What species of Niobe trilobite?

[syl1219s]

Hi!

I wanna know about species of Niobe.

Seller told me that it from russia.

 

What species of this trilobite? 

And Are there regions where fossils in such conditions(black color, Flattened) are found?

The Russian fossils I know of are only the caramel-colored fossils found in St. Petersburg.

 

 

 

[Kane]

The Baltoscandian plate that houses the Ordovician trilobites from the Iapetus Ocean extends through Russia, Estonia, Norway, Finland, and parts of Sweden. This specimen is not from St Petersburg. Also, you may wish to consider Niobella, given that Niobe typically have visible pygidial ribbing. 

[Isotelus2883]

This might be Chinese (though the quality of prep suggests otherwise)?

[Kane]

The black shell can be indicative of Norwegian examples.

[trilobites_are_awesome]

@piranha

[piranha]

This one is a mystery. I have shown it to 8 experts that are highly specialized with asaphid trilobites, and no one recognizes the ID. Please attempt to discover where it was actually collected and post any additional specimens if they become available. In the meantime label it: Asaphida sp.

[Isotelus2883]

Zhiyia tsinghaiensis might be a match!

https://www.app.pan.pl/archive/published/app68/app011022023.pdf

[piranha]

Great minds really do think alike...another specialist friend just suggested that as well:

 

"As Liexiaspis shows the same preservation, I would definitely go for Zhiyia tsinghaiensis."

[syl1219s]

I was feeling discouraged because I couldn't get any additional information from the seller,
thank you so much for all yours help!

[piranha]

I have an exciting update to report. The mystery trilobite is not Zhiyia tsinghaiensis from the Duoquanshan Formation, Shihuigou, Northwestern Qinghai Province.

 

Instead it is Zhiyia sp. —an undescribed species from the Madaoyu Formation, Liexi, Western Hunan Province.

Wei & Zhou 2023 referenced: Asaphid gen. et sp. indet. from: Chen et al. (2023: 107–109, figs. 6–12).

Unfortunately, I did not yet have the publication of Chen et al. 2023.

 

 

Because all the figured specimens of Zhiyia tsinghaiensis from Wei & Zhou 2023, and from the original description of Chang & Fan 1960, did not have thoracic segments, I thought there was a good possibility that this nearly complete and articulated specimen would be a match with Zhiyia sp. described from Wei & Zhou 2023:

"The middle Floian Asaphid gen. et sp. indet. of Chen et al. (2023: 107–109, figs. 6–12) from the Madaoyu Formation of western Hunan Province is also considered to belong to the new genus on the basis of its almost obsolete cephalic and pygidial axial furrows, a flattened anterior border of the cranidium, a narrow occipital ring, an oval hypostome with a shallow median notch and bilobed posterior projections, and a subsemicircular pygidium with a wide border.

Of the Early Ordovician (middle Floian) species from Liexi, western Hunan Province, Asaphid gen. et sp. indet. collected from the Madaoyu Formation (see Chen et al. 2023: 107–109, figs. 6–12) is comparable with Z. tsinghaiensis particularly in its almost obsolete cephalic and pygidial axial furrows, but the former has a narrower cranidium, shallower preglabellar and occipital furrows, a longer pygidium, and smooth surface of the cranidium and pygidium. As is noted above it should be assigned to the new genus Zhiyia, and distinguished from all other described species, but until additional specimens become available, a new taxon is not formally introduced."

************************************************************************************************************************************************

 

 

The description does not mention whether or not Zhiyia sp. is complete or if the thoracic segments are preserved, so on a hunch, I contacted the primary author, Xin Wei, for additional details. As luck would have it, my hunch was correct. All of the specimens of Zhiyia tsinghaiensis are almost always disarticulated and buried separately due to a high-energy depositional environment on a shallow-water carbonate platform. However, those specimens collected from the Madaoyu Formation are almost always complete, and were found on a deep-water packstone environment. The figures of Zhiyia sp. (=asaphid sp. indet.) from Chen et al. 2023 are attached. Zhiyia sp. will be formally described in an upcoming paper.

 

 

Chang, W.T., Fan, J.S. 1960
Ordovician and Silurian Trilobites of the Qilian Mountains.
Geological Gazetter of the Qilian Mountains, 4(1):83-148  [in Chinese]

 

Chen, H.M., Zhou, J., Ding, L. 2023
The Liexi Fauna of the Early Ordovician in Western Hunan Province.
Treasure, 1:99-113  [in Chinese]

 

Wei X., Zhou, Z.Q. 2023
Floian, Early Ordovician, Trilobites from the Olongbluk Terrane, Northwest China.
Acta Palaeontologica Polonica, 68(4):683-693