These unidentifiable brachs have been bugging me for some time now. Any Ordovician collectors familiar with these?? Are these perhaps a species of Dalmanella? They come from Toronto, Georgian Bay Formation, late Ordovician.

[JUAN EMMANUEL]

And each shell is approximately 1 centimetre long and they are all the same species.

Edited July 29, 2014 by JUAN EMMANUEL

[Herb]

they look like Hebertellla?

[FossilDAWG]

Check out Catazyga headii. I collected specimens almost identical to yours from the Georgian Bay Formation in Toronto.

Don

Edited July 29, 2014 by FossilDAWG

[JUAN EMMANUEL]

Thanks for the suggestions guys.

Don, Catazyga seems kinda way too globular for the shape of this one . Do you happen to have any other suggestions? Or is it what it could be? I don't how to put it, but the shell has this distinctive v-shaped cleavage on it and there are also other shells of the same species which have a convex other-side shell.

[JUAN EMMANUEL]

For size, I almost forgot:

[Ludwigia]

How about Zygospira modesta or another species thereof ?

Edited July 29, 2014 by Ludwigia

[erose]

i'm with Herb. Very Hebertellaish. Too big for Zygospira and Catazyga does not have a sulcus.

[Ludwigia]

i'm with Herb. Very Hebertellaish. Too big for Zygospira and Catazyga does not have a sulcus.

On second thought, I'll go with that.

[JUAN EMMANUEL]

Thanks for the opinion guys. I'll definitely checkout Hebertella. I've never red anything about Hebertella being found in the Georgian Bay Formation yet.......

[piranha]

Hebertella occidentalis(?) is recorded from Georgian Bay but the attached North American species look different than the posted examples. They also look similar to a couple of Doleroides sp. I've seen from Ontario.

 

 

Wright, D.F., & Stigall, A.L. (2013)

Phylogenetic revision of the Late Ordovician orthid brachiopod genera Plaesiomys and Hebertella from Laurentia.

Journal of Paleontology, 87(6):1107-1128

 

 

 

[Scott S.]

HI There,

Haven't posted in a LONG time. I'm not very familiar with the Georgian Bay formation but I do specialize in brachiopods. I can say with 95% assurance that these are likely not Hebertella. The hinge line here appears to be anastrophic meaning curved and Hebertella is an orthid which all have straight (strophic) hinge lines. Furthermore the interarea seems way too small since I can see the recurved beak of the opposite valve so easily. These very likely belong to the genus Anazyga but I'm not sure of the species but they look a little too large to be A. recurvirostra or A. deflecta which are known from the Bobcaygeon, Verulam and Cobourg formations. I also considered Doleroides or Pionodema but again these would have larger interareas and are also orthids. Lastly if not a representative of Anazyga, they might belong to Zygospira. I've seen a reference to "Hallina canadensi" which according to pbdb.org has been reclassified as a species of Zygospira, but admittedly, I'm not familiar with it. Hope this at least provides some other leads for you.

Cheers