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Shamalama

Possible Parasolenopleura Ouangondiana Trilobite?

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Shamalama

Hey guys, I picked up this trilobite this spring at my local show and rediscovered it today while cleaning up.

post-1408-0-94582200-1408931444_thumb.jpg

The label states it is a "Braintreela sp. cf. ouangondiana" from the Lower Cambrian, Chamberlains Brook Fm, Adeyton Group, Manuels, Newfoundland, Canada. Problem is I can't find any references to "Braintreela" online but I did find a paper that referenced Parasolenopleura ouangondiana that comes from the same formation.

http://onlinelibrary.wiley.com/doi/10.1111/j.1475-4983.2005.00494.x/pdf

The plates in the paper seem to match what I have so am I correct to modify my label to indicate the name change?

Thanks for looking,

Dave

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piranha

That paper you linked has Braintreella, you just have to add an extra 'L'. The solenopleurids you mention have very similar features, but if it were in my collection I'd be inclined to stick with the accompanying label. Attached for comparison is a line drawing of Braintreella aculeata, also from Chamberlain's Brook Formation. The figured cephalon of B. ouangondiana doesn't match quite as well, so at a minimum you might label it as Braintreella sp.

 

Congrats on a spectacular Newfie trilobite! :fistbump:

IMG1.jpg

 

Boyce, W.D. (1988)
St. John's 1988 Field Trip Guidebook. Trip A8. Cambrian Trilobite Faunas on the Avalon Peninsula, Newfoundland.
Geological Association of Canada - Mineralogical Association of Canada - Canadian Society of Petroleum Geologists
 
 
 

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FossilDAWG

Congrats on a cool trilobite. I believe the Manuels Brook site is has now been made a park and the fossils are "protected" from collectors, though presumably not from the ravages of erosion. All of which makes your specimen even more rare.

Don

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Shamalama

Scott - You are correct! Trying to read .pdf files on a monitor can be difficult sometimes and I totally missed that. Upon a closer (enlarged) reading I see that the author indicates that Braintreella rogersi is known from Massachusetts but that it is poorly preserved there.

Parasolenopleura is closely related to Braintreella Wheeler, 1942, as represented by B. rogersi in the Paradoxides
(Hydrocephalus) harlani zonal assemblage of Massachusetts (Geyer and Landing 2001; Fletcher et al. 2005).
However, due to the inadequate preservation of B. rogersi, Braintreella is restricted to the Massachusetts
material, as it is difficult to make meaningful comparison with better-preserved material. Specimens of the
same general form as Braintreella occur in a similar P. (H.) harlani assemblage in the Wester Cove of Branch
Cove, Newfoundland (Fletcher et al. 2005; Textfig. 5A–F), but they generally display better-preserved
features comparable with species assigned to Parasolenopleura and are here regarded as an undescribed new
species of Parasolenopleura close to the Moroccan ‘Atopiaspis’ tikasraynensis Geyer, 1998. Among these features,
the morphology of the cranidium is variable and involves differences in the amounts of glabellar tapering,
the anterior shape of the glabella, the convexity or sunken nature of the preglabellar field, the sharpness or
bluntness of the occipital spine, the relative widths of the fixigenae and the sagittal length of the anterior border.
Such a significant spectrum of variation is similar to that described by other authors, notably Hughes
(1994) and Blaker and Peel (1997, p. 124), and therefore Parasolenopleura is best regarded as a highly variable
form incorporating junior synonymous genera (Fletcher et al. 2005), e.g. Atopiaspis Geyer, 1998.

So if I interpret the author correctly, Braintreella does not occur in Newfoundland and is instead referred to as Parasolenopleura sp. It also seems that the whole taxonomic family is a little jumbled.

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Shamalama

Congrats on a cool trilobite. I believe the Manuels Brook site is has now been made a park and the fossils are "protected" from collectors, though presumably not from the ravages of erosion. All of which makes your specimen even more rare.

Don

Thanks Don. Too bad about that site being off limits.

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piranha
On 8/25/2014 at 4:44 AM, Shamalama said:

Scott - You are correct! Trying to read .pdf files on a monitor can be difficult sometimes and I totally missed that. Upon a closer (enlarged) reading I see that the author indicates that Braintreella rogersi is known from Massachusetts but that it is poorly preserved there.

So if I interpret the author correctly, Braintreella does not occur in Newfoundland and is instead referred to as Parasolenopleura sp. It also seems that the whole taxonomic family is a little jumbled.

 

 

Evidently that question is still open to interpretation. Subsequent papers list Braintreella in Newfoundland, including another one by Fletcher in 2006. Braintreella? is applied to an incomplete, slightly distorted cranidium and suggested for another undetermined solenopleurid (Landing et al. 2008). For the latest info I'd suggest contacting Doug Boyce as the top authority on all the Newfoundland trilobites.

 

Landing, E.; Johnson, S.C., & Geyer, G. (2008)
Faunas and Cambrian Volcanism on the Avalonian Marginal Platform, Southern New Brunswick.
Journal of Paleontology, 82(5):884-905
 
Fletcher, T.P. (2006)
Bedrock Geology of the Cape St. Mary's Peninsula, Southwest Avalon Peninsula, Newfoundland.
Newfoundland and Labrador Department of Natural Resources, Geological Survey, Current Research, Report 2006-2:1-117
 
 
 

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Shamalama

Gotcha. I'll leave the label as is for now but maybe put a note with it referring to the papers and possible alternate taxonomy.

Thanks for your help Scott!

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Fossildude19

Don't know how I missed this at the time, but great acquisition, Dave! :)

Looks like it is all there if it were prepped out some.

Regards,

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Williamrock

What kind of stone are they usually found in ?

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